diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2019-04-03 09:39:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 06:48:29 -0700 |
| commit | c8fb42b7b5019ecac1f9dc7fa6a3aa557facaeb7 (patch) | |
| tree | a80c002100ecf2127ed37f23b6a3b3faac90f392 /arch | |
| parent | e07fb7e7dd437330fd62420979e18b4ea3d0eb20 (diff) | |
x86/uaccess, signal: Fix AC=1 bloat
[ Upstream commit 88e4718275c1bddca6f61f300688b4553dc8584b ]
Occasionally GCC is less agressive with inlining and the following is
observed:
arch/x86/kernel/signal.o: warning: objtool: restore_sigcontext()+0x3cc: call to force_valid_ss.isra.5() with UACCESS enabled
arch/x86/kernel/signal.o: warning: objtool: do_signal()+0x384: call to frame_uc_flags.isra.0() with UACCESS enabled
Cure this by moving this code out of the AC=1 region, since it really
isn't needed for the user access.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/signal.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index b1a5d252d482..ca010dfb9682 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -129,16 +129,6 @@ static int restore_sigcontext(struct pt_regs *regs, COPY_SEG_CPL3(cs); COPY_SEG_CPL3(ss); -#ifdef CONFIG_X86_64 - /* - * Fix up SS if needed for the benefit of old DOSEMU and - * CRIU. - */ - if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && - user_64bit_mode(regs))) - force_valid_ss(regs); -#endif - get_user_ex(tmpflags, &sc->flags); regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); regs->orig_ax = -1; /* disable syscall checks */ @@ -147,6 +137,15 @@ static int restore_sigcontext(struct pt_regs *regs, buf = (void __user *)buