x86/fault: Don't send SIGSEGV twice on SEGV_PKUERR

__bad_area_nosemaphore() calls both force_sig_pkuerr() and
force_sig_fault() when handling SEGV_PKUERR. This does not cause
problems because the second signal is filtered by the legacy_queue()
check in __send_signal() because in both cases, the signal is SIGSEGV,
the second one seeing that the first one is already pending.

This causes the kernel to do unnecessary work so send the signal only
once for SEGV_PKUERR.

 [ bp: Massage commit message. ]

Fixes: 9db812dbb29d ("signal/x86: Call force_sig_pkuerr from __bad_area_nosemaphore")
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jiashuo Liang <liangjs@pku.edu.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lkml.kernel.org/r/20210601085203.40214-1-liangjs@pku.edu.cn
This commit is contained in:
Jiashuo Liang 2021-06-01 16:52:03 +08:00 committed by Borislav Petkov
parent f1d4d47c58
commit 5405b42c2f

View File

@ -836,8 +836,8 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
if (si_code == SEGV_PKUERR)
force_sig_pkuerr((void __user *)address, pkey);
force_sig_fault(SIGSEGV, si_code, (void __user *)address);
else
force_sig_fault(SIGSEGV, si_code, (void __user *)address);
local_irq_disable();
}