diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-20 20:43:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:17:03 +0300 |
| commit | 8f072ec8b41b783ceb98e9893896a73e7f746de8 (patch) | |
| tree | 4456e737d0e4ec6b135448611d11763c10ebd054 /arch/sh | |
| parent | 671dd8b385b29d7813f03bde85315c46264dbd23 (diff) | |
| download | linux-8f072ec8b41b783ceb98e9893896a73e7f746de8.tar.xz | |
signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL)
[ Upstream commit ce0ee4e6ac99606f3945f4d47775544edc3f7985 ]
Today the sh code allocates memory the first time a process uses
the fpu. If that memory allocation fails, kill the affected task
with force_sig(SIGKILL) rather than do_group_exit(SIGKILL).
Calling do_group_exit from an exception handler can potentially lead
to dead locks as do_group_exit is not designed to be called from
interrupt context. Instead use force_sig(SIGKILL) to kill the
userspace process. Sending signals in general and force_sig in
particular has been tested from interrupt context so there should be
no problems.
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Fixes: 0ea820cf9bf5 ("sh: Move over to dynamically allocated FPU context.")
Link: https://lkml.kernel.org/r/20211020174406.17889-6-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/sh')
| -rw-r--r-- | arch/sh/kernel/cpu/fpu.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/sh/kernel/cpu/fpu.c b/arch/sh/kernel/cpu/fpu.c index ae354a2931e7..fd6db0ab1928 100644 --- a/arch/sh/kernel/cpu/fpu.c +++ b/arch/sh/kernel/cpu/fpu.c @@ -62,18 +62,20 @@ void fpu_state_restore(struct pt_regs *regs) } if (!tsk_used_math(tsk)) { - local_irq_enable(); + int ret; /* * does a slab alloc which can sleep */ - if (init_fpu(tsk)) { + local_irq_enable(); + ret = init_fpu(tsk); + local_irq_disable(); + if (ret) { /* * ran out of memory! */ - do_group_exit(SIGKILL); + force_sig(SIGKILL); return; } - local_irq_disable(); } grab_fpu(regs); |