diff options
Diffstat (limited to 'share/man/man9')
| -rw-r--r-- | share/man/man9/Makefile | 4 | ||||
| -rw-r--r-- | share/man/man9/coredumper_register.9 | 168 | ||||
| -rw-r--r-- | share/man/man9/domainset.9 | 16 | ||||
| -rw-r--r-- | share/man/man9/mbuf.9 | 34 | ||||
| -rw-r--r-- | share/man/man9/style.9 | 160 | ||||
| -rw-r--r-- | share/man/man9/vnode.9 | 4 |
6 files changed, 369 insertions, 17 deletions
diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile index f709a4818dd5..5bcde3030ebc 100644 --- a/share/man/man9/Makefile +++ b/share/man/man9/Makefile @@ -1,5 +1,7 @@ .include <src.opts.mk> +PACKAGE= kernel + MAN= accept_filter.9 \ accf_data.9 \ accf_dns.9 \ @@ -67,6 +69,7 @@ MAN= accept_filter.9 \ config_intrhook.9 \ contigmalloc.9 \ copy.9 \ + coredumper_register.9 \ counter.9 \ cpu_machdep.9 \ cpuset.9 \ @@ -903,6 +906,7 @@ MLINKS+=copy.9 copyin.9 \ copy.9 copyout.9 \ copy.9 copyout_nofault.9 \ copy.9 copystr.9 +MLINKS+=coredumper_register.9 coredumper_unregister.9 MLINKS+=counter.9 counter_u64_alloc.9 \ counter.9 counter_u64_free.9 \ counter.9 counter_u64_add.9 \ diff --git a/share/man/man9/coredumper_register.9 b/share/man/man9/coredumper_register.9 new file mode 100644 index 000000000000..f4c9eb4a1bf6 --- /dev/null +++ b/share/man/man9/coredumper_register.9 @@ -0,0 +1,168 @@ +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.\" Copyright (c) 2025 Kyle Evans <kevans@FreeBSD.org> +.\" +.Dd July 23, 2025 +.Dt COREDUMPER_REGISTER 9 +.Os +.Sh NAME +.Nm coredumper_register , +.Nm coredumper_unregister +.Nd loadable user coredumper support +.Sh SYNOPSIS +.In sys/ucoredump.h +.Ft void +.Fn coredumper_register "struct coredumper *cd" +.Ft void +.Fn coredumper_unregister "struct coredumper *cd" +.Pp +.Ft int +.Fn coredumper_probe_fn "struct thread *td" +.Ft int +.Fn coredumper_handle_fn "struct thread *td" "off_t limit" +.Bd -literal +/* Incomplete, but the useful members are depicted here. */ +struct coredumper { + const char *cd_name; + coredumper_probe_fn *cd_probe; + coredumper_handle_fn *cd_handle; +}; +.Ed +.Pp +.Ft int +.Fn coredump_init_fn "const struct coredump_writer *" \ +"const struct coredump_params *" +.Ft int +.Fn coredump_write_fn "const struct coredump_writer *" "const void *" "size_t" \ +"off_t" "enum uio_seg" "struct ucred *" "size_t *" "struct thread *" +.Ft int +.Fn coredump_extend_fn "const struct coredump_writer *" "off_t" "struct ucred *" +.Bd -literal +struct coredump_writer { + void *ctx; + coredump_init_fn *init_fn; + coredump_write_fn *write_fn; + coredump_extend_fn *extend_fn; +}; +.Ed +.Sh DESCRIPTION +The +.Nm +mechanism provides a path for kernel modules to register a new user process core +dumper. +The expected use of +.Nm +is for a module to define the fields of the struct coredumper listed above, then +call +.Fn coredumper_register +at +.Dv MOD_LOAD +time. +A corresponding +.Fn coredumper_unregister +should be called at +.Dv MOD_UNLOAD +time. +Note that +.Fn coredumper_unregister +will block until the specified coredumper is no longer processing coredumps. +.Pp +When a user process is preparing to start dumping core, the kernel will execute +the +.Fn cd_probe +function for each coredumper currently registered. +The +.Fn cd_probe +function is expected to return either -1 if it would decline to dump the +process, or a priority level greater than 0. +The coredumper with the highest priority will handle the coredump. +The following default priorities are defined: +.Bl -tag -width indent +.It Dv COREDUMPER_NOMATCH +This dumper declines dumping the process. +.It Dv COREDUMPER_GENERIC +This dumper will dump the process at the lowest priority. +This priority is not recommended, as the default vnode dumper will bid at +.Dv COREDUMPER_GENERIC +as well. +.It Dv COREDUMPER_SPECIAL +This dumper provides special behavior, and will dump the process at a higher +priority. +.It Dv COREDUMPER_HIGHPRIORITY +This dumper would prefer to handle this coredump. +This may be used by, for instance, a custom or vendor-specific coredump +mechanism