diff options
Diffstat (limited to 'lib/libc/sys')
| -rw-r--r-- | lib/libc/sys/ptrace.2 | 66 |
1 files changed, 65 insertions, 1 deletions
diff --git a/lib/libc/sys/ptrace.2 b/lib/libc/sys/ptrace.2 index 8e9c5d8ab87a..6148e6d333d5 100644 --- a/lib/libc/sys/ptrace.2 +++ b/lib/libc/sys/ptrace.2 @@ -2,7 +2,7 @@ .\" $NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $ .\" .\" This file is in the public domain. -.Dd July 15, 2019 +.Dd April 10, 2021 .Dt PTRACE 2 .Os .Sh NAME @@ -807,6 +807,70 @@ and extends up to The .Fa data argument is ignored. +.It Dv PT_COREDUMP +This request creates a coredump for the stopped program. +The +.Fa addr +argument specifies a pointer to a +.Vt "struct ptrace_coredump" , +which is defined as follows: +.Bd -literal +struct ptrace_coredump { + int pc_fd; + uint32_t pc_flags; + off_t pc_limit; +}; +.Ed +The fields of the structure are: +.Bl -tag -width pc_flags +.It Dv pc_fd +File descriptor to write the dump to. +It must refer to a regular file, opened for writing. +.It Dv pc_flags +Flags. +The following flags are defined: +.Bl -tag -width PC_COMPRESS +.It Dv PC_COMPRESS +Request compression of the dump. +.It Dv PC_ALL +Include non-dumpable entries into the dump. +The dumper ignores +.Dv MAP_NOCORE +flag of the process map entry, but device mappings are not dumped even with +.Dv PC_ALL +set. +.El +.It Dv pc_limit +Maximum size of the coredump. +Specify zero for no limit. +.El +.Pp +The size of +.Vt "struct ptrace_coredump" +must be passed in +.Fa data . +.Pp +The process must be stopped before dumping core. +A single thread in the target process is temporarily unsuspended +in kernel to write the dump. +If the +.Nm +call fails before a thread is unsuspended, there is no event to +.Xr waitpid 2 +for. +If a thread was unsuspended, it will stop again before the +.Nm +call returns, and the process must be waited upon using +.Xr waitpid 2 +to consume the new stop event. +Since it is hard to deduce whether a thread was unsuspended before +an error occurred, it is recommended to unconditionally perform +.Xr waitpid 2 +with +.Dv WNOHANG +flag after +.Dv PT_COREDUMP , +and silently accept zero result from it. .El .Sh ARM MACHINE-SPECIFIC REQUESTS .Bl -tag -width "Dv PT_SETVFPREGS" |