9 files changed, 188 insertions, 19 deletions

diff --git a/sys/amd64/amd64/elf_machdep.c b/sys/amd64/amd64/elf_machdep.c
index 2f33303e041b..a2d967079ce1 100644
--- a/sys/amd64/amd64/elf_machdep.c
+++ b/sys/amd64/amd64/elf_machdep.c
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/sysent.h>
 #include <sys/imgact_elf.h>
 #include <sys/syscall.h>
+#include <sys/sysent.h>
 #include <sys/signalvar.h>
 #include <sys/vnode.h>
 
@@ -107,6 +108,22 @@ SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
 	(sysinit_cfunc_t) elf64_insert_brand_entry,
 	&freebsd_brand_oinfo);
 
+static Elf64_Brandinfo kfreebsd_brand_info = {
+	.brand		= ELFOSABI_FREEBSD,
+	.machine	= EM_X86_64,
+	.compat_3_brand	= "FreeBSD",
+	.emul_path	= NULL,
+	.interp_path	= "/lib/ld-kfreebsd-x86-64.so.1",
+	.sysvec		= &elf64_freebsd_sysvec,
+	.interp_newpath	= NULL,
+	.brand_note	= &elf64_kfreebsd_brandnote,
+	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
+};
+
+SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_ANY,
+	(sysinit_cfunc_t) elf64_insert_brand_entry,
+	&kfreebsd_brand_info);
+
 
 void
 elf64_dump_thread(struct thread *td __unused, void *dst __unused,
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 8107864e51c7..16f8157e1d4b 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$");
  */
 
 #include "opt_clock.h"
+#include "opt_compat.h"
 #include "opt_cpu.h"
 #include "opt_hwpmc_hooks.h"
 #include "opt_isa.h"
@@ -115,6 +116,13 @@ dtrace_doubletrap_func_t	dtrace_doubletrap_func;
 systrace_probe_func_t	systrace_probe_func;
 #endif
 
+/* Defined in amd64/amd64/elf_machdep.c. */
+extern struct sysentvec elf64_freebsd_sysvec;
+#ifdef COMPAT_IA32
+/* Defined in compat/ia32/ia32_sysvec.c. */
+extern struct sysentvec ia32_freebsd_sysvec;
+#endif
+
 extern void trap(struct trapframe *frame);
 extern void syscall(struct trapframe *frame);
 void dblfault_handler(struct trapframe *frame);
@@ -359,7 +367,13 @@ trap(struct trapframe *frame)
 					 * This check also covers the images
 					 * without the ABI-tag ELF note.
 					 */
-					if (p->p_osrel >= 700004) {
+					if ((curproc->p_sysent ==
+					    &elf64_freebsd_sysvec
+#ifdef COMPAT_IA32
+					    || curproc->p_sysent ==
+					    &ia32_freebsd_sysvec
+#endif
+					    ) && p->p_osrel >= 700004) {
 						i = SIGSEGV;
 						ucode = SEGV_ACCERR;
 					} else {
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index 86d4bbd2bd23..5338da4a848c 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -126,6 +126,7 @@ static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
 static void	exec_linux_setregs(struct thread *td, u_long entry,
 				   u_long stack, u_long ps_strings);
 static void	linux32_fixlimit(struct rlimit *rl, int which);
+static boolean_t linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
 
 static eventhandler_tag linux_exit_tag;
 static eventhandler_tag linux_schedtail_tag;
@@ -1055,14 +1056,38 @@ struct sysentvec elf_linux_sysvec = {
 	.sv_maxssiz	= &linux32_maxssiz,
 };
 
-static char GNULINUX_ABI_VENDOR[] = "GNU";
+static char GNU_ABI_VENDOR[] = "GNU";
+static int GNULINUX_ABI_DESC = 0;
+
+static boolean_t
+linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
+{
+	const Elf32_Word *desc;
+	uintptr_t p;
+
+	p = (uintptr_t)(note + 1);
+	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
+
+	desc = (const Elf32_Word *)p;
+	if (desc[0] != GNULINUX_ABI_DESC)
+		return (FALSE);
+
+	/*
+	 * For linux we encode osrel as follows (see linux_mib.c):
+	 * VVVMMMIII (version, major, minor), see linux_mib.c.
+	 */
+	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
+
+	return (TRUE);
+}
 
 static Elf_Brandnote linux32_brandnote = {
-	.hdr.n_namesz	= sizeof(GNULINUX_ABI_VENDOR),
-	.hdr.n_descsz	= 16,
+	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
+	.hdr.n_descsz	= 16,	/* XXX at least 16 */
 	.hdr.n_type	= 1,
-	.vendor		= GNULINUX_ABI_VENDOR,
-	.flags		= 0
+	.vendor		= GNU_ABI_VENDOR,
+	.flags		= BN_TRANSLATE_OSREL,
+	.trans_osrel	= linux32_trans_osrel
 };
 
 static Elf32_Brandinfo linux_brand = {
diff --git a/sys/compat/ia32/ia32_sysvec.c b/sys/compat/ia32/ia32_sysvec.c
index 644dba6918ee..a44431a79e4a 100644
--- a/sys/compat/ia32/ia32_sysvec.c
+++ b/sys/compat/ia32/ia32_sysvec.c
@@ -171,6 +171,21 @@ SYSINIT(oia32, SI_SUB_EXEC, SI_ORDER_ANY,
 	(sysinit_cfunc_t) elf32_insert_brand_entry,
 	&ia32_brand_oinfo);
 
+static Elf32_Brandinfo kia32_brand_info = {
+	.brand		= ELFOSABI_FREEBSD,
+	.machine	= EM_386,
+	.compat_3_brand	= "FreeBSD",
+	.emul_path	= NULL,
+	.interp_path	= "/lib/ld.so.1",
+	.sysvec		= &ia32_freebsd_sysvec,
+	.brand_note	= &elf32_kfreebsd_brandnote,
+	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
+};
+
+SYSINIT(kia32, SI_SUB_EXEC, SI_ORDER_ANY,
+	(sysinit_cfunc_t) elf32_insert_brand_entry,
+	&kia32_brand_info);
+
 
 void
 elf32_dump_thread(struct thread *td __unused, void *dst __unused,
diff --git a/sys/i386/i386/elf_machdep.c b/sys/i386/i386/elf_machdep.c
index 6df39f7353d9..42779595ff89 100644
--- a/sys/i386/i386/elf_machdep.c
+++ b/sys/i386/i386/elf_machdep.c
@@ -107,6 +107,22 @@ SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
 	(sysinit_cfunc_t) elf32_insert_brand_entry,
 	&freebsd_brand_oinfo);
 
+static Elf32_Brandinfo kfreebsd_brand_info = {
+	.brand		= ELFOSABI_FREEBSD,
+	.machine	= EM_386,
+	.compat_3_brand	= "FreeBSD",
+	.emul_path	= NULL,
+	.interp_path	= "/lib/ld.so.1",
+	.sysvec		= &elf32_freebsd_sysvec,
+	.interp_newpath	= NULL,
+	.brand_note	= &elf32_kfreebsd_brandnote,
+	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
+};
+
+SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY,
+	(sysinit_cfunc_t) elf32_insert_brand_entry,
+	&kfreebsd_brand_info);
+
 
 void
 elf32_dump_thread(struct thread *td __unused, void *dst __unused,
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 3d7633c74e78..fddad06a4e13 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -123,6 +123,9 @@ dtrace_doubletrap_func_t	dtrace_doubletrap_func;
 systrace_probe_func_t	systrace_probe_func;
 #endif
 
+/* Defined in i386/i386/elf_machdep.c. */
+extern struct sysentvec elf32_freebsd_sysvec;
+
 extern void trap(struct trapframe *frame);
 extern void syscall(struct trapframe *frame);
 
@@ -423,7 +426,9 @@ trap(struct trapframe *frame)
 					 * This check also covers the images
 					 * without the ABI-tag ELF note.
 					 */
-					if (p->p_osrel >= 700004) {
+					if (curproc->p_sysent ==
+					    &elf32_freebsd_sysvec &&
+					    p->p_osrel >= 700004) {
 						i = SIGSEGV;
 						ucode = SEGV_ACCERR;
 					} else {
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index 8f43df3a4c66..522b8339ac68 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -107,6 +107,7 @@ static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
 static void	exec_linux_setregs(struct thread *td, u_long entry,
 				   u_long stack, u_long ps_strings);
 static register_t *linux_copyout_strings(struct image_params *imgp);
+static boolean_t linux_trans_osrel(const Elf_Note *note, int32_t *osrel);
 
 static int linux_szplatform;
 const char *linux_platform;
@@ -1025,14 +1026,38 @@ struct sysentvec elf_linux_sysvec = {
 	.sv_maxssiz	= NULL
 };
 
-static char GNULINUX_ABI_VENDOR[] = "GNU";
+static char GNU_ABI_VENDOR[] = "GNU";
+static int GNULINUX_ABI_DESC = 0;
+
+static boolean_t
+linux_trans_osrel(const Elf_Note *note, int32_t *osrel)
+{
+	const Elf32_Word *desc;
+	uintptr_t p;
+
+	p = (uintptr_t)(note + 1);
+	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
+
+	desc = (const Elf32_Word *)p;
+	if (desc[0] != GNULINUX_ABI_DESC)
+		return (FALSE);
+
+	/*
+	 * For linux we encode osrel as follows (see linux_mib.c):
+	 * VVVMMMIII (version, major, minor), see linux_mib.c.
+	 */
+	*osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3];
+
+	return (TRUE);
+}
 
