diff options
| author |   Stas Sergeev <stsp@list.ru> | 2016-04-14 23:20:02 +0300 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-05-03 08:37:58 +0200 |
| commit | 0b4521e8cf1f582da3045ea460427ac2f741578f (patch) | |
| tree | 6e3df731220a263c3bf5846652c799fb3d7631a2 /arch/x86/kernel/signal.c | |
| parent | Linux 4.6-rc6 (diff) | |
| download | linux-dev-0b4521e8cf1f582da3045ea460427ac2f741578f.tar.xz linux-dev-0b4521e8cf1f582da3045ea460427ac2f741578f.zip | |
signals/sigaltstack, x86/signals: Unify the x86 sigaltstack check with other architectures
Currently x86's get_sigframe() checks for "current->sas_ss_size"
to determine whether there is a need to switch to sigaltstack.
The common practice used by all other arches is to check for
sas_ss_flags(sp) == 0
This patch makes the code consistent with other architectures.
The slight complexity of the patch is added by the optimization on
!sigstack check that was requested by Andy Lutomirski: sas_ss_flags(sp)==0
already implies that we are not on a sigstack, so the code is shuffled
to avoid the duplicate checking.
This patch should have no user-visible impact.
Signed-off-by: Stas Sergeev <stsp@list.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1460665206-13646-2-git-send-email-stsp@list.ru
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 548ddf7d6fd2..3e84ef16f657 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -248,18 +248,17 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, if (config_enabled(CONFIG_X86_64)) sp -= 128; - if (!onsigstack) { - /* This is the X/Open sanctioned signal stack switching. */ - if (ka->sa.sa_flags & SA_ONSTACK) { - if (current->sas_ss_size) - sp = current->sas_ss_sp + current->sas_ss_size; - } else if (config_enabled(CONFIG_X86_32) && - (regs->ss & 0xffff) != __USER_DS && - !(ka->sa.sa_flags & SA_RESTORER) && - ka->sa.sa_restorer) { - /* This is the legacy signal stack switching. */ - sp = (unsigned long) ka->sa.sa_restorer; - } + /* This is the X/Open sanctioned signal stack switching. */ + if (ka->sa.sa_flags & SA_ONSTACK) { + if (sas_ss_flags(sp) == 0) + sp = current->sas_ss_sp + current->sas_ss_size; + } else if (config_enabled(CONFIG_X86_32) && + !onsigstack && + (regs->ss & 0xffff) != __USER_DS && + !(ka->sa.sa_flags & SA_RESTORER) && + ka->sa.sa_restorer) { + /* This is the legacy signal stack switching. */ + sp = (unsigned long) ka->sa.sa_restorer; } if (fpu->fpstate_active) { |