From 3a1720af1d7f43edc5b214cde0be11bfb94d077e Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Wed, 23 Oct 2019 17:52:22 +0000 Subject: Vendor import of stripped compiler-rt trunk r375505, the last commit before the upstream Subversion repository was made read-only, and the LLVM project migrated to GitHub: https://llvm.org/svn/llvm-project/compiler-rt/trunk@375505 --- lib/dfsan/dfsan.cc | 460 --------------- lib/dfsan/dfsan.cpp | 460 +++++++++++++++ lib/dfsan/dfsan_custom.cc | 1156 -------------------------------------- lib/dfsan/dfsan_custom.cpp | 1156 ++++++++++++++++++++++++++++++++++++++ lib/dfsan/dfsan_interceptors.cc | 45 -- lib/dfsan/dfsan_interceptors.cpp | 45 ++ 6 files changed, 1661 insertions(+), 1661 deletions(-) delete mode 100644 lib/dfsan/dfsan.cc create mode 100644 lib/dfsan/dfsan.cpp delete mode 100644 lib/dfsan/dfsan_custom.cc create mode 100644 lib/dfsan/dfsan_custom.cpp delete mode 100644 lib/dfsan/dfsan_interceptors.cc create mode 100644 lib/dfsan/dfsan_interceptors.cpp (limited to 'lib/dfsan') diff --git a/lib/dfsan/dfsan.cc b/lib/dfsan/dfsan.cc deleted file mode 100644 index f4ba1148f782..000000000000 --- a/lib/dfsan/dfsan.cc +++ /dev/null @@ -1,460 +0,0 @@ -//===-- dfsan.cc ----------------------------------------------------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file is a part of DataFlowSanitizer. -// -// DataFlowSanitizer runtime. This file defines the public interface to -// DataFlowSanitizer as well as the definition of certain runtime functions -// called automatically by the compiler (specifically the instrumentation pass -// in llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp). -// -// The public interface is defined in include/sanitizer/dfsan_interface.h whose -// functions are prefixed dfsan_ while the compiler interface functions are -// prefixed __dfsan_. -//===----------------------------------------------------------------------===// - -#include "sanitizer_common/sanitizer_atomic.h" -#include "sanitizer_common/sanitizer_common.h" -#include "sanitizer_common/sanitizer_file.h" -#include "sanitizer_common/sanitizer_flags.h" -#include "sanitizer_common/sanitizer_flag_parser.h" -#include "sanitizer_common/sanitizer_libc.h" - -#include "dfsan/dfsan.h" - -using namespace __dfsan; - -typedef atomic_uint16_t atomic_dfsan_label; -static const dfsan_label kInitializingLabel = -1; - -static const uptr kNumLabels = 1 << (sizeof(dfsan_label) * 8); - -static atomic_dfsan_label __dfsan_last_label; -static dfsan_label_info __dfsan_label_info[kNumLabels]; - -Flags __dfsan::flags_data; - -SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_retval_tls; -SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_arg_tls[64]; - -SANITIZER_INTERFACE_ATTRIBUTE uptr __dfsan_shadow_ptr_mask; - -// On Linux/x86_64, memory is laid out as follows: -// -// +--------------------+ 0x800000000000 (top of memory) -// | application memory | -// +--------------------+ 0x700000008000 (kAppAddr) -// | | -// | unused | -// | | -// +--------------------+ 0x200200000000 (kUnusedAddr) -// | union table | -// +--------------------+ 0x200000000000 (kUnionTableAddr) -// | shadow memory | -// +--------------------+ 0x000000010000 (kShadowAddr) -// | reserved by kernel | -// +--------------------+ 0x000000000000 -// -// To derive a shadow memory address from an application memory address, -// bits 44-46 are cleared to bring the address into the range -// [0x000000008000,0x100000000000). Then the address is shifted left by 1 to -// account for the double byte representation of shadow labels and move the -// address into the shadow memory range. See the function shadow_for below. - -// On Linux/MIPS64, memory is laid out as follows: -// -// +--------------------+ 0x10000000000 (top of memory) -// | application memory | -// +--------------------+ 0xF000008000 (kAppAddr) -// | | -// | unused | -// | | -// +--------------------+ 0x2200000000 (kUnusedAddr) -// | union table | -// +--------------------+ 0x2000000000 (kUnionTableAddr) -// | shadow memory | -// +--------------------+ 0x0000010000 (kShadowAddr) -// | reserved by kernel | -// +--------------------+ 0x0000000000 - -// On Linux/AArch64 (39-bit VMA), memory is laid out as follow: -// -// +--------------------+ 0x8000000000 (top of memory) -// | application memory | -// +--------------------+ 0x7000008000 (kAppAddr) -// | | -// | unused | -// | | -// +--------------------+ 0x1200000000 (kUnusedAddr) -// | union table | -// +--------------------+ 0x1000000000 (kUnionTableAddr) -// | shadow memory | -// +--------------------+ 0x0000010000 (kShadowAddr) -// | reserved by kernel | -// +--------------------+ 0x0000000000 - -// On Linux/AArch64 (42-bit VMA), memory is laid out as follow: -// -// +--------------------+ 0x40000000000 (top of memory) -// | application memory | -// +--------------------+ 0x3ff00008000 (kAppAddr) -// | | -// | unused | -// | | -// +--------------------+ 0x1200000000 (kUnusedAddr) -// | union table | -// +--------------------+ 0x8000000000 (kUnionTableAddr) -// | shadow memory | -// +--------------------+ 0x0000010000 (kShadowAddr) -// | reserved by kernel | -// +--------------------+ 0x0000000000 - -// On Linux/AArch64 (48-bit VMA), memory is laid out as follow: -// -// +--------------------+ 0x1000000000000 (top of memory) -// | application memory | -// +--------------------+ 0xffff00008000 (kAppAddr) -// | unused | -// +--------------------+ 0xaaaab0000000 (top of PIE address) -// | application PIE | -// +--------------------+ 0xaaaaa0000000 (top of PIE address) -// | | -// | unused | -// | | -// +--------------------+ 0x1200000000 (kUnusedAddr) -// | union table | -// +--------------------+ 0x8000000000 (kUnionTableAddr) -// | shadow memory | -// +--------------------+ 0x0000010000 (kShadowAddr) -// | reserved by kernel | -// +--------------------+ 0x0000000000 - -typedef atomic_dfsan_label dfsan_union_table_t[kNumLabels][kNumLabels]; - -#ifdef DFSAN_RUNTIME_VMA -// Runtime detected VMA size. -int __dfsan::vmaSize; -#endif - -static uptr UnusedAddr() { - return MappingArchImpl() - + sizeof(dfsan_union_table_t); -} - -static atomic_dfsan_label *union_table(dfsan_label l1, dfsan_label l2) { - return &(*(dfsan_union_table_t *) UnionTableAddr())[l1][l2]; -} - -// Checks we do not run out of labels. -static void dfsan_check_label(dfsan_label label) { - if (label == kInitializingLabel) { - Report("FATAL: DataFlowSanitizer: out of labels\n"); - Die(); - } -} - -// Resolves the union of two unequal labels. Nonequality is a precondition for -// this function (the instrumentation pass inlines the equality test). -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -dfsan_label __dfsan_union(dfsan_label l1, dfsan_label l2) { - if (flags().fast16labels) - return l1 | l2; - DCHECK_NE(l1, l2); - - if (l1 == 0) - return l2; - if (l2 == 0) - return l1; - - if (l1 > l2) - Swap(l1, l2); - - atomic_dfsan_label *table_ent = union_table(l1, l2); - // We need to deal with the case where two threads concurrently request - // a union of the same pair of labels. If the table entry is uninitialized, - // (i.e. 0) use a compare-exchange to set the entry to kInitializingLabel - // (i.e. -1) to mark that we are initializing it. - dfsan_label label = 0; - if (atomic_compare_exchange_strong(table_ent, &label, kInitializingLabel, - memory_order_acquire)) { - // Check whether l2 subsumes l1. We don't need to check whether l1 - // subsumes l2 because we are guaranteed here that l1 < l2, and (at least - // in the cases we are interested in) a label may only subsume labels - // created earlier (i.e. with a lower numerical value). - if (__dfsan_label_info[l2].l1 == l1 || - __dfsan_label_info[l2].l2 == l1) { - label = l2; - } else { - label = - atomic_fetch_add(&__dfsan_last_label, 1, memory_order_relaxed) + 1; - dfsan_check_label(label); - __dfsan_label_info[label].l1 = l1; - __dfsan_label_info[label].l2 = l2; - } - atomic_store(table_ent, label, memory_order_release); - } else if (label == kInitializingLabel) { - // Another thread is initializing the entry. Wait until it is finished. - do { - internal_sched_yield(); - label = atomic_load(table_ent, memory_order_acquire); - } while (label == kInitializingLabel); - } - return label; -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -dfsan_label __dfsan_union_load(const dfsan_label *ls, uptr n) { - dfsan_label label = ls[0]; - for (uptr i = 1; i != n; ++i) { - dfsan_label next_label = ls[i]; - if (label != next_label) - label = __dfsan_union(label, next_label); - } - return label; -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -void __dfsan_unimplemented(char *fname) { - if (flags().warn_unimplemented) - Report("WARNING: DataFlowSanitizer: call to uninstrumented function %s\n", - fname); -} - -// Use '-mllvm -dfsan-debug-nonzero-labels' and break on this function -// to try to figure out where labels are being introduced in a nominally -// label-free program. -extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __dfsan_nonzero_label() { - if (flags().warn_nonzero_labels) - Report("WARNING: DataFlowSanitizer: saw nonzero label\n"); -} - -// Indirect call to an uninstrumented vararg function. We don't have a way of -// handling these at the moment. -extern "C" SANITIZER_INTERFACE_ATTRIBUTE void -__dfsan_vararg_wrapper(const char *fname) { - Report("FATAL: DataFlowSanitizer: unsupported indirect call to vararg " - "function %s\n", fname); - Die(); -} - -// Like __dfsan_union, but for use from the client or custom functions. Hence -// the equality comparison is done here before calling __dfsan_union. -SANITIZER_INTERFACE_ATTRIBUTE dfsan_label -dfsan_union(dfsan_label l1, dfsan_label l2) { - if (l1 == l2) - return l1; - return __dfsan_union(l1, l2); -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -dfsan_label dfsan_create_label(const char *desc, void *userdata) { - dfsan_label label = - atomic_fetch_add(&__dfsan_last_label, 1, memory_order_relaxed) + 1; - dfsan_check_label(label); - __dfsan_label_info[label].l1 = __dfsan_label_info[label].l2 = 0; - __dfsan_label_info[label].desc = desc; - __dfsan_label_info[label].userdata = userdata; - return label; -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -void __dfsan_set_label(dfsan_label label, void *addr, uptr size) { - for (dfsan_label *labelp = shadow_for(addr); size != 0; --size, ++labelp) { - // Don't write the label if it is already the value we need it to be. - // In a program where most addresses are not labeled, it is common that - // a page of shadow memory is entirely zeroed. The Linux copy-on-write - // implementation will share all of the zeroed pages, making a copy of a - // page when any value is written. The un-sharing will happen even if - // the value written does not change the value in memory. Avoiding the - // write when both |label| and |*labelp| are zero dramatically reduces - // the amount of real memory used by large programs. - if (label == *labelp) - continue; - - *labelp = label; - } -} - -SANITIZER_INTERFACE_ATTRIBUTE -void dfsan_set_label(dfsan_label label, void *addr, uptr size) { - __dfsan_set_label(label, addr, size); -} - -SANITIZER_INTERFACE_ATTRIBUTE -void dfsan_add_label(dfsan_label label, void *addr, uptr size) { - for (dfsan_label *labelp = shadow_for(addr); size != 0; --size, ++labelp) - if (*labelp != label) - *labelp = __dfsan_union(*labelp, label); -} - -// Unlike the other dfsan interface functions the behavior of this function -// depends on the label of one of its arguments. Hence it is implemented as a -// custom function. -extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label -__dfsw_dfsan_get_label(long data, dfsan_label data_label, - dfsan_label *ret_label) { - *ret_label = 0; - return data_label; -} - -SANITIZER_INTERFACE_ATTRIBUTE dfsan_label -dfsan_read_label(const void *addr, uptr size) { - if (size == 0) - return 0; - return __dfsan_union_load(shadow_for(addr), size); -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE -const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label) { - return &__dfsan_label_info[label]; -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE int -dfsan_has_label(dfsan_label label, dfsan_label elem) { - if (label == elem) - return true; - const dfsan_label_info *info = dfsan_get_label_info(label); - if (info->l1 != 0) { - return dfsan_has_label(info->l1, elem) || dfsan_has_label(info->l2, elem); - } else { - return false; - } -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label -dfsan_has_label_with_desc(dfsan_label label, const char *desc) { - const dfsan_label_info *info = dfsan_get_label_info(label); - if (info->l1 != 0) { - return dfsan_has_label_with_desc(info->l1, desc) || - dfsan_has_label_with_desc(info->l2, desc); - } else { - return internal_strcmp(desc, info->desc) == 0; - } -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE uptr -dfsan_get_label_count(void) { - dfsan_label max_label_allocated = - atomic_load(&__dfsan_last_label, memory_order_relaxed); - - return static_cast(max_label_allocated); -} - -extern "C" SANITIZER_INTERFACE_ATTRIBUTE void -dfsan_dump_labels(int fd) { - dfsan_label last_label = - atomic_load(&__dfsan_last_label, memory_order_relaxed); - - for (uptr l = 1; l <= last_label; ++l) { - char buf[64]; - internal_snprintf(buf, sizeof(buf), "%u %u %u ", l, - __dfsan_label_info[l].l1, __dfsan_label_info[l].l2); - WriteToFile(fd, buf, internal_strlen(buf)); - if (__dfsan_label_info[l].l1 == 0 && __dfsan_label_info[l].desc) { - WriteToFile(fd, __dfsan_label_info[l].desc, - internal_strlen(__dfsan_label_info[l].desc)); - } - WriteToFile(fd, "\n", 1); - } -} - -void Flags::SetDefaults() { -#define DFSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue; -#include "dfsan_flags.inc" -#undef DFSAN_FLAG -} - -static void RegisterDfsanFlags(FlagParser *parser, Flags *f) { -#define DFSAN_FLAG(Type, Name, DefaultValue, Description) \ - RegisterFlag(parser, #Name, Description, &f->Name); -#include "dfsan_flags.inc" -#undef DFSAN_FLAG -} - -static void InitializeFlags() { - SetCommonFlagsDefaults(); - flags().SetDefaults(); - - FlagParser parser; - RegisterCommonFlags(&parser); - RegisterDfsanFlags(&parser, &flags()); - parser.ParseStringFromEnv("DFSAN_OPTIONS"); - InitializeCommonFlags(); - if (Verbosity()) ReportUnrecognizedFlags(); - if (common_flags()->help) parser.PrintFlagDescriptions(); -} - -static void InitializePlatformEarly() { - AvoidCVE_2016_2143(); -#ifdef DFSAN_RUNTIME_VMA - __dfsan::vmaSize = - (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1); - if (__dfsan::vmaSize == 39 || __dfsan::vmaSize == 42 || - __dfsan::vmaSize == 48) { - __dfsan_shadow_ptr_mask = ShadowMask(); - } else { - Printf("FATAL: DataFlowSanitizer: unsupported VMA range\n"); - Printf("FATAL: Found %d - Supported 39, 42, and 48\n", __dfsan::vmaSize); - Die(); - } -#endif -} - -static void dfsan_fini() { - if (internal_strcmp(flags().dump_labels_at_exit, "") != 0) { - fd_t fd = OpenFile(flags().dump_labels_at_exit, WrOnly); - if (fd == kInvalidFd) { - Report("WARNING: DataFlowSanitizer: unable to open output file %s\n", - flags().dump_labels_at_exit); - return; - } - - Report("INFO: DataFlowSanitizer: dumping labels to %s\n", - flags().dump_labels_at_exit); - dfsan_dump_labels(fd); - CloseFile(fd); - } -} - -extern "C" void dfsan_flush() { - UnmapOrDie((void*)ShadowAddr(), UnusedAddr() - ShadowAddr()); - if (!MmapFixedNoReserve(ShadowAddr(), UnusedAddr() - ShadowAddr())) - Die(); -} - -static void dfsan_init(int argc, char **argv, char **envp) { - InitializeFlags(); - - ::InitializePlatformEarly(); - - if (!MmapFixedNoReserve(ShadowAddr(), UnusedAddr() - ShadowAddr())) - Die(); - - // Protect the region of memory we don't use, to preserve the one-to-one - // mapping from application to shadow memory. But if ASLR is disabled, Linux - // will load our executable in the middle of our unused region. This mostly - // works so long as the program doesn't use too much memory. We support this - // case by disabling memory protection when ASLR is disabled. - uptr init_addr = (uptr)&dfsan_init; - if (!(init_addr >= UnusedAddr() && init_addr < AppAddr())) - MmapFixedNoAccess(UnusedAddr(), AppAddr() - UnusedAddr()); - - InitializeInterceptors(); - - // Register the fini callback to run when the program terminates successfully - // or it is killed by the runtime. - Atexit(dfsan_fini); - AddDieCallback(dfsan_fini); - - __dfsan_label_info[kInitializingLabel].desc = ""; -} - -#if SANITIZER_CAN_USE_PREINIT_ARRAY -__attribute__((section(".preinit_array"), used)) -static void (*dfsan_init_ptr)(int, char **, char **) = dfsan_init; -#endif diff --git a/lib/dfsan/dfsan.cpp b/lib/dfsan/dfsan.cpp new file mode 100644 index 000000000000..0e2fb9f5f334 --- /dev/null +++ b/lib/dfsan/dfsan.cpp @@ -0,0 +1,460 @@ +//===-- dfsan.cpp ---------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of DataFlowSanitizer. +// +// DataFlowSanitizer runtime. This file defines the public interface to +// DataFlowSanitizer as well as the definition of certain runtime functions +// called automatically by the compiler (specifically the instrumentation pass +// in llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp). +// +// The public interface is defined in include/sanitizer/dfsan_interface.h whose +// functions are prefixed dfsan_ while the compiler interface functions are +// prefixed __dfsan_. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_atomic.h" +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_file.h" +#include "sanitizer_common/sanitizer_flags.h" +#include "sanitizer_common/sanitizer_flag_parser.h" +#include "sanitizer_common/sanitizer_libc.h" + +#include "dfsan/dfsan.h" + +using namespace __dfsan; + +typedef atomic_uint16_t atomic_dfsan_label; +static const dfsan_label kInitializingLabel = -1; + +static const uptr kNumLabels = 1 << (sizeof(dfsan_label) * 8); + +static atomic_dfsan_label __dfsan_last_label; +static dfsan_label_info __dfsan_label_info[kNumLabels]; + +Flags __dfsan::flags_data; + +SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_retval_tls; +SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_arg_tls[64]; + +SANITIZER_INTERFACE_ATTRIBUTE uptr __dfsan_shadow_ptr_mask; + +// On Linux/x86_64, memory is laid out as follows: +// +// +--------------------+ 0x800000000000 (top of memory) +// | application memory | +// +--------------------+ 0x700000008000 (kAppAddr) +// | | +// | unused | +// | | +// +--------------------+ 0x200200000000 (kUnusedAddr) +// | union table | +// +--------------------+ 0x200000000000 (kUnionTableAddr) +// | shadow memory | +// +--------------------+ 0x000000010000 (kShadowAddr) +// | reserved by kernel | +// +--------------------+ 0x000000000000 +// +// To derive a shadow memory address from an application memory address, +// bits 44-46 are cleared to bring the address into the range +// [0x000000008000,0x100000000000). Then the address is shifted left by 1 to +// account for the double byte representation of shadow labels and move the +// address into the shadow memory range. See the function shadow_for below. + +// On Linux/MIPS64, memory is laid out as follows: +// +// +--------------------+ 0x10000000000 (top of memory) +// | application memory | +// +--------------------+ 0xF000008000 (kAppAddr) +// | | +// | unused | +// | | +// +--------------------+ 0x2200000000 (kUnusedAddr) +// | union table | +// +--------------------+ 0x2000000000 (kUnionTableAddr) +// | shadow memory | +// +--------------------+ 0x0000010000 (kShadowAddr) +// | reserved by kernel | +// +--------------------+ 0x0000000000 + +// On Linux/AArch64 (39-bit VMA), memory is laid out as follow: +// +// +--------------------+ 0x8000000000 (top of memory) +// | application memory | +// +--------------------+ 0x7000008000 (kAppAddr) +// | | +// | unused | +// | | +// +--------------------+ 0x1200000000 (kUnusedAddr) +// | union table | +// +--------------------+ 0x1000000000 (kUnionTableAddr) +// | shadow memory | +// +--------------------+ 0x0000010000 (kShadowAddr) +// | reserved by kernel | +// +--------------------+ 0x0000000000 + +// On Linux/AArch64 (42-bit VMA), memory is laid out as follow: +// +// +--------------------+ 0x40000000000 (top of memory) +// | application memory | +// +--------------------+ 0x3ff00008000 (kAppAddr) +// | | +// | unused | +// | | +// +--------------------+ 0x1200000000 (kUnusedAddr) +// | union table | +// +--------------------+ 0x8000000000 (kUnionTableAddr) +// | shadow memory | +// +--------------------+ 0x0000010000 (kShadowAddr) +// | reserved by kernel | +// +--------------------+ 0x0000000000 + +// On Linux/AArch64 (48-bit VMA), memory is laid out as follow: +// +// +--------------------+ 0x1000000000000 (top of memory) +// | application memory | +// +--------------------+ 0xffff00008000 (kAppAddr) +// | unused | +// +--------------------+ 0xaaaab0000000 (top of PIE address) +// | application PIE | +// +--------------------+ 0xaaaaa0000000 (top of PIE address) +// | | +// | unused | +// | | +// +--------------------+ 0x1200000000 (kUnusedAddr) +// | union table | +// +--------------------+ 0x8000000000 (kUnionTableAddr) +// | shadow memory | +// +--------------------+ 0x0000010000 (kShadowAddr) +// | reserved by kernel | +// +--------------------+ 0x0000000000 + +typedef atomic_dfsan_label dfsan_union_table_t[kNumLabels][kNumLabels]; + +#ifdef DFSAN_RUNTIME_VMA +// Runtime detected VMA size. +int __dfsan::vmaSize; +#endif + +static uptr UnusedAddr() { + return MappingArchImpl() + + sizeof(dfsan_union_table_t); +} + +static atomic_dfsan_label *union_table(dfsan_label l1, dfsan_label l2) { + return &(*(dfsan_union_table_t *) UnionTableAddr())[l1][l2]; +} + +// Checks we do not run out of labels. +static void dfsan_check_label(dfsan_label label) { + if (label == kInitializingLabel) { + Report("FATAL: DataFlowSanitizer: out of labels\n"); + Die(); + } +} + +// Resolves the union of two unequal labels. Nonequality is a precondition for +// this function (the instrumentation pass inlines the equality test). +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +dfsan_label __dfsan_union(dfsan_label