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author | Dmitry V. Levin <ldv@altlinux.org> | 2015-12-27 16:30:02 +0000 |
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committer | Dmitry V. Levin <ldv@altlinux.org> | 2015-12-31 00:17:48 +0000 |
commit | e0043e17dfc52fe1702746543127cb4a87232bcd (patch) | |
tree | 73e7287e78b9775e8a4c603136fbf6c6fa1a5451 /sysdeps/unix/sysv/linux/tst-personality.c | |
parent | cc42170ef6ca931c7527a86f14fc66059b6dfff4 (diff) | |
download | glibc-e0043e17dfc52fe1702746543127cb4a87232bcd.tar.gz |
Fix linux personality syscall wrapper
The personality system call, starting with linux kernel commit
v2.6.29-6609-g11d06b2a1e5658f448a308aa3beb97bacd64a940, always
successfully changes the personality if requested. The syscall
wrapper, however, still can return an error in the following cases:
- the value returned by the system call looks like an error
due to architecture limitations of 32-bit kernels;
- a personality greater than 0xffffffff is passed to the system call,
and the 64-bit kernel does not have commit
v2.6.35-rc1-372-g485d527686850d68a0e9006dd9904f19f122485e
that would truncate this value to unsigned int;
- on sparc64, the value returned by the system call looks like an error
due to sparc64 kernel sign extension bug.
The solution is three-fold:
- move generic syscalls.list personality entry to generic 64-bit
syscalls.list file;
- for each 32-bit architecture that use negated errno semantics,
add a NOERRNO personality entry to their syscalls.list file;
- for sparc64 and 32-bit architectures that use dedicated registers
to flag syscall errors, add a wrapper around personality syscall;
if the system call return value is flagged as an error, this wrapper
returns the negated "would be errno" value, otherwise it returns
the system call return value; on sparc64, it also truncates the
personality argument to unsigned int before passing it to the kernel.
[BZ #19408]
* sysdeps/unix/sysv/linux/personality.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc64/personality.c: Likewise.
* sysdeps/unix/sysv/linux/tst-personality.c: Likewise.
* sysdeps/unix/sysv/linux/Makefile [$(subdir) == misc]
(sysdep_routines): Add personality.
(tests): Add tst-personality.
* sysdeps/unix/sysv/linux/syscalls.list (personality): Move ...
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: ... here.
* sysdeps/unix/sysv/linux/arm/syscalls.list (personality): New entry.
* sysdeps/unix/sysv/linux/hppa/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/i386/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/m68k/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/microblaze/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/syscalls.list (personality):
Likewise.
* sysdeps/unix/sysv/linux/sh/syscalls.list (personality): Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/syscalls.list (personality):
Likewise.
Diffstat (limited to 'sysdeps/unix/sysv/linux/tst-personality.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/tst-personality.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/tst-personality.c b/sysdeps/unix/sysv/linux/tst-personality.c new file mode 100644 index 0000000000..1bfa5029df --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-personality.c @@ -0,0 +1,45 @@ +/* BZ #19408 linux personality syscall wrapper test. + + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <sys/personality.h> + +static int +do_test (void) +{ + int rc = 0; + unsigned int test_persona = -EINVAL; + unsigned int saved_persona; + + errno = 0xdefaced; + saved_persona = personality (0xffffffff); + + if (personality (test_persona) != saved_persona || + personality (0xffffffff) == -1 || + personality (PER_LINUX) == -1 || + personality (0xffffffff) != PER_LINUX || + 0xdefaced != errno) + rc = 1; + + (void) personality (saved_persona); + return rc; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" |