that wishes to preempt others. +.El +.Pp +Note that this system has been designed such that the +.Fn cd_probe +function can examine the process in question and make an informed decision. +Different processes being dumped could probe at different priorities in the +same coredumper. +.Pp +Once the highest priority coredumper has been selected, the +.Fn cd_handle +function will be invoked. +The +.Fn cd_handle +will receive both the thread and the +.Dv RLIMIT_CORE +.Xr setrlimit 2 +.Fa limit . +The proc lock will be held on entry, and should be unlocked before the handler +returns. +The +.Fa limit +is typically passed to the +.Fn sv_coredump +that belongs to the process's +.Va p_sysent . +.Pp +The +.Fn cd_handle +function should return either 0 if the dump was successful, or an appropriate +.Xr errno 2 +otherwise. +.Ss Customized Coredump Writers +Custom coredumpers can define their own +.Dv coredump_writer +to pass to +.Fn sv_coredump . +.Pp +The +.Va ctx +member is opaque and only to be used by the coredumper itself. +.Pp +The +.Va init_fn +function, if it's provided, will be called by the +.Fn sv_coredump +implementation before any data is to be written. +This allows the writer implementation to record any coredump parameters that it +might need to capture, or setup the object to be written to. +.Pp +The +.Va write_fn +function will be called by the +.Fn sv_coredump +implementation to write out data. +The +.Va extend_fn +function will be called to enlarge the coredump, in the sense that a hole is +created in any difference between the current size and the new size. +For convenience, the +.Fn core_vn_write +and +.Fn core_vn_extend +functions used by the vnode coredumper are exposed in +.In sys/ucordumper.h , +and the +.Dv coredump_vnode_ctx +defined there should be populated with the vnode to write to. +.Sh SEE ALSO +.Xr setrlimit 2 , +.Xr core 5 +.Sh AUTHORS +This manual page was written by +.An Kyle Evans Aq Mt kevans@FreeBSD.org . diff --git a/share/man/man9/domainset.9 b/share/man/man9/domainset.9 index 816ce29f04f7..702c9f83a88b 100644 --- a/share/man/man9/domainset.9 +++ b/share/man/man9/domainset.9 @@ -22,7 +22,7 @@ .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" -.Dd April 14, 2021 +.Dd June 24, 2025 .Dt DOMAINSET 9 .Os .Sh NAME @@ -54,6 +54,8 @@ struct domainset { .Ft struct domainset * .Fn domainset_create "const struct domainset *key" .Ft int +.Fn domainset_populate "struct domainset *domain" "domainset_t *mask" "int policy" "size_t mask_size" +.Ft int .Fn sysctl_handle_domainset "SYSCTL_HANDLER_ARGS" .Sh DESCRIPTION The @@ -137,6 +139,7 @@ These policies should be used in preference to to avoid blocking indefinitely on a .Dv M_WAITOK request. +.Pp The .Fn domainset_create function takes a partially filled in domainset as a key and returns a @@ -148,6 +151,17 @@ is an immutable type that is shared among all matching keys and must not be modified after return. .Pp The +.Fn domainset_populate +function fills a +.Vt domainset +struct using a domain mask and policy. +It is used for validating and +translating a domain mask and policy into a +.Vt domainset +struct when creating a custom domainset using +.Vt domainset_create . +.Pp +The .Fn sysctl_handle_domainset function is provided as a convenience for modifying or viewing domainsets that are not accessible via diff --git a/share/man/man9/mbuf.9 b/share/man/man9/mbuf.9 index 0262c598ed18..c05505716a30 100644 --- a/share/man/man9/mbuf.9 +++ b/share/man/man9/mbuf.9 @@ -22,7 +22,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd December 28, 2023 +.Dd July 29, 2025 .Dt MBUF 9 .Os .