l1, dfsan_label l2) { + if (flags().fast16labels) + return l1 | l2; + DCHECK_NE(l1, l2); + + if (l1 == 0) + return l2; + if (l2 == 0) + return l1; + + if (l1 > l2) + Swap(l1, l2); + + atomic_dfsan_label *table_ent = union_table(l1, l2); + // We need to deal with the case where two threads concurrently request + // a union of the same pair of labels. If the table entry is uninitialized, + // (i.e. 0) use a compare-exchange to set the entry to kInitializingLabel + // (i.e. -1) to mark that we are initializing it. + dfsan_label label = 0; + if (atomic_compare_exchange_strong(table_ent, &label, kInitializingLabel, + memory_order_acquire)) { + // Check whether l2 subsumes l1. We don't need to check whether l1 + // subsumes l2 because we are guaranteed here that l1 < l2, and (at least + // in the cases we are interested in) a label may only subsume labels + // created earlier (i.e. with a lower numerical value). + if (__dfsan_label_info[l2].l1 == l1 || + __dfsan_label_info[l2].l2 == l1) { + label = l2; + } else { + label = + atomic_fetch_add(&__dfsan_last_label, 1, memory_order_relaxed) + 1; + dfsan_check_label(label); + __dfsan_label_info[label].l1 = l1; + __dfsan_label_info[label].l2 = l2; + } + atomic_store(table_ent, label, memory_order_release); + } else if (label == kInitializingLabel) { + // Another thread is initializing the entry. Wait until it is finished. + do { + internal_sched_yield(); + label = atomic_load(table_ent, memory_order_acquire); + } while (label == kInitializingLabel); + } + return label; +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +dfsan_label __dfsan_union_load(const dfsan_label *ls, uptr n) { + dfsan_label label = ls[0]; + for (uptr i = 1; i != n; ++i) { + dfsan_label next_label = ls[i]; + if (label != next_label) + label = __dfsan_union(label, next_label); + } + return label; +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +void __dfsan_unimplemented(char *fname) { + if (flags().warn_unimplemented) + Report("WARNING: DataFlowSanitizer: call to uninstrumented function %s\n", + fname); +} + +// Use '-mllvm -dfsan-debug-nonzero-labels' and break on this function +// to try to figure out where labels are being introduced in a nominally +// label-free program. +extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __dfsan_nonzero_label() { + if (flags().warn_nonzero_labels) + Report("WARNING: DataFlowSanitizer: saw nonzero label\n"); +} + +// Indirect call to an uninstrumented vararg function. We don't have a way of +// handling these at the moment. +extern "C" SANITIZER_INTERFACE_ATTRIBUTE void +__dfsan_vararg_wrapper(const char *fname) { + Report("FATAL: DataFlowSanitizer: unsupported indirect call to vararg " + "function %s\n", fname); + Die(); +} + +// Like __dfsan_union, but for use from the client or custom functions. Hence +// the equality comparison is done here before calling __dfsan_union. +SANITIZER_INTERFACE_ATTRIBUTE dfsan_label +dfsan_union(dfsan_label l1, dfsan_label l2) { + if (l1 == l2) + return l1; + return __dfsan_union(l1, l2); +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +dfsan_label dfsan_create_label(const char *desc, void *userdata) { + dfsan_label label = + atomic_fetch_add(&__dfsan_last_label, 1, memory_order_relaxed) + 1; + dfsan_check_label(label); + __dfsan_label_info[label].l1 = __dfsan_label_info[label].l2 = 0; + __dfsan_label_info[label].desc = desc; + __dfsan_label_info[label].userdata = userdata; + return label; +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +void __dfsan_set_label(dfsan_label label, void *addr, uptr size) { + for (dfsan_label *labelp = shadow_for(addr); size != 0; --size, ++labelp) { + // Don't write the label if it is already the value we need it to be. + // In a program where most addresses are not labeled, it is common that + // a page of shadow memory is entirely zeroed. The Linux copy-on-write + // implementation will share all of the zeroed pages, making a copy of a + // page when any value is written. The un-sharing will happen even if + // the value written does not change the value in memory. Avoiding the + // write when both |label| and |*labelp| are zero dramatically reduces + // the amount of real memory used by large programs. + if (label == *labelp) + continue; + + *labelp = label; + } +} + +SANITIZER_INTERFACE_ATTRIBUTE +void dfsan_set_label(dfsan_label label, void *addr, uptr size) { + __dfsan_set_label(label, addr, size); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void dfsan_add_label(dfsan_label label, void *addr, uptr size) { + for (dfsan_label *labelp = shadow_for(addr); size != 0; --size, ++labelp) + if (*labelp != label) + *labelp = __dfsan_union(*labelp, label); +} + +// Unlike the other dfsan interface functions the behavior of this function +// depends on the label of one of its arguments. Hence it is implemented as a +// custom function. +extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label +__dfsw_dfsan_get_label(long data, dfsan_label data_label, + dfsan_label *ret_label) { + *ret_label = 0; + return data_label; +} + +SANITIZER_INTERFACE_ATTRIBUTE dfsan_label +dfsan_read_label(const void *addr, uptr size) { + if (size == 0) + return 0; + return __dfsan_union_load(shadow_for(addr), size); +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE +const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label) { + return &__dfsan_label_info[label]; +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE int +dfsan_has_label(dfsan_label label, dfsan_label elem) { + if (label == elem) + return true; + const dfsan_label_info *info = dfsan_get_label_info(label); + if (info->l1 != 0) { + return dfsan_has_label(info->l1, elem) || dfsan_has_label(info->l2, elem); + } else { + return false; + } +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label +dfsan_has_label_with_desc(dfsan_label label, const char *desc) { + const dfsan_label_info *info = dfsan_get_label_info(label); + if (info->l1 != 0) { + return dfsan_has_label_with_desc(info->l1, desc) || + dfsan_has_label_with_desc(info->l2, desc); + } else { + return internal_strcmp(desc, info->desc) == 0; + } +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE uptr +dfsan_get_label_count(void) { + dfsan_label max_label_allocated = + atomic_load(&__dfsan_last_label, memory_order_relaxed); + + return static_cast(max_label_allocated); +} + +extern "C" SANITIZER_INTERFACE_ATTRIBUTE void +dfsan_dump_labels(int fd) { + dfsan_label last_label = + atomic_load(&__dfsan_last_label, memory_order_relaxed); + + for (uptr l = 1; l <= last_label; ++l) { + char buf[64]; + internal_snprintf(buf, sizeof(buf), "%u %u %u ", l, + __dfsan_label_info[l].l1, __dfsan_label_info[l].l2); + WriteToFile(fd, buf, internal_strlen(buf)); + if (__dfsan_label_info[l].l1 == 0 && __dfsan_label_info[l].desc) { + WriteToFile(fd, __dfsan_label_info[l].desc, + internal_strlen(__dfsan_label_info[l].desc)); + } + WriteToFile(fd, "\n", 1); + } +} + +void Flags::SetDefaults() { +#define DFSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue; +#include "dfsan_flags.inc" +#undef DFSAN_FLAG +} + +static void RegisterDfsanFlags(FlagParser *parser, Flags *f) { +#define DFSAN_FLAG(Type, Name, DefaultValue, Description) \ + RegisterFlag(parser, #Name, Description, &f->Name); +#include "dfsan_flags.inc" +#undef DFSAN_FLAG +} + +static void InitializeFlags() { + SetCommonFlagsDefaults(); + flags().SetDefaults(); + + FlagParser parser; + RegisterCommonFlags(&parser); + RegisterDfsanFlags(&parser, &flags()); + parser.ParseStringFromEnv("DFSAN_OPTIONS"); + InitializeCommonFlags(); + if (Verbosity()) ReportUnrecognizedFlags(); + if (common_flags()->help) parser.PrintFlagDescriptions(); +} + +static void InitializePlatformEarly() { + AvoidCVE_2016_2143(); +#ifdef DFSAN_RUNTIME_VMA + __dfsan::vmaSize = + (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1); + if (__dfsan::vmaSize == 39 || __dfsan::vmaSize == 42 || + __dfsan::vmaSize == 48) { + __dfsan_shadow_ptr_mask = ShadowMask(); + } else { + Printf("FATAL: DataFlowSanitizer: unsupported VMA range\n"); + Printf("FATAL: Found %d - Supported 39, 42, and 48\n", __dfsan::vmaSize); + Die(); + } +#endif +} + +static void dfsan_fini() { + if (internal_strcmp(flags().dump_labels_at_exit, "") != 0) { + fd_t fd = OpenFile(flags().dump_labels_at_exit, WrOnly); + if (fd == kInvalidFd) { + Report("WARNING: DataFlowSanitizer: unable to open output file %s\n", + flags().dump_labels_at_exit); + return; + } + + Report("INFO: DataFlowSanitizer: dumping labels to %s\n", + flags().dump_labels_at_exit); + dfsan_dump_labels(fd); + CloseFile(fd); + } +} + +extern "C" void dfsan_flush() { + UnmapOrDie((void*)ShadowAddr(), UnusedAddr() - ShadowAddr()); + if (!MmapFixedNoReserve(ShadowAddr(), UnusedAddr() - ShadowAddr())) + Die(); +} + +static void dfsan_init(int argc, char **argv, char **envp) { + InitializeFlags(); + + ::InitializePlatformEarly(); + + if (!MmapFixedNoReserve(ShadowAddr(), UnusedAddr() - ShadowAddr())) + Die(); + + // Protect the region of memory we don't use, to preserve the one-to-one + // mapping from application to shadow memory. But if ASLR is disabled, Linux + // will load our executable in the middle of our unused region. This mostly + // works so long as the program doesn't use too much memory. We support this + // case by disabling memory protection when ASLR is disabled. + uptr init_addr = (uptr)&dfsan_init; + if (!(init_addr >= UnusedAddr() && init_addr < AppAddr())) + MmapFixedNoAccess(UnusedAddr(), AppAddr() - UnusedAddr()); + + InitializeInterceptors(); + + // Register the fini callback to run when the program terminates successfully + // or it is killed by the runtime. + Atexit(dfsan_fini); + AddDieCallback(dfsan_fini); + + __dfsan_label_info[kInitializingLabel].desc = ""; +} + +#if SANITIZER_CAN_USE_PREINIT_ARRAY +__attribute__((section(".preinit_array"), used)) +static void (*dfsan_init_ptr)(int, char **, char **) = dfsan_init; +#endif diff --git a/lib/dfsan/dfsan_custom.cc b/lib/dfsan/dfsan_custom.cc deleted file mode 100644 index dc7b81da4566..000000000000 --- a/lib/dfsan/dfsan_custom.cc +++ /dev/null @@ -1,1156 +0,0 @@ -//===-- dfsan.cc ----------------------------------------------------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file is a part of DataFlowSanitizer. -// -// This file defines the custom functions listed in done_abilist.txt. -//===----------------------------------------------------------------------===// - -#include "sanitizer_common/sanitizer_common.h" -#include "sanitizer_common/sanitizer_internal_defs.h" -#include "sanitizer_common/sanitizer_linux.h" - -#include "dfsan/dfsan.h" - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -using namespace __dfsan; - -#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \ - do { \ - if (f) \ - f(__VA_ARGS__); \ - } while (false) -#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \ -SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__); - -extern "C" { -SANITIZER_INTERFACE_ATTRIBUTE int -__dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label, - dfsan_label buf_label, dfsan_label *ret_label) { - int ret = stat(path, buf); - if (ret == 0) - dfsan_set_label(0, buf, sizeof(struct stat)); - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf, - dfsan_label fd_label, - dfsan_label buf_label, - dfsan_label *ret_label) { - int ret = fstat(fd, buf); - if (ret == 0) - dfsan_set_label(0, buf, sizeof(struct stat)); - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c, - dfsan_label s_label, - dfsan_label c_label, - dfsan_label *ret_label) { - for (size_t i = 0;; ++i) { - if (s[i] == c || s[i] == 0) { - if (flags().strict_data_dependencies) { - *ret_label = s_label; - } else { - *ret_label = dfsan_union(dfsan_read_label(s, i + 1), - dfsan_union(s_label, c_label)); - } - return s[i] == 0 ? nullptr : const_cast(s+i); - } - } -} - -DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc, - const void *s1, const void *s2, size_t n, - dfsan_label s1_label, dfsan_label s2_label, - dfsan_label n_label) - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2, - size_t n, dfsan_label s1_label, - dfsan_label s2_label, - dfsan_label n_label, - dfsan_label *ret_label) { - CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n, - s1_label, s2_label, n_label); - const char *cs1 = (const char *) s1, *cs2 = (const char *) s2; - for (size_t i = 0; i != n; ++i) { - if (cs1[i] != cs2[i]) { - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1), - dfsan_read_label(cs2, i + 1)); - } - return cs1[i] - cs2[i]; - } - } - - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(cs1, n), - dfsan_read_label(cs2, n)); - } - return 0; -} - -DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc, - const char *s1, const char *s2, - dfsan_label s1_label, dfsan_label s2_label) - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2, - dfsan_label s1_label, - dfsan_label s2_label, - dfsan_label *ret_label) { - CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2, - s1_label, s2_label); - for (size_t i = 0;; ++i) { - if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) { - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), - dfsan_read_label(s2, i + 1)); - } - return s1[i] - s2[i]; - } - } - return 0; -} - -SANITIZER_INTERFACE_ATTRIBUTE int -__dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label, - dfsan_label s2_label, dfsan_label *ret_label) { - for (size_t i = 0;; ++i) { - if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) { - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), - dfsan_read_label(s2, i + 1)); - } - return s1[i] - s2[i]; - } - } - return 0; -} - -DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc, - const char *s1, const char *s2, size_t n, - dfsan_label s1_label, dfsan_label s2_label, - dfsan_label n_label) - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2, - size_t n, dfsan_label s1_label, - dfsan_label s2_label, - dfsan_label n_label, - dfsan_label *ret_label) { - if (n == 0) { - *ret_label = 0; - return 0; - } - - CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2, - n, s1_label, s2_label, n_label); - - for (size_t i = 0;; ++i) { - if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) { - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), - dfsan_read_label(s2, i + 1)); - } - return s1[i] - s2[i]; - } - } - return 0; -} - -SANITIZER_INTERFACE_ATTRIBUTE int -__dfsw_strncasecmp(const char *s1, const char *s2, size_t n, - dfsan_label s1_label, dfsan_label s2_label, - dfsan_label n_label, dfsan_label *ret_label) { - if (n == 0) { - *ret_label = 0; - return 0; - } - - for (size_t i = 0;; ++i) { - if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 || - i == n - 1) { - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), - dfsan_read_label(s2, i + 1)); - } - return s1[i] - s2[i]; - } - } - return 0; -} - -SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size, - dfsan_label nmemb_label, - dfsan_label size_label, - dfsan_label *ret_label) { - void *p = calloc(nmemb, size); - dfsan_set_label(0, p, nmemb * size); - *ret_label = 0; - return p; -} - -SANITIZER_INTERFACE_ATTRIBUTE size_t -__dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) { - size_t ret = strlen(s); - if (flags().strict_data_dependencies) { - *ret_label = 0; - } else { - *ret_label = dfsan_read_label(s, ret + 1); - } - return ret; -} - - -static void *dfsan_memcpy(void *dest, const void *src, size_t n) { - dfsan_label *sdest = shadow_for(dest); - const dfsan_label *ssrc = shadow_for(src); - internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label)); - return internal_memcpy(dest, src, n); -} - -static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) { - internal_memset(s, c, n); - dfsan_set_label(c_label, s, n); -} - -SANITIZER_INTERFACE_ATTRIBUTE -void *__dfsw_memcpy(void *dest, const void *src, size_t n, - dfsan_label dest_label, dfsan_label src_label, - dfsan_label n_label, dfsan_label *ret_label) { - *ret_label = dest_label; - return dfsan_memcpy(dest, src, n); -} - -SANITIZER_INTERFACE_ATTRIBUTE -void *__dfsw_memset(void *s, int c, size_t n, - dfsan_label s_label, dfsan_label c_label, - dfsan_label n_label, dfsan_label *ret_label) { - dfsan_memset(s, c, c_label, n); - *ret_label = s_label; - return s; -} - -SANITIZER_INTERFACE_ATTRIBUTE char * -__dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) { - size_t len = strlen(s); - void *p = malloc(len+1); - dfsan_memcpy(p, s, len+1); - *ret_label = 0; - return static_cast(p); -} - -SANITIZER_INTERFACE_ATTRIBUTE char * -__dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label, - dfsan_label s2_label, dfsan_label n_label, - dfsan_label *ret_label) { - size_t len = strlen(s2); - if (len < n) { - dfsan_memcpy(s1, s2, len+1); - dfsan_memset(s1+len+1, 0, 0, n-len-1); - } else { - dfsan_memcpy(s1, s2, n); - } - - *ret_label = s1_label; - return s1; -} - -SANITIZER_INTERFACE_ATTRIBUTE ssize_t -__dfsw_pread(int fd, void *buf, size_t count, off_t offset, - dfsan_label fd_label, dfsan_label buf_label, - dfsan_label count_label, dfsan_label offset_label, - dfsan_label *ret_label) { - ssize_t ret = pread(fd, buf, count, offset); - if (ret > 0) - dfsan_set_label(0, buf, ret); - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE ssize_t -__dfsw_read(int fd, void *buf, size_t count, - dfsan_label fd_label, dfsan_label buf_label, - dfsan_label count_label, - dfsan_label *ret_label) { - ssize_t ret = read(fd, buf, count); - if (ret > 0) - dfsan_set_label(0, buf, ret); - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id, - struct timespec *tp, - dfsan_label clk_id_label, - dfsan_label tp_label, - dfsan_label *ret_label) { - int ret = clock_gettime(clk_id, tp); - if (ret == 0) - dfsan_set_label(0, tp, sizeof(struct timespec)); - *ret_label = 0; - return ret; -} - -static void unpoison(const void *ptr, uptr size) { - dfsan_set_label(0, const_cast(ptr), size); -} - -// dlopen() ultimately calls mmap() down inside the loader, which generally -// doesn't participate in dynamic symbol resolution. Therefore we won't -// intercept its calls to mmap, and we have to hook it here. -SANITIZER_INTERFACE_ATTRIBUTE void * -__dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label, - dfsan_label flag_label, dfsan_label *ret_label) { - void *handle = dlopen(filename, flag); - link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle); - if (map) - ForEachMappedRegion(map, unpoison); - *ret_label = 0; - return handle; -} - -struct pthread_create_info { - void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *); - void *start_routine; - void *arg; -}; - -static void *pthread_create_cb(void *p) { - pthread_create_info pci(*(pthread_create_info *)p); - free(p); - dfsan_label ret_label; - return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0, - &ret_label); -} - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create( - pthread_t *thread, const pthread_attr_t *attr, - void *(*start_routine_trampoline)(void *, void *, dfsan_label, - dfsan_label *), - void *start_routine, void *arg, dfsan_label thread_label, - dfsan_label attr_label, dfsan_label start_routine_label, - dfsan_label arg_label, dfsan_label *ret_label) { - pthread_create_info *pci = - (pthread_create_info *)malloc(sizeof(pthread_create_info)); - pci->start_routine_trampoline = start_routine_trampoline; - pci->start_routine = start_routine; - pci->arg = arg; - int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci); - if (rv != 0) - free(pci); - *ret_label = 0; - return rv; -} - -struct dl_iterate_phdr_info { - int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, - size_t size, void *data, dfsan_label info_label, - dfsan_label size_label, dfsan_label data_label, - dfsan_label *ret_label); - void *callback; - void *data; -}; - -int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) { - dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data; - dfsan_set_label(0, *info); - dfsan_set_label(0, const_cast(info->dlpi_name), - strlen(info->dlpi_name) + 1); - dfsan_set_label( - 0, const_cast(reinterpret_cast(info->dlpi_phdr)), - sizeof(*info->dlpi_phdr) * info->dlpi_phnum); - dfsan_label ret_label; - return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0, - 0, &ret_label); -} - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr( - int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, - size_t size, void *data, dfsan_label info_label, - dfsan_label size_label, dfsan_label data_label, - dfsan_label *ret_label), - void *callback, void *data, dfsan_label callback_label, - dfsan_label data_label, dfsan_label *ret_label) { - dl_iterate_phdr_info dipi = { callback_trampoline, callback, data }; - *ret_label = 0; - return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); -} - -SANITIZER_INTERFACE_ATTRIBUTE -char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label, - dfsan_label buf_label, dfsan_label *ret_label) { - char *ret = ctime_r(timep, buf); - if (ret) { - dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf, - strlen(buf) + 1); - *ret_label = buf_label; - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label, - dfsan_label size_label, dfsan_label stream_label, - dfsan_label *ret_label) { - char *ret = fgets(s, size, stream); - if (ret) { - dfsan_set_label(0, ret, strlen(ret) + 1); - *ret_label = s_label; - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label, - dfsan_label size_label, dfsan_label *ret_label) { - char *ret = getcwd(buf, size); - if (ret) { - dfsan_set_label(0, ret, strlen(ret) + 1); - *ret_label = buf_label; - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -char *__dfsw_get_current_dir_name(dfsan_label *ret_label) { - char *ret = get_current_dir_name(); - if (ret) { - dfsan_set_label(0, ret, strlen(ret) + 1); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label, - dfsan_label len_label, dfsan_label *ret_label) { - int ret = gethostname(name, len); - if (ret == 0) { - dfsan_set_label(0, name, strlen(name) + 1); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_getrlimit(int resource, struct rlimit *rlim, - dfsan_label resource_label, dfsan_label rlim_label, - dfsan_label *ret_label) { - int ret = getrlimit(resource, rlim); - if (ret == 