 static Elf_Brandnote linux_brandnote = {
-	.hdr.n_namesz	= sizeof(GNULINUX_ABI_VENDOR),
-	.hdr.n_descsz	= 16,
+	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
+	.hdr.n_descsz	= 16,	/* XXX at least 16 */
 	.hdr.n_type	= 1,
-	.vendor		= GNULINUX_ABI_VENDOR,
-	.flags		= 0
+	.vendor		= GNU_ABI_VENDOR,
+	.flags		= BN_TRANSLATE_OSREL,
+	.trans_osrel	= linux_trans_osrel
 };
 
 static Elf32_Brandinfo linux_brand = {
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 5e6dc0e6f0f8..817a8ee40f46 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -86,6 +86,9 @@ static int __elfN(load_section)(struct vmspace *vmspace, vm_object_t object,
     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
     vm_prot_t prot, size_t pagesize);
 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
+static boolean_t __elfN(freebsd_trans_osrel)(const Elf_Note *note,
+    int32_t *osrel);
+static boolean_t kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel);
 static boolean_t __elfN(check_note)(struct image_params *imgp,
     Elf_Brandnote *checknote, int32_t *osrel);
 
@@ -119,9 +122,56 @@ Elf_Brandnote __elfN(freebsd_brandnote) = {
 	.hdr.n_descsz	= sizeof(int32_t),
 	.hdr.n_type	= 1,
 	.vendor		= FREEBSD_ABI_VENDOR,
-	.flags		= BN_CAN_FETCH_OSREL
+	.flags		= BN_TRANSLATE_OSREL,
+	.trans_osrel	= __elfN(freebsd_trans_osrel)
 };
 
+static boolean_t
+__elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
+{
+	uintptr_t p;
+
+	p = (uintptr_t)(note + 1);
+	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
+	*osrel = *(const int32_t *)(p);
+
+	return (TRUE);
+}
+
+static const char GNU_ABI_VENDOR[] = "GNU";
+static int GNU_KFREEBSD_ABI_DESC = 3;
+
+Elf_Brandnote __elfN(kfreebsd_brandnote) = {
+	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
+	.hdr.n_descsz	= 16,	/* XXX at least 16 */
+	.hdr.n_type	= 1,
+	.vendor		= GNU_ABI_VENDOR,
+	.flags		= BN_TRANSLATE_OSREL,
+	.trans_osrel	= kfreebsd_trans_osrel
+};
+
+static boolean_t
+kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel)
+{
+	const Elf32_Word *desc;
+	uintptr_t p;
+
+	p = (uintptr_t)(note + 1);
+	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
+
+	desc = (const Elf32_Word *)p;
+	if (desc[0] != GNU_KFREEBSD_ABI_DESC)
+		return (FALSE);
+
+	/*
+	 * Debian GNU/kFreeBSD embed the earliest compatible kernel version
+	 * (__FreeBSD_version: <major><two digit minor>Rxx) in the LSB way.
+	 */
+	*osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];
+
+	return (TRUE);
+}
+
 int
 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
 {
@@ -1382,11 +1432,9 @@ __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
 		 * Fetch the osreldate for binary
 		 * from the ELF OSABI-note if necessary.
 		 */
-		if ((checknote->flags & BN_CAN_FETCH_OSREL) != 0 &&
-		    osrel != NULL)
-			*osrel = *(const int32_t *) (note_name +
-			    roundup2(checknote->hdr.n_namesz,
-			    sizeof(Elf32_Addr)));
+		if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
+		    checknote->trans_osrel != NULL)
+			return (checknote->trans_osrel(note, osrel));
 		return (TRUE);
 
 nextnote:
diff --git a/sys/sys/imgact_elf.h b/sys/sys/imgact_elf.h
index c0410cb16416..7a9283946f21 100644
--- a/sys/sys/imgact_elf.h
+++ b/sys/sys/imgact_elf.h
@@ -59,7 +59,10 @@ typedef struct {
 	Elf_Note	hdr;
 	const char *	vendor;
 	int		flags;
-#define	BN_CAN_FETCH_OSREL	0x0001
+	boolean_t	(*trans_osrel)(const Elf_Note *, int32_t *);
+#define	BN_CAN_FETCH_OSREL	0x0001	/* Deprecated. */
+#define	BN_TRANSLATE_OSREL	0x0002	/* Use trans_osrel fetch osrel after */
+					/* checking ABI contraint if needed. */
 } Elf_Brandnote;
 
 typedef struct {
@@ -92,6 +95,7 @@ void	__elfN(dump_thread)(struct thread *, void *, size_t *);
 
 extern	int __elfN(fallback_brand);
 extern Elf_Brandnote __elfN(freebsd_brandnote);
+extern Elf_Brandnote __elfN(kfreebsd_brandnote);
 #endif /* _KERNEL */
 
 #endif /* !_SYS_IMGACT_ELF_H_ */