Blackfin arch: fix signal handling bug - linux-dev - Linux kernel development work

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author	Bernd Schmidt <bernd.schmidt@analog.com>	2007-05-21 18:09:33 +0800
committer	Linus Torvalds <torvalds@woody.linux-foundation.org>	2007-05-21 09:50:23 -0700
commit	c824498db47285aeff430c007685a193b673c949 (patch)
tree	685e3736b978199da0588ad14b7e24ee2b7c8d0a /include/linux/sysdev.h
parent	Blackfin arch: cache SWRST value at bootup so other things like watchdog can non-destructively query it (diff)

Blackfin arch: fix signal handling bug

There's a forum thread at https://blackfin.uclinux.org/gf/project/uclinux-dist/forum/?action=ForumBrowse&_forum_action=MessageReply&message_id=24741 which has a testcase involving signal handling that crashes quite readily. Inspecting the code I believe what happens is that signal handling can become confused when it is invoked on return from an interrupt, if the contents of P0 and R0 at the time of the interrupt happen to be such that P0 is larger than zero (indicating to the signal code that we're in a syscall), and R0 happens to have a value of something like -EINTR or -ERESTARTSYS. Fixed by setting orig_p0 to -1 if we're returning from an interrupt. The testcase now seems to run without problems. Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Diffstat (limited to 'include/linux/sysdev.h')

0 files changed, 0 insertions, 0 deletions

/* Copyright (C) 2003-2013 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2003. 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 <alloca.h> #include <errno.h> #include <pthreadP.h> #include <sysdep.h> #include <sys/types.h> #include <shlib-compat.h> size_t __kernel_cpumask_size attribute_hidden; /* Determine the current affinity. As a side affect we learn about the size of the cpumask_t in the kernel. */ int __determine_cpumask_size (pid_t tid) { INTERNAL_SYSCALL_DECL (err); int res; size_t psize = 128; void *p = alloca (psize); while (res = INTERNAL_SYSCALL (sched_getaffinity, err, 3, tid, psize, p), INTERNAL_SYSCALL_ERROR_P (res, err) && INTERNAL_SYSCALL_ERRNO (res, err) == EINVAL) p = extend_alloca (p, psize, 2 * psize); if (res == 0 || INTERNAL_SYSCALL_ERROR_P (res, err)) return INTERNAL_SYSCALL_ERRNO (res, err); __kernel_cpumask_size = res; return 0; } int __pthread_setaffinity_new (pthread_t th, size_t cpusetsize, const cpu_set_t *cpuset) { const struct pthread *pd = (const struct pthread *) th; INTERNAL_SYSCALL_DECL (err); int res; if (__builtin_expect (__kernel_cpumask_size == 0, 0)) { res = __determine_cpumask_size (pd->tid); if (res != 0) return res; } /* We now know the size of the kernel cpumask_t. Make sure the user does not request to set a bit beyond that. */ for (size_t cnt = __kernel_cpumask_size; cnt < cpusetsize; ++cnt) if (((char *) cpuset)[cnt] != '\0') /* Found a nonzero byte. This means the user request cannot be fulfilled. */ return EINVAL; res = INTERNAL_SYSCALL (sched_setaffinity, err, 3, pd->tid, cpusetsize, cpuset); #ifdef RESET_VGETCPU_CACHE if (!INTERNAL_SYSCALL_ERROR_P (res, err)) RESET_VGETCPU_CACHE (); #endif return (INTERNAL_SYSCALL_ERROR_P (res, err) ? INTERNAL_SYSCALL_ERRNO (res, err) : 0); } versioned_symbol (libpthread, __pthread_setaffinity_new, pthread_setaffinity_np, GLIBC_2_3_4); #if SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_3_4) int __pthread_setaffinity_old (pthread_t th, cpu_set_t *cpuset) { /* The old interface by default assumed a 1024 processor bitmap. */ return __pthread_setaffinity_new (th, 128, cpuset); } compat_symbol (libpthread, __pthread_setaffinity_old, pthread_setaffinity_np, GLIBC_2_3_3); #endif


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