https://github.com/torvalds/linux
Revision c90e6fbb220d44988cb65af3707367c57cdb65a8 authored by Dmitry Adamushko on 05 April 2012, 18:37:34 UTC, committed by Ralf Baechle on 05 December 2012, 18:59:00 UTC
The problem occurs [1] when a kernel-mode task returns from a system call with a pending signal. A real-life scenario is a child of 'khelper' returning from a failed kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ]. kernel_execve() fails due to a pending SIGKILL, which is the result of "kill -9 -1" (at least, busybox's init does it upon reboot). The loop is as follows: * syscall_exit_work: - work_pending: // start_of_the_loop - work_notifysig: - do_notify_resume() - do_signal() - if (!user_mode(regs)) return; - resume_userspace // TIF_SIGPENDING is still set - work_pending // so we call work_pending => goto // start_of_the_loop More information can be found in another LKML thread: http://www.serverphorums.com/read.php?12,457826 [1] The problem was also reproduced on !CONFIG_VM86 x86, and the following fix was accepted. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74f Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3571/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Tip revision: c90e6fbb220d44988cb65af3707367c57cdb65a8 authored by Dmitry Adamushko on 05 April 2012, 18:37:34 UTC
MIPS: Fix endless loop when processing signals for kernel tasks
MIPS: Fix endless loop when processing signals for kernel tasks
Tip revision: c90e6fb
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1.1 KB |
.mailmap | -rw-r--r-- | 4.4 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 92.8 KB |
Kbuild | -rw-r--r-- | 2.5 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 224.8 KB |
Makefile | -rw-r--r-- | 46.6 KB |
README | -rw-r--r-- | 18.2 KB |
REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
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