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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2012-04-16 10:31:09 +1200 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2012-04-17 23:09:04 +1200 |
| commit | 69287cb678589ee38ac5fc99708d83a84cd0ae7b (patch) | |
| tree | 2a29805fd1195ca44dfa5b8f14367c1402e0a5f8 | |
| parent | 3612be04180185f3cf02fba33d470ff07e4187a2 (diff) | |
| download | man-pages-69287cb678589ee38ac5fc99708d83a84cd0ae7b.tar.gz | |
prctl.2: Fixes to PR_SET_MM after comments from Cyrill
Remove some FIXMEs and comment out pieces of text that describe
features not yet merged mainline kernel.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
| -rw-r--r-- | man2/prctl.2 | 198 |
1 files changed, 96 insertions, 102 deletions
diff --git a/man2/prctl.2 b/man2/prctl.2 index e6d4ccc836..c8979e3f6e 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -434,11 +434,8 @@ The corresponding memory area must be readable and writable. Set the address above which the program heap can be expanded with .BR brk (2) call. -.\" FIXME In the next sentence, shouldn't "not be greater" be "be greater"? -The address must not be greater than the ending address of +The address must be greater than the ending address of the current program data segment. -.\" FIXME I completely rewrote the following sentence. Is it okay? -.\" FIXME Is the following error documented in ERRORS? In addition, the combined size of the resulting heap and the size of the data segment can't exceed the .BR RLIMIT_DATA @@ -452,67 +449,66 @@ value. The requirements for the address are the same as for the .BR PR_SET_MM_START_BRK option. -.\" FIXME Delete or comment out the following? (until ========) -.\" None of the following constants exist in current kernel source -.\" What is the state of the kernel patches for these? -.TP -.BR PR_SET_MM_ARG_START -Set the address above which the program command line is placed. -.TP -.BR PR_SET_MM_ARG_END -Set the address below which the program command line is placed. -.TP -.BR PR_SET_MM_ENV_START -Set the address above which the program environment is placed. -.TP -.BR PR_SET_MM_ENV_END -Set the address below which the program environment is placed. -.IP -The address passed with -.BR PR_SET_MM_ARG_START , -.BR PR_SET_MM_ARG_END , -.BR PR_SET_MM_ENV_START , -and -.BR PR_SET_MM_ENV_END -should belong to a process stack area. -Thus, the corresponding memory area must be readable, writable, and -(depending on the kernel configuration) have the -.BR MAP_GROWSDOWN -attribute set (see -.BR mmap (2)). -.TP -.BR PR_SET_MM_AUXV -Set a new auxiliary vector. -The -.I arg3 -argument should provide the address of the vector. -The -.I arg4 -is the size of the vector. -.TP -.BR PR_SET_MM_EXE_FILE -Supersede the -.IR /proc/pid/exe -symbolic link with a new one pointing to a new executable file -identified by the file descriptor provided in -.I arg3 -argument. -The file descriptor should be obtained with a regular -.BR open (2) -call. -.IP -To change the symbolic link, one needs to unmap all existing -executable memory areas, including those created by the kernel itself -(for example the kernel usually creates at least one executable -memory area for the ELF -.IR \.text -section). -.IP -The second limitation is that such transitions can be done only once -in a process life time. -Any further attempts will be rejected. -This should help system administrators to monitor the unusual -symbolic-link transitions over all process running in a system. +.\" FIXME The following (until ========) is not yet in mainline kernel, +.\" so commented out for the moment. +.\" .TP +.\" .BR PR_SET_MM_ARG_START +.\" Set the address above which the program command line is placed. +.\" .TP +.\" .BR PR_SET_MM_ARG_END +.\" Set the address below which the program command line is placed. +.\" .TP +.\" .BR PR_SET_MM_ENV_START +.\" Set the address above which the program environment is placed. +.\" .TP +.\" .BR PR_SET_MM_ENV_END +.\" Set the address below which the program environment is placed. +.\" .IP +.\" The address passed with +.\" .BR PR_SET_MM_ARG_START , +.\" .BR PR_SET_MM_ARG_END , +.\" .BR PR_SET_MM_ENV_START , +.\" and +.\" .BR PR_SET_MM_ENV_END +.\" should belong to a process stack area. +.\" Thus, the corresponding memory area must be readable, writable, and +.\" (depending on the kernel configuration) have the +.\" .BR MAP_GROWSDOWN +.\" attribute set (see +.\" .BR mmap (2)). +.\" .TP +.\" .BR PR_SET_MM_AUXV +.\" Set a new auxiliary vector. +.\" The +.\" .I arg3 +.\" argument should provide the address of the vector. +.\" The +.\" .I arg4 +.\" is the size of the vector. +.\" .TP +.\" .BR PR_SET_MM_EXE_FILE +.\" Supersede the +.\" .IR /proc/pid/exe +.\" symbolic link with a new one pointing to a new executable file +.\" identified by the file descriptor provided in +.\" .I arg3 +.\" argument. +.\" The file descriptor should be obtained with a regular +.\" .BR open (2) +.\" call. +.\" .IP +.\" To change the symbolic link, one needs to unmap all existing +.\" executable memory areas, including those created by the kernel itself +.\" (for example the kernel usually creates at least one executable +.\" memory area for the ELF +.\" .IR \.text +.\" section). +.\" .IP +.\" The second limitation is that such transitions can be done only once +.\" in a process life time. +.\" Any further attempts will be rejected. +.\" This should help system administrators to monitor unusual +.\" symbolic-link transitions over all process running in a system. .\" ========== END FIXME .RE .\" @@ -569,7 +565,6 @@ or .BR PR_SET_SECCOMP , and the kernel was not configured with .BR CONFIG_SECCOMP . -.\" FIXME I added the following lengthy EINVAL entry. Is it correct? .TP .B EINVAL .I option @@ -605,7 +600,6 @@ or .BR PR_SET_MM_BRK , and .I arg3 -.\" FIXME Is the following correct (see earlier comment) is less than or equal to the end of the data segment or specifies a value that would cause the .B RLIMIT_DATA @@ -649,41 +643,41 @@ is and the caller does not have the .B CAP_SYS_RESOURCE capability. -.TP -.B EACCES -.I option -is -.BR PR_SET_MM , -and -.I arg3 -is -.\" FIXME PR_SET_MM_EXE_FILE is not in the kernel sources -.BR PR_SET_MM_EXE_FILE , -the file is not executable. -.TP -.B EBUSY -.I option -is -.BR PR_SET_MM , -.I arg3 -is -.\" FIXME PR_SET_MM_EXE_FILE is not in the kernel sources -.BR PR_SET_MM_EXE_FILE , -and this the second attempt to change the -.I /proc/pid/exe -symbolic link, which is prohibited. -.TP -.B EBADF -.I option -is -.BR PR_SET_MM , -.I arg3 -is -.\" FIXME PR_SET_MM_EXE_FILE is not in the kernel sources -.BR PR_SET_MM_EXE_FILE , -and the file descriptor passed in -.I arg4 -is not valid. +.\" FIXME The following (until ========) is not yet in mainline kernel, +.\" so commented out for the moment. +.\" .TP +.\" .B EACCES +.\" .I option +.\" is +.\" .BR PR_SET_MM , +.\" and +.\" .I arg3 +.\" is +.\" .BR PR_SET_MM_EXE_FILE , +.\" the file is not executable. +.\" .TP +.\" .B EBUSY +.\" .I option +.\" is +.\" .BR PR_SET_MM , +.\" .I arg3 +.\" is +.\" .BR PR_SET_MM_EXE_FILE , +.\" and this the second attempt to change the +.\" .I /proc/pid/exe +.\" symbolic link, which is prohibited. +.\" .TP +.\" .B EBADF +.\" .I option +.\" is +.\" .BR PR_SET_MM , +.\" .I arg3 +.\" is +.\" .BR PR_SET_MM_EXE_FILE , +.\" and the file descriptor passed in +.\" .I arg4 +.\" is not valid. +.\" ========== END FIXME .\" The following can't actually happen, because prctl() in .\" seccomp mode will cause SIGKILL. .\" .TP |