See https://bugzilla.kernel.org/show_bug.cgi?id=137351
Reported-by: Laurent Georget <laurent.georget@supelec.fr>
Reported-by: Ivan Kharpalev <ivan.kharpalev@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
As reported by Chris:i
The manual entry for KDGETMODE specifies "argp points to
a long which is set to one of the above values." At least
on x86_64-bit Fedora24, the text should probably specify
argp is an int (32-bit), rather than a long (64-bit).
[To verify:]
Open a file descriptor to the local console, and execute
some code like the following:
long arg = -1;
if (-1 == ioctl(fd, KDGETMODE, &arg)) { return -1; }
printf("KDGETMODE: 0x%lx\n", arg);
Now try this version:
int arg = -1;
if (-1 == ioctl(fd, KDGETMODE, &arg)) { return -1; }
printf("KDGETMODE: 0x%x\n", arg);
Result:
The first version gives this result:
KDGETMODE: 0xffffffff00000001
The second version gives this result:
KDGETMODE: 0x1
Reading the kernel source confirms this point.
Reported-by: Chris Gassib <position0x45@hotmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The getauxval(3) man page describes the result for AT_HWCAP as
"A pointer to a multibyte mask of bits", however the actual value
returned is not a pointer, but simply the first 32 bits of the
capabilities mask.
This can be observed directly. Note the value shown for AT_HWCAP
is a 32 bit value that is not a pointer (see AT_PHDR or AT_RANDOM
for how pointers are shown).
% LD_SHOW_AUXV=1 cat < /dev/null
AT_SYSINFO_EHDR: 0x7fffe89fe000
AT_HWCAP: bfebfbff
AT_PAGESZ: 4096
AT_CLKTCK: 100
AT_PHDR: 0x400040
AT_PHENT: 56
AT_PHNUM: 9
AT_BASE: 0x0
AT_FLAGS: 0x0
AT_ENTRY: 0x402634
AT_UID: 515
AT_EUID: 515
AT_GID: 114
AT_EGID: 114
AT_SECURE: 0
AT_RANDOM: 0x7fffe8917be9
AT_EXECFN: /usr/bin/cat
AT_PLATFORM: x86_64
With respect to cgroups version 1, CAP_SYS_ADMIN in the user
namespace allows only *named* hierarchies to be mounted (and
not hierarchies that have a controller).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
strxfrm() and strncpy() are not precisely equivalent in the
POSIX locale, so this NOTES section was not really correct.
See https://bugzilla.kernel.org/show_bug.cgi?id=104221
Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add some more details for Section 1 and 8 formatting.
Separate out formatting discussion into commands, functions,
and "general".
In part triggered by https://bugzilla.kernel.org/show_bug.cgi?id=121211
Reported-by: Josh Triplett <josh@kernel.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The perf_output_sample_ustack in kernel/events/core.c only writes
a single 64 bit word if it can't dump the user registers. From the
current version of the man page, I would have expected two 64 bit
words (one for size, one for dyn_size). Change the man page to
make this behavior explicit.
Reviewed-by: Vince Weaver <vincent.weaver@maine.edu>
The license on the original versoin of this page is troublesome,
because of restrictions imposed by the clause that the page may be
modified "for the purpose of improving Linux or its documentation
efforts".
By now, I have rewritten all except trivial pieces of the page,
and the structure definitions in any case came from kernel header
files. So, I'm relicensing the page to the "verbatim" license.
See https://bugzilla.kernel.org/show_bug.cgi?id=118311
Reported-by: Tom Callaway <tcallawa@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Niki Rahimi, the author of this page, has agreed that it's okay
to change the license to note that the page can be modified.
See https://bugzilla.kernel.org/show_bug.cgi?id=118311
Reported-by: Tom Callaway <tcallawa@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>