0) { - dfsan_set_label(0, rlim, sizeof(struct rlimit)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label, - dfsan_label usage_label, dfsan_label *ret_label) { - int ret = getrusage(who, usage); - if (ret == 0) { - dfsan_set_label(0, usage, sizeof(struct rusage)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label, - dfsan_label src_label, dfsan_label *ret_label) { - char *ret = strcpy(dest, src); - if (ret) { - internal_memcpy(shadow_for(dest), shadow_for(src), - sizeof(dfsan_label) * (strlen(src) + 1)); - } - *ret_label = dst_label; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -long int __dfsw_strtol(const char *nptr, char **endptr, int base, - dfsan_label nptr_label, dfsan_label endptr_label, - dfsan_label base_label, dfsan_label *ret_label) { - char *tmp_endptr; - long int ret = strtol(nptr, &tmp_endptr, base); - if (endptr) { - *endptr = tmp_endptr; - } - if (tmp_endptr > nptr) { - // If *tmp_endptr is '\0' include its label as well. - *ret_label = dfsan_union( - base_label, - dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -double __dfsw_strtod(const char *nptr, char **endptr, - dfsan_label nptr_label, dfsan_label endptr_label, - dfsan_label *ret_label) { - char *tmp_endptr; - double ret = strtod(nptr, &tmp_endptr); - if (endptr) { - *endptr = tmp_endptr; - } - if (tmp_endptr > nptr) { - // If *tmp_endptr is '\0' include its label as well. - *ret_label = dfsan_read_label( - nptr, - tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -long long int __dfsw_strtoll(const char *nptr, char **endptr, int base, - dfsan_label nptr_label, dfsan_label endptr_label, - dfsan_label base_label, dfsan_label *ret_label) { - char *tmp_endptr; - long long int ret = strtoll(nptr, &tmp_endptr, base); - if (endptr) { - *endptr = tmp_endptr; - } - if (tmp_endptr > nptr) { - // If *tmp_endptr is '\0' include its label as well. - *ret_label = dfsan_union( - base_label, - dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base, - dfsan_label nptr_label, dfsan_label endptr_label, - dfsan_label base_label, dfsan_label *ret_label) { - char *tmp_endptr; - unsigned long int ret = strtoul(nptr, &tmp_endptr, base); - if (endptr) { - *endptr = tmp_endptr; - } - if (tmp_endptr > nptr) { - // If *tmp_endptr is '\0' include its label as well. - *ret_label = dfsan_union( - base_label, - dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr, - dfsan_label nptr_label, - int base, dfsan_label endptr_label, - dfsan_label base_label, - dfsan_label *ret_label) { - char *tmp_endptr; - long long unsigned int ret = strtoull(nptr, &tmp_endptr, base); - if (endptr) { - *endptr = tmp_endptr; - } - if (tmp_endptr > nptr) { - // If *tmp_endptr is '\0' include its label as well. - *ret_label = dfsan_union( - base_label, - dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) { - time_t ret = time(t); - if (ret != (time_t) -1 && t) { - dfsan_set_label(0, t, sizeof(time_t)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label, - dfsan_label src_label, dfsan_label dst_label, - dfsan_label *ret_label) { - int ret = inet_pton(af, src, dst); - if (ret == 1) { - dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst, - af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result, - dfsan_label timep_label, dfsan_label result_label, - dfsan_label *ret_label) { - struct tm *ret = localtime_r(timep, result); - if (ret) { - dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result, - sizeof(struct tm)); - *ret_label = result_label; - } else { - *ret_label = 0; - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd, - char *buf, size_t buflen, struct passwd **result, - dfsan_label uid_label, dfsan_label pwd_label, - dfsan_label buf_label, dfsan_label buflen_label, - dfsan_label result_label, dfsan_label *ret_label) { - // Store the data in pwd, the strings referenced from pwd in buf, and the - // address of pwd in *result. On failure, NULL is stored in *result. - int ret = getpwuid_r(uid, pwd, buf, buflen, result); - if (ret == 0) { - dfsan_set_label(0, pwd, sizeof(struct passwd)); - dfsan_set_label(0, buf, strlen(buf) + 1); - } - *ret_label = 0; - dfsan_set_label(0, result, sizeof(struct passwd*)); - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout, - dfsan_label dfs_label, dfsan_label nfds_label, - dfsan_label timeout_label, dfsan_label *ret_label) { - int ret = poll(fds, nfds, timeout); - if (ret >= 0) { - for (; nfds > 0; --nfds) { - dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents)); - } - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds, - fd_set *exceptfds, struct timeval *timeout, - dfsan_label nfds_label, dfsan_label readfds_label, - dfsan_label writefds_label, dfsan_label exceptfds_label, - dfsan_label timeout_label, dfsan_label *ret_label) { - int ret = select(nfds, readfds, writefds, exceptfds, timeout); - // Clear everything (also on error) since their content is either set or - // undefined. - if (readfds) { - dfsan_set_label(0, readfds, sizeof(fd_set)); - } - if (writefds) { - dfsan_set_label(0, writefds, sizeof(fd_set)); - } - if (exceptfds) { - dfsan_set_label(0, exceptfds, sizeof(fd_set)); - } - dfsan_set_label(0, timeout, sizeof(struct timeval)); - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask, - dfsan_label pid_label, - dfsan_label cpusetsize_label, - dfsan_label mask_label, dfsan_label *ret_label) { - int ret = sched_getaffinity(pid, cpusetsize, mask); - if (ret == 0) { - dfsan_set_label(0, mask, cpusetsize); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label, - dfsan_label *ret_label) { - int ret = sigemptyset(set); - dfsan_set_label(0, set, sizeof(sigset_t)); - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_sigaction(int signum, const struct sigaction *act, - struct sigaction *oldact, dfsan_label signum_label, - dfsan_label act_label, dfsan_label oldact_label, - dfsan_label *ret_label) { - int ret = sigaction(signum, act, oldact); - if (oldact) { - dfsan_set_label(0, oldact, sizeof(struct sigaction)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz, - dfsan_label tv_label, dfsan_label tz_label, - dfsan_label *ret_label) { - int ret = gettimeofday(tv, tz); - if (tv) { - dfsan_set_label(0, tv, sizeof(struct timeval)); - } - if (tz) { - dfsan_set_label(0, tz, sizeof(struct timezone)); - } - *ret_label = 0; - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n, - dfsan_label s_label, - dfsan_label c_label, - dfsan_label n_label, - dfsan_label *ret_label) { - void *ret = memchr(s, c, n); - if (flags().strict_data_dependencies) { - *ret_label = ret ? s_label : 0; - } else { - size_t len = - ret ? reinterpret_cast(ret) - reinterpret_cast(s) + 1 - : n; - *ret_label = - dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label)); - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c, - dfsan_label s_label, - dfsan_label c_label, - dfsan_label *ret_label) { - char *ret = strrchr(s, c); - if (flags().strict_data_dependencies) { - *ret_label = ret ? s_label : 0; - } else { - *ret_label = - dfsan_union(dfsan_read_label(s, strlen(s) + 1), - dfsan_union(s_label, c_label)); - } - - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle, - dfsan_label haystack_label, - dfsan_label needle_label, - dfsan_label *ret_label) { - char *ret = strstr(haystack, needle); - if (flags().strict_data_dependencies) { - *ret_label = ret ? haystack_label : 0; - } else { - size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1; - *ret_label = - dfsan_union(dfsan_read_label(haystack, len), - dfsan_union(dfsan_read_label(needle, strlen(needle) + 1), - dfsan_union(haystack_label, needle_label))); - } - - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req, - struct timespec *rem, - dfsan_label req_label, - dfsan_label rem_label, - dfsan_label *ret_label) { - int ret = nanosleep(req, rem); - *ret_label = 0; - if (ret == -1) { - // Interrupted by a signal, rem is filled with the remaining time. - dfsan_set_label(0, rem, sizeof(struct timespec)); - } - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE int -__dfsw_socketpair(int domain, int type, int protocol, int sv[2], - dfsan_label domain_label, dfsan_label type_label, - dfsan_label protocol_label, dfsan_label sv_label, - dfsan_label *ret_label) { - int ret = socketpair(domain, type, protocol, sv); - *ret_label = 0; - if (ret == 0) { - dfsan_set_label(0, sv, sizeof(*sv) * 2); - } - return ret; -} - -// Type of the trampoline function passed to the custom version of -// dfsan_set_write_callback. -typedef void (*write_trampoline_t)( - void *callback, - int fd, const void *buf, ssize_t count, - dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label); - -// Calls to dfsan_set_write_callback() set the values in this struct. -// Calls to the custom version of write() read (and invoke) them. -static struct { - write_trampoline_t write_callback_trampoline = nullptr; - void *write_callback = nullptr; -} write_callback_info; - -SANITIZER_INTERFACE_ATTRIBUTE void -__dfsw_dfsan_set_write_callback( - write_trampoline_t write_callback_trampoline, - void *write_callback, - dfsan_label write_callback_label, - dfsan_label *ret_label) { - write_callback_info.write_callback_trampoline = write_callback_trampoline; - write_callback_info.write_callback = write_callback; -} - -SANITIZER_INTERFACE_ATTRIBUTE int -__dfsw_write(int fd, const void *buf, size_t count, - dfsan_label fd_label, dfsan_label buf_label, - dfsan_label count_label, dfsan_label *ret_label) { - if (write_callback_info.write_callback) { - write_callback_info.write_callback_trampoline( - write_callback_info.write_callback, - fd, buf, count, - fd_label, buf_label, count_label); - } - - *ret_label = 0; - return write(fd, buf, count); -} -} // namespace __dfsan - -// Type used to extract a dfsan_label with va_arg() -typedef int dfsan_label_va; - -// Formats a chunk either a constant string or a single format directive (e.g., -// '%.3f'). -struct Formatter { - Formatter(char *str_, const char *fmt_, size_t size_) - : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_), - width(-1) {} - - int format() { - char *tmp_fmt = build_format_string(); - int retval = - snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt, - 0 /* used only to avoid warnings */); - free(tmp_fmt); - return retval; - } - - template int format(T arg) { - char *tmp_fmt = build_format_string(); - int retval; - if (width >= 0) { - retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, - tmp_fmt, width, arg); - } else { - retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, - tmp_fmt, arg); - } - free(tmp_fmt); - return retval; - } - - char *build_format_string() { - size_t fmt_size = fmt_cur - fmt_start + 1; - char *new_fmt = (char *)malloc(fmt_size + 1); - assert(new_fmt); - internal_memcpy(new_fmt, fmt_start, fmt_size); - new_fmt[fmt_size] = '\0'; - return new_fmt; - } - - char *str_cur() { return str + str_off; } - - size_t num_written_bytes(int retval) { - if (retval < 0) { - return 0; - } - - size_t num_avail = str_off < size ? size - str_off : 0; - if (num_avail == 0) { - return 0; - } - - size_t num_written = retval; - // A return value of {v,}snprintf of size or more means that the output was - // truncated. - if (num_written >= num_avail) { - num_written -= num_avail; - } - - return num_written; - } - - char *str; - size_t str_off; - size_t size; - const char *fmt_start; - const char *fmt_cur; - int width; -}; - -// Formats the input and propagates the input labels to the output. The output -// is stored in 'str'. 