\" @@ -1091,7 +1091,7 @@ network code, when data must be encrypted or otherwise altered prior to transmission. .El .Sh HARDWARE-ASSISTED CHECKSUM CALCULATION -This section currently applies to TCP/IP only. +This section currently applies to SCTP, TCP, and UDP over IP only. In order to save the host CPU resources, computing checksums is offloaded to the network interface hardware if possible. The @@ -1117,7 +1117,7 @@ in the .Vt mbuf chain containing the packet. .Pp -On output, checksum offloading is attempted after the outgoing +On output, the computation of the checksum is delayed until the outgoing interface has been determined for a packet. The interface-specific field .Va ifnet.if_data.ifi_hwassist @@ -1135,12 +1135,15 @@ such actions will never be requested through .Va csum_flags . .Pp The flags demanding a particular action from an interface are as follows: -.Bl -tag -width ".Dv CSUM_TCP" -offset indent +.Bl -tag -width ".Dv CSUM_SCTP" -offset indent .It Dv CSUM_IP The IP header checksum is to be computed and stored in the corresponding field of the packet. The hardware is expected to know the format of an IP header to determine the offset of the IP checksum field. +.It Dv CSUM_SCTP +The SCTP checksum is to be computed. +(See below.) .It Dv CSUM_TCP The TCP checksum is to be computed. (See below.) @@ -1149,14 +1152,16 @@ The UDP checksum is to be computed. (See below.) .El .Pp -Should a TCP or UDP checksum be offloaded to the hardware, +Should a SCTP, TCP, or UDP checksum be offloaded to the hardware, the field .Va csum_data will contain the byte offset of the checksum field relative to the end of the IP header. -In this case, the checksum field will be initially -set by the TCP/IP module to the checksum of the pseudo header +In the case of TCP or UDP, the checksum field will be initially +set by the TCP or UDP implementation to the checksum of the pseudo header defined by the TCP and UDP specifications. +In the case of SCTP, the checksum field will be initially +set by the SCTP implementation to 0. .Pp On input, an interface indicates the actions it has performed on a packet by setting one or more of the following flags in @@ -1187,13 +1192,13 @@ to obtain the final checksum to be used for TCP or UDP validation purposes. .El .Pp If a particular network interface just indicates success or -failure of TCP or UDP checksum validation without returning +failure of SCTP, TCP, or UDP checksum validation without returning the exact value of the checksum to the host CPU, its driver can mark .Dv CSUM_DATA_VALID -and -.Dv CSUM_PSEUDO_HDR in -.Va csum_flags , +.Va csum_flags +as well as, for TCP and UDP, +.Dv CSUM_PSEUDO_HDR and set .Va csum_data to @@ -1203,6 +1208,13 @@ It is a peculiarity of the algorithm used that the Internet checksum calculated over any valid packet will be .Li 0xFFFF as long as the original checksum field is included. +Note that for SCTP the value of +.Va csum_data +is not relevant and +.Dv CSUM_PSEUDO_HDR +in +.Va csum_flags +is not set, since SCTP does not use a pseudo header checksum. .Sh STRESS TESTING When running a kernel compiled with the option .Dv MBUF_STRESS_TEST , diff --git a/share/man/man9/style.9 b/share/man/man9/style.9 index 484b4f144b2e..e9f17392ae0c 100644 --- a/share/man/man9/style.9 +++ b/share/man/man9/style.9 @@ -22,7 +22,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd March 27, 2025 +.Dd July 28, 2025 .Dt STYLE 9 .Os .Sh NAME @@ -766,8 +766,7 @@ to any pointer type. .Pp Values in .Ic return -statements should be enclosed in parentheses where possible. -For example, parentheses cannot be used if the value is a C++ braced-init-list. +statements should be enclosed in parentheses. .Pp Use .Xr err 3 @@ -918,6 +917,161 @@ Only use the annotation for the entire if statement, rather than individual clauses. Do not add these annotations without empirical evidence of the likelihood of the branch. +.Ss C++ +KNF style was originally defined as a style for C. +C++ introduces several new idioms which do not have an existing corollary +in KNF C such as inline function definitions in classes. +C++ is also not always compatible with some KNF guidelines such as +enclosing return values in parentheses. +For C++ code, FreeBSD aims to follow broadly accepted C++ practices while +also following the general shape of KNF. +This section enumerates C++ specific guidelines that differ from KNF C. +.Pp +The preferred suffixes for C++ source files are +.Dq .cc +and +.Dq .hh . +Header files should always use a suffix, +unlike headers from the C++ standard library. +.Pp +Return values should not be enclosed in parantheses. +When converting existing C code to C++, +existing return values may remain in parantheses. +.Pp +The opening curly brace for namespace declarations should be on the first line +similar to structure and class definitions. +Nested namespaces should be declared using a single namespace declaration. +.Bd -literal +namespace foo::bar { +} +.Ed +.Pp +Member function declarations should follow the same style used for standalone +function protoypes except that a space should be used between a function's +return type and name. +.Pp +Function definitions at the top level should use a newline after the function +type similar to C function definitions. +.Pp +Nested member function definitions inside of a class, structure, or union +should not use a newline after the function type. +Instead, these should follow the style of member function declarations. +This is more common C++ style and is more compact for small methods such as +getters and setters. +.Pp +Inline functions whose body consists of a single statement may use a single +line for the function body. +Inline functions with an empty body should always use a single line. +.Bd -literal +struct widget { + int foo() { return 4; } + int bar(); +}; + +int +widget::bar() +{ + return 6; +} +.Ed +.Pp +Default and deleted methods should be declared as a single line. +.Bd -literal +class box { + ~box() = default; +}; +.Ed +.Pp +In template declarations, the +.Ic template +keyword and list of template parameters should be followed by a newline +before the templated declaration. +.Bd -literal +template <typename T> +class box { + T data; +}; +.Ed +.Pp +The +.Ic & +for reference variables should be placed on the variable name rather +than the type similar to the style used with +.Ic * +for pointers. +.Bd -literal + int x; + int &xp = x; +.Ed +.Pp +Variables may be declared at any point within a function, +not just at the start of blocks. +.Pp +Standard library containers should be used in preference to +.Xr queue 3 +or +.Xr tree 3 +macros. +.Pp +.Ic nullptr +should be used instead of +.Dv NULL +or 0. +.Pp +Use standard library types for managing strings such as +.Vt std::string +and +.Vt std::string_view +rather than +.Vt "char *" +and +.Vt "const char *" . +C types may be used when interfacing with C code. +.Pp +The +.Ic auto +keyword can be used in various contexts which improve readability. +Examples include iterators, non-trivial types of ranged-for values, +and return values of obvious types, +such as +.Ic static_cast +or +.Fn std::make_unique . +Place any qualifiers before +.Ic auto , +for example: +.Ic const auto . +.Pp +Use the +.Vt std::unique_ptr +and +.Vt std::shared_ptr +smart pointers to manage the lifetime of dynamically allocated objects +instead of +.Ic new +and +.Ic delete . +Construct smart pointers with +.Fn std::make_unique +or +.Fn std::make_shared . +Do not use +.Xr malloc 3 +except when necessary to interface with C code. +.Pp +Do not import any namespaces with +.Ic using +at global scope in header files. +Namespaces other than the +.Ic std +namespace (for example, +.Ic std::literals ) +may be imported in source files and in function scope in header files. +.Pp +Define type aliases using +.Ic using +instead of +.Ic typedef . .Sh FILES .Bl -tag -width indent .It Pa /usr/src/tools/build/checkstyle9.pl diff --git a/share/man/man9/vnode.9 b/share/man/man9/vnode.9 index 5dd087725e92..d17492668298 100644 --- a/share/man/man9/vnode.9 +++ b/share/man/man9/vnode.9 @@ -24,7 +24,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.Dd October 9, 2024 +.Dd July 15, 2025 .Dt VNODE 9 .Os .Sh NAME @@ -113,7 +113,7 @@ The function declarations and definitions are generated from .Pa sys/kern/vnode_if.src by the -.Pa sys/tools/vndoe_if.awk +.Pa sys/tools/vnode_if.awk script. The interfaces are documented in their respective manual pages like .Xr VOP_READ 9 |