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authorDmitry V. Levin <ldv@altlinux.org>2015-12-27 16:30:02 +0000
committerDmitry V. Levin <ldv@altlinux.org>2015-12-31 00:17:48 +0000
commite0043e17dfc52fe1702746543127cb4a87232bcd (patch)
tree73e7287e78b9775e8a4c603136fbf6c6fa1a5451 /sysdeps/unix/sysv/linux/tst-personality.c
parentcc42170ef6ca931c7527a86f14fc66059b6dfff4 (diff)
downloadglibc-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.c45
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"