'size' bounds the number of output bytes. 'format' and -// 'ap' are the format string and the list of arguments for formatting. Returns -// the return value vsnprintf would return. -// -// The function tokenizes the format string in chunks representing either a -// constant string or a single format directive (e.g., '%.3f') and formats each -// chunk independently into the output string. This approach allows to figure -// out which bytes of the output string depends on which argument and thus to -// propagate labels more precisely. -// -// WARNING: This implementation does not support conversion specifiers with -// positional arguments. -static int format_buffer(char *str, size_t size, const char *fmt, - dfsan_label *va_labels, dfsan_label *ret_label, - va_list ap) { - Formatter formatter(str, fmt, size); - - while (*formatter.fmt_cur) { - formatter.fmt_start = formatter.fmt_cur; - formatter.width = -1; - int retval = 0; - - if (*formatter.fmt_cur != '%') { - // Ordinary character. Consume all the characters until a '%' or the end - // of the string. - for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%'; - ++formatter.fmt_cur) {} - retval = formatter.format(); - dfsan_set_label(0, formatter.str_cur(), - formatter.num_written_bytes(retval)); - } else { - // Conversion directive. Consume all the characters until a conversion - // specifier or the end of the string. - bool end_fmt = false; - for (; *formatter.fmt_cur && !end_fmt; ) { - switch (*++formatter.fmt_cur) { - case 'd': - case 'i': - case 'o': - case 'u': - case 'x': - case 'X': - switch (*(formatter.fmt_cur - 1)) { - case 'h': - // Also covers the 'hh' case (since the size of the arg is still - // an int). - retval = formatter.format(va_arg(ap, int)); - break; - case 'l': - if (formatter.fmt_cur - formatter.fmt_start >= 2 && - *(formatter.fmt_cur - 2) == 'l') { - retval = formatter.format(va_arg(ap, long long int)); - } else { - retval = formatter.format(va_arg(ap, long int)); - } - break; - case 'q': - retval = formatter.format(va_arg(ap, long long int)); - break; - case 'j': - retval = formatter.format(va_arg(ap, intmax_t)); - break; - case 'z': - case 't': - retval = formatter.format(va_arg(ap, size_t)); - break; - default: - retval = formatter.format(va_arg(ap, int)); - } - dfsan_set_label(*va_labels++, formatter.str_cur(), - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - - case 'a': - case 'A': - case 'e': - case 'E': - case 'f': - case 'F': - case 'g': - case 'G': - if (*(formatter.fmt_cur - 1) == 'L') { - retval = formatter.format(va_arg(ap, long double)); - } else { - retval = formatter.format(va_arg(ap, double)); - } - dfsan_set_label(*va_labels++, formatter.str_cur(), - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - - case 'c': - retval = formatter.format(va_arg(ap, int)); - dfsan_set_label(*va_labels++, formatter.str_cur(), - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - - case 's': { - char *arg = va_arg(ap, char *); - retval = formatter.format(arg); - va_labels++; - internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg), - sizeof(dfsan_label) * - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - } - - case 'p': - retval = formatter.format(va_arg(ap, void *)); - dfsan_set_label(*va_labels++, formatter.str_cur(), - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - - case 'n': { - int *ptr = va_arg(ap, int *); - *ptr = (int)formatter.str_off; - va_labels++; - dfsan_set_label(0, ptr, sizeof(ptr)); - end_fmt = true; - break; - } - - case '%': - retval = formatter.format(); - dfsan_set_label(0, formatter.str_cur(), - formatter.num_written_bytes(retval)); - end_fmt = true; - break; - - case '*': - formatter.width = va_arg(ap, int); - va_labels++; - break; - - default: - break; - } - } - } - - if (retval < 0) { - return retval; - } - - formatter.fmt_cur++; - formatter.str_off += retval; - } - - *ret_label = 0; - - // Number of bytes written in total. - return formatter.str_off; -} - -extern "C" { -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label, - dfsan_label format_label, dfsan_label *va_labels, - dfsan_label *ret_label, ...) { - va_list ap; - va_start(ap, ret_label); - int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap); - va_end(ap); - return ret; -} - -SANITIZER_INTERFACE_ATTRIBUTE -int __dfsw_snprintf(char *str, size_t size, const char *format, - dfsan_label str_label, dfsan_label size_label, - dfsan_label format_label, dfsan_label *va_labels, - dfsan_label *ret_label, ...) { - va_list ap; - va_start(ap, ret_label); - int ret = format_buffer(str, size, format, va_labels, ret_label, ap); - va_end(ap); - return ret; -} - -// Default empty implementations (weak). Users should redefine them. -SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *, - u32 *) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {} - -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1, - void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2, - void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4, - void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8, - void) {} -SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {} -} // extern "C" diff --git a/lib/dfsan/dfsan_custom.cpp b/lib/dfsan/dfsan_custom.cpp new file mode 100644 index 000000000000..84f0271b15e0 --- /dev/null +++ b/lib/dfsan/dfsan_custom.cpp @@ -0,0 +1,1156 @@ +//===-- dfsan.cpp ---------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of DataFlowSanitizer. +// +// This file defines the custom functions listed in done_abilist.txt. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_internal_defs.h" +#include "sanitizer_common/sanitizer_linux.h" + +#include "dfsan/dfsan.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +using namespace __dfsan; + +#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \ + do { \ + if (f) \ + f(__VA_ARGS__); \ + } while (false) +#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \ +SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__); + +extern "C" { +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label, + dfsan_label buf_label, dfsan_label *ret_label) { + int ret = stat(path, buf); + if (ret == 0) + dfsan_set_label(0, buf, sizeof(struct stat)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf, + dfsan_label fd_label, + dfsan_label buf_label, + dfsan_label *ret_label) { + int ret = fstat(fd, buf); + if (ret == 0) + dfsan_set_label(0, buf, sizeof(struct stat)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label *ret_label) { + for (size_t i = 0;; ++i) { + if (s[i] == c || s[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = s_label; + } else { + *ret_label = dfsan_union(dfsan_read_label(s, i + 1), + dfsan_union(s_label, c_label)); + } + return s[i] == 0 ? nullptr : const_cast(s+i); + } + } +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc, + const void *s1, const void *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2, + size_t n, dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label n_label, + dfsan_label *ret_label) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n, + s1_label, s2_label, n_label); + const char *cs1 = (const char *) s1, *cs2 = (const char *) s2; + for (size_t i = 0; i != n; ++i) { + if (cs1[i] != cs2[i]) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1), + dfsan_read_label(cs2, i + 1)); + } + return cs1[i] - cs2[i]; + } + } + + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(cs1, n), + dfsan_read_label(cs2, n)); + } + return 0; +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc, + const char *s1, const char *s2, + dfsan_label s1_label, dfsan_label s2_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2, + dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label *ret_label) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2, + s1_label, s2_label); + for (size_t i = 0;; ++i) { + if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label, + dfsan_label s2_label, dfsan_label *ret_label) { + for (size_t i = 0;; ++i) { + if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc, + const char *s1, const char *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2, + size_t n, dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label n_label, + dfsan_label *ret_label) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2, + n, s1_label, s2_label, n_label); + + for (size_t i = 0;; ++i) { + if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_strncasecmp(const char *s1, const char *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label, dfsan_label *ret_label) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + for (size_t i = 0;; ++i) { + if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 || + i == n - 1) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size, + dfsan_label nmemb_label, + dfsan_label size_label, + dfsan_label *ret_label) { + void *p = calloc(nmemb, size); + dfsan_set_label(0, p, nmemb * size); + *ret_label = 0; + return p; +} + +SANITIZER_INTERFACE_ATTRIBUTE size_t +__dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) { + size_t ret = strlen(s); + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_read_label(s, ret + 1); + } + return ret; +} + + +static void *dfsan_memcpy(void *dest, const void *src, size_t n) { + dfsan_label *sdest = shadow_for(dest); + const dfsan_label *ssrc = shadow_for(src); + internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label)); + return internal_memcpy(dest, src, n); +} + +static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) { + internal_memset(s, c, n); + dfsan_set_label(c_label, s, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfsw_memcpy(void *dest, const void *src, size_t n, + dfsan_label dest_label, dfsan_label src_label, + dfsan_label n_label, dfsan_label *ret_label) { + *ret_label = dest_label; + return dfsan_memcpy(dest, src, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfsw_memset(void *s, int c, size_t n, + dfsan_label s_label, dfsan_label c_label, + dfsan_label n_label, dfsan_label *ret_label) { + dfsan_memset(s, c, c_label, n); + *ret_label = s_label; + return s; +} + +SANITIZER_INTERFACE_ATTRIBUTE char * +__dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) { + size_t len = strlen(s); + void *p = malloc(len+1); + dfsan_memcpy(p, s, len+1); + *ret_label = 0; + return static_cast(p); +} + +SANITIZER_INTERFACE_ATTRIBUTE char * +__dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label, + dfsan_label s2_label, dfsan_label n_label, + dfsan_label *ret_label) { + size_t len = strlen(s2); + if (len < n) { + dfsan_memcpy(s1, s2, len+1); + dfsan_memset(s1+len+1, 0, 0, n-len-1); + } else { + dfsan_memcpy(s1, s2, n); + } + + *ret_label = s1_label; + return s1; +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t +__dfsw_pread(int fd, void *buf, size_t count, off_t offset, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, dfsan_label offset_label, + dfsan_label *ret_label) { + ssize_t ret = pread(fd, buf, count, offset); + if (ret > 0) + dfsan_set_label(0, buf, ret); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t +__dfsw_read(int fd, void *buf, size_t count, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, + dfsan_label *ret_label) { + ssize_t ret = read(fd, buf, count); + if (ret > 0) + dfsan_set_label(0, buf, ret); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id, + struct timespec *tp, + dfsan_label clk_id_label, + dfsan_label tp_label, + dfsan_label *ret_label) { + int ret = clock_gettime(clk_id, tp); + if (ret == 0) + dfsan_set_label(0, tp, sizeof(struct timespec)); + *ret_label = 0; + return ret; +} + +static void unpoison(const void *ptr, uptr size) { + dfsan_set_label(0, const_cast(ptr), size); +} + +// dlopen() ultimately calls mmap() down inside the loader, which generally +// doesn't participate in dynamic symbol resolution. Therefore we won't +// intercept its calls to mmap, and we have to hook it here. +SANITIZER_INTERFACE_ATTRIBUTE void * +__dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label, + dfsan_label flag_label, dfsan_label *ret_label) { + void *handle = dlopen(filename, flag); + link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle); + if (map) + ForEachMappedRegion(map, unpoison); + *ret_label = 0; + return handle; +} + +struct pthread_create_info { + void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *); + void *start_routine; + void *arg; +}; + +static void *pthread_create_cb(void *p) { + pthread_create_info pci(*(pthread_create_info *)p); + free(p); + dfsan_label ret_label; + return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0, + &ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create( + pthread_t *thread, const pthread_attr_t *attr, + void *(*start_routine_trampoline)(void *, void *, dfsan_label, + dfsan_label *), + void *start_routine, void *arg, dfsan_label thread_label, + dfsan_label attr_label, dfsan_label start_routine_label, + dfsan_label arg_label, dfsan_label *ret_label) { + pthread_create_info *pci = + (pthread_create_info *)malloc(sizeof(pthread_create_info)); + pci->start_routine_trampoline = start_routine_trampoline; + pci->start_routine = start_routine; + pci->arg = arg; + int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci); + if (rv != 0) + free(pci); + *ret_label = 0; + return rv; +} + +struct dl_iterate_phdr_info { + int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, + size_t size, void *data, dfsan_label info_label, + dfsan_label size_label, dfsan_label data_label, + dfsan_label *ret_label); + void *callback; + void *data; +}; + +int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) { + dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data; + dfsan_set_label(0, *info); + dfsan_set_label(0, const_cast(info->dlpi_name), + strlen(info->dlpi_name) + 1); + dfsan_set_label( + 0, const_cast(reinterpret_cast(info->dlpi_phdr)), + sizeof(*info->dlpi_phdr) * info->dlpi_phnum); + dfsan_label ret_label; + return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0, + 0, &ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr( + int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, + size_t size, void *data, dfsan_label info_label, + dfsan_label size_label, dfsan_label data_label, + dfsan_label *ret_label), + void *callback, void *data, dfsan_label callback_label, + dfsan_label data_label, dfsan_label *ret_label) { + dl_iterate_phdr_info dipi = { callback_trampoline, callback, data }; + *ret_label = 0; + return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label, + dfsan_label buf_label, dfsan_label *ret_label) { + char *ret = ctime_r(timep, buf); + if (ret) { + dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf, + strlen(buf) + 1); + *ret_label = buf_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label, + dfsan_label size_label, dfsan_label stream_label, + dfsan_label *ret_label) { + char *ret = fgets(s, size, stream); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + *ret_label = s_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label, + dfsan_label size_label, dfsan_label *ret_label) { + char *ret = getcwd(buf, size); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + *ret_label = buf_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_get_current_dir_name(dfsan_label *ret_label) { + char *ret = get_current_dir_name(); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label, + dfsan_label len_label, dfsan_label *ret_label) { + int ret = gethostname(name, len); + if (ret == 0) { + dfsan_set_label(0, name, strlen(name) + 1); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getrlimit(int resource, struct rlimit *rlim, + dfsan_label resource_label, dfsan_label rlim_label, + dfsan_label *ret_label) { + int ret = getrlimit(resource, rlim); + if (ret == 0) { + dfsan_set_label(0, rlim, sizeof(struct rlimit)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label, + dfsan_label usage_label, dfsan_label *ret_label) { + int ret = getrusage(who, usage); + if (ret == 0) { + dfsan_set_label(0, usage, sizeof(struct rusage)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label, + dfsan_label src_label, dfsan_label *ret_label) { + char *ret = strcpy(dest, src); // NOLINT + if (ret) { + internal_memcpy(shadow_for(dest), shadow_for(src), + sizeof(dfsan_label) * (strlen(src) + 1)); + } + *ret_label = dst_label; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long int __dfsw_strtol(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + long int ret = strtol(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +double __dfsw_strtod(const char *nptr, char **endptr, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label *ret_label) { + char *tmp_endptr; + double ret = strtod(nptr, &tmp_endptr); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_read_label( + nptr, + tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long long int __dfsw_strtoll(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + long long int ret = strtoll(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + unsigned long int ret = strtoul(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr, + dfsan_label nptr_label, + int base, dfsan_label endptr_label, + dfsan_label base_label, + dfsan_label *ret_label) { + char *tmp_endptr; + long long unsigned int ret = strtoull(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) { + time_t ret = time(t); + if (ret != (time_t) -1 && t) { + dfsan_set_label(0, t, sizeof(time_t)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label, + dfsan_label src_label, dfsan_label dst_label, + dfsan_label *ret_label) { + int ret = inet_pton(af, src, dst); + if (ret == 1) { + dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst, + af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result, + dfsan_label timep_label, dfsan_label result_label, + dfsan_label *ret_label) { + struct tm *ret = localtime_r(timep, result); + if (ret) { + dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result, + sizeof(struct tm)); + *ret_label = result_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd, + char *buf, size_t buflen, struct passwd **result, + dfsan_label uid_label, dfsan_label pwd_label, + dfsan_label buf_label, dfsan_label buflen_label, + dfsan_label result_label, dfsan_label *ret_label) { + // Store the data in pwd, the strings referenced from pwd in buf, and the + // address of pwd in *result. On failure, NULL is stored in *result. + int ret = getpwuid_r(uid, pwd, buf, buflen, result); + if (ret == 0) { + dfsan_set_label(0, pwd, sizeof(struct passwd)); + dfsan_set_label(0, buf, strlen(buf) + 1); + } + *ret_label = 0; + dfsan_set_label(0, result, sizeof(struct passwd*)); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout, + dfsan_label dfs_label, dfsan_label nfds_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = poll(fds, nfds, timeout); + if (ret >= 0) { + for (; nfds > 0; --nfds) { + dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents)); + } + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds, + fd_set *exceptfds, struct timeval *timeout, + dfsan_label nfds_label, dfsan_label readfds_label, + dfsan_label writefds_label, dfsan_label exceptfds_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = select(nfds, readfds, writefds, exceptfds, timeout); + // Clear everything (also on error) since their content is either set or + // undefined. + if (readfds) { + dfsan_set_label(0, readfds, sizeof(fd_set)); + } + if (writefds) { + dfsan_set_label(0, writefds, sizeof(fd_set)); + } + if (exceptfds) { + dfsan_set_label(0, exceptfds, sizeof(fd_set)); + } + dfsan_set_label(0, timeout, sizeof(struct timeval)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask, + dfsan_label pid_label, + dfsan_label cpusetsize_label, + dfsan_label mask_label, dfsan_label *ret_label) { + int ret = sched_getaffinity(pid, cpusetsize, mask); + if (ret == 0) { + dfsan_set_label(0, mask, cpusetsize); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label, + dfsan_label *ret_label) { + int ret = sigemptyset(set); + dfsan_set_label(0, set, sizeof(sigset_t)); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sigaction(int signum, const struct sigaction *act, + struct sigaction *oldact, dfsan_label signum_label, + dfsan_label act_label, dfsan_label oldact_label, + dfsan_label *ret_label) { + int ret = sigaction(signum, act, oldact); + if (oldact) { + dfsan_set_label(0, oldact, sizeof(struct sigaction)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz, + dfsan_label tv_label, dfsan_label tz_label, + dfsan_label *ret_label) { + int ret = gettimeofday(tv, tz); + if (tv) { + dfsan_set_label(0, tv, sizeof(struct timeval)); + } + if (tz) { + dfsan_set_label(0, tz, sizeof(struct timezone)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label n_label, + dfsan_label *ret_label) { + void *ret = memchr(s, c, n); + if (flags().strict_data_dependencies) { + *ret_label = ret ? s_label : 0; + } else { + size_t len = + ret ? reinterpret_cast(ret) - reinterpret_cast(s) + 1 + : n; + *ret_label = + dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label)); + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label *ret_label) { + char *ret = strrchr(s, c); + if (flags().strict_data_dependencies) { + *ret_label = ret ? s_label : 0; + } else { + *ret_label = + dfsan_union(dfsan_read_label(s, strlen(s) + 1), + dfsan_union(s_label, c_label)); + } + + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle, + dfsan_label haystack_label, + dfsan_label needle_label, + dfsan_label *ret_label) { + char *ret = strstr(haystack, needle); + if (flags().strict_data_dependencies) { + *ret_label = ret ? haystack_label : 0; + } else { + size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1; + *ret_label = + dfsan_union(dfsan_read_label(haystack, len), + dfsan_union(dfsan_read_label(needle, strlen(needle) + 1), + dfsan_union(haystack_label, needle_label))); + } + + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req, + struct timespec *rem, + dfsan_label req_label, + dfsan_label rem_label, + dfsan_label *ret_label) { + int ret = nanosleep(req, rem); + *ret_label = 0; + if (ret == -1) { + // Interrupted by a signal, rem is filled with the remaining time. + dfsan_set_label(0, rem, sizeof(struct timespec)); + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_socketpair(int domain, int type, int protocol, int sv[2], + dfsan_label domain_label, dfsan_label type_label, + dfsan_label protocol_label, dfsan_label sv_label, + dfsan_label *ret_label) { + int ret = socketpair(domain, type, protocol, sv); + *ret_label = 0; + if (ret == 0) { + dfsan_set_label(0, sv, sizeof(*sv) * 2); + } + return ret; +} + +// Type of the trampoline function passed to the custom version of +// dfsan_set_write_callback. +typedef void (*write_trampoline_t)( + void *callback, + int fd, const void *buf, ssize_t count, + dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label); + +// Calls to dfsan_set_write_callback() set the values in this struct. +// Calls to the custom version of write() read (and invoke) them. +static struct { + write_trampoline_t write_callback_trampoline = nullptr; + void *write_callback = nullptr; +} write_callback_info; + +SANITIZER_INTERFACE_ATTRIBUTE void +__dfsw_dfsan_set_write_callback( + write_trampoline_t write_callback_trampoline, + void *write_callback, + dfsan_label write_callback_label, + dfsan_label *ret_label) { + write_callback_info.write_callback_trampoline = write_callback_trampoline; + write_callback_info.write_callback = write_callback; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_write(int fd, const void *buf, size_t count, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, dfsan_label *ret_label) { + if (write_callback_info.write_callback) { + write_callback_info.write_callback_trampoline( + write_callback_info.write_callback, + fd, buf, count, + fd_label, buf_label, count_label); + } + + *ret_label = 0; + return write(fd, buf, count); +} +} // namespace __dfsan + +// Type used to extract a dfsan_label with va_arg() +typedef int dfsan_label_va; + +// Formats a chunk either a constant string or a single format directive (e.g., +// '%.3f'). +struct Formatter { + Formatter(char *str_, const char *fmt_, size_t size_) + : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_), + width(-1) {} + + int format() { + char *tmp_fmt = build_format_string(); + int retval = + snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt, + 0 /* used only to avoid warnings */); + free(tmp_fmt); + return retval; + } + + template int format(T arg) { + char *tmp_fmt = build_format_string(); + int retval; + if (width >= 0) { + retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, + tmp_fmt, width, arg); + } else { + retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, + tmp_fmt, arg); + } + free(tmp_fmt); + return retval; + } + + char *build_format_string() { + size_t fmt_size = fmt_cur - fmt_start + 1; + char *new_fmt = (char *)malloc(fmt_size + 1); + assert(new_fmt); + internal_memcpy(new_fmt, fmt_start, fmt_size); + new_fmt[fmt_size] = '\0'; + return new_fmt; + } + + char *str_cur() { return str + str_off; } + + size_t num_written_bytes(int retval) { + if (retval < 0) { + return 0; + } + + size_t num_avail = str_off < size ? size - str_off : 0; + if (num_avail == 0) { + return 0; + } + + size_t num_written = retval; + // A return value of {v,}snprintf of size or more means that the output was + // truncated. + if (num_written >= num_avail) { + num_written -= num_avail; + } + + return num_written; + } + + char *str; + size_t str_off; + size_t size; + const char *fmt_start; + const char *fmt_cur; + int width; +}; + +// Formats the input and propagates the input labels to the output. The output +// is stored in 'str'. 'size' bounds the number of output bytes. 'format' and +// 'ap' are the format string and the list of arguments for formatting. Returns +// the return value vsnprintf would return. +// +// The function tokenizes the format string in chunks representing either a +// constant string or a single format directive (e.g., '%.3f') and formats each +// chunk independently into the output string. This approach allows to figure +// out which bytes of the output string depends on which argument and thus to +// propagate labels more precisely. +// +// WARNING: This implementation does not support conversion specifiers with +// positional arguments. +static int format_buffer(char *str, size_t size, const char *fmt, + dfsan_label *va_labels, dfsan_label *ret_label, + va_list ap) { + Formatter formatter(str, fmt, size); + + while (*formatter.fmt_cur) { + formatter.fmt_start = formatter.fmt_cur; + formatter.width = -1; + int retval = 0; + + if (*formatter.fmt_cur != '%') { + // Ordinary character. Consume all the characters until a '%' or the end + // of the string. + for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%'; + ++formatter.fmt_cur) {} + retval = formatter.format(); + dfsan_set_label(0, formatter.str_cur(), + formatter.num_written_bytes(retval)); + } else { + // Conversion directive. Consume all the characters until a conversion + // specifier or the end of the string. + bool end_fmt = false; + for (; *formatter.fmt_cur && !end_fmt; ) { + switch (*++formatter.fmt_cur) { + case 'd': + case 'i': + case 'o': + case 'u': + case 'x': + case 'X': + switch (*(formatter.fmt_cur - 1)) { + case 'h': + // Also covers the 'hh' case (since the size of the arg is still + // an int). + retval = formatter.format(va_arg(ap, int)); + break; + case 'l': + if (formatter.fmt_cur - formatter.fmt_start >= 2 && + *(formatter.fmt_cur - 2) == 'l') { + retval = formatter.format(va_arg(ap, long long int)); + } else { + retval = formatter.format(va_arg(ap, long int)); + } + break; + case 'q': + retval = formatter.format(va_arg(ap, long long int)); + break; + case 'j': + retval = formatter.format(va_arg(ap, intmax_t)); + break; + case 'z': + case 't': + retval = formatter.format(va_arg(ap, size_t)); + break; + default: + retval = formatter.format(va_arg(ap, int)); + } + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'a': + case 'A': + case 'e': + case 'E': + case 'f': + case 'F': + case 'g': + case 'G': + if (*(formatter.fmt_cur - 1) == 'L') { + retval = formatter.format(va_arg(ap, long double)); + } else { + retval = formatter.format(va_arg(ap, double)); + } + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'c': + retval = formatter.format(va_arg(ap, int)); + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 's': { + char *arg = va_arg(ap, char *); + retval = formatter.format(arg); + va_labels++; + internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg), + sizeof(dfsan_label) * + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + } + + case 'p': + retval = formatter.format(va_arg(ap, void *)); + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'n': { + int *ptr = va_arg(ap, int *); + *ptr = (int)formatter.str_off; + va_labels++; + dfsan_set_label(0, ptr, sizeof(ptr)); + end_fmt = true; + break; + } + + case '%': + retval = formatter.format(); + dfsan_set_label(0, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case '*': + formatter.width = va_arg(ap, int); + va_labels++; + break; + + default: + break; + } + } + } + + if (retval < 0) { + return retval; + } + + formatter.fmt_cur++; + formatter.str_off += retval; + } + + *ret_label = 0; + + // Number of bytes written in total. + return formatter.str_off; +} + +extern "C" { +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, ...) { + va_list ap; + va_start(ap, ret_label); + int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_snprintf(char *str, size_t size, const char *format, + dfsan_label str_label, dfsan_label size_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, ...) { + va_list ap; + va_start(ap, ret_label); + int ret = format_buffer(str, size, format, va_labels, ret_label, ap); + va_end(ap); + return ret; +} + +// Default empty implementations (weak). Users should redefine them. +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *, + u32 *) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {} + +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {} +} // extern "C" diff --git a/lib/dfsan/dfsan_interceptors.cc b/lib/dfsan/dfsan_interceptors.cc deleted file mode 100644 index f4b4babc65c2..000000000000 --- a/lib/dfsan/dfsan_interceptors.cc +++ /dev/null @@ -1,45 +0,0 @@ -//===-- dfsan_interceptors.cc ---------------------------------------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file is a part of DataFlowSanitizer. -// -// Interceptors for standard library functions. -//===----------------------------------------------------------------------===// - -#include "dfsan/dfsan.h" -#include "interception/interception.h" -#include "sanitizer_common/sanitizer_common.h" - -using namespace __sanitizer; - -INTERCEPTOR(void *, mmap, void *addr, SIZE_T length, int prot, int flags, - int fd, OFF_T offset) { - void *res = REAL(mmap)(addr, length, prot, flags, fd, offset); - if (res != (void*)-1) - dfsan_set_label(0, res, RoundUpTo(length, GetPageSize())); - return res; -} - -INTERCEPTOR(void *, mmap64, void *addr, SIZE_T length, int prot, int flags, - int fd, OFF64_T offset) { - void *res = REAL(mmap64)(addr, length, prot, flags, fd, offset); - if (res != (void*)-1) - dfsan_set_label(0, res, RoundUpTo(length, GetPageSize())); - return res; -} - -namespace __dfsan { -void InitializeInterceptors() { - static int inited = 0; - CHECK_EQ(inited, 0); - - INTERCEPT_FUNCTION(mmap); - INTERCEPT_FUNCTION(mmap64); - inited = 1; -} -} // namespace __dfsan diff --git a/lib/dfsan/dfsan_interceptors.cpp b/lib/dfsan/dfsan_interceptors.cpp new file mode 100644 index 000000000000..673171c46f5a --- /dev/null +++ b/lib/dfsan/dfsan_interceptors.cpp @@ -0,0 +1,45 @@ +//===-- dfsan_interceptors.cpp --------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of DataFlowSanitizer. +// +// Interceptors for standard library functions. +//===----------------------------------------------------------------------===// + +#include "dfsan/dfsan.h" +#include "interception/interception.h" +#include "sanitizer_common/sanitizer_common.h" + +using namespace __sanitizer; + +INTERCEPTOR(void *, mmap, void *addr, SIZE_T length, int prot, int flags, + int fd, OFF_T offset) { + void *res = REAL(mmap)(addr, length, prot, flags, fd, offset); + if (res != (void*)-1) + dfsan_set_label(0, res, RoundUpTo(length, GetPageSize())); + return res; +} + +INTERCEPTOR(void *, mmap64, void *addr, SIZE_T length, int prot, int flags, + int fd, OFF64_T offset) { + void *res = REAL(mmap64)(addr, length, prot, flags, fd, offset); + if (res != (void*)-1) + dfsan_set_label(0, res, RoundUpTo(length, GetPageSize())); + return res; +} + +namespace __dfsan { +void InitializeInterceptors() { + static int inited = 0; + CHECK_EQ(inited, 0); + + INTERCEPT_FUNCTION(mmap); + INTERCEPT_FUNCTION(mmap64); + inited = 1; +} +} // namespace __dfsan -- cgit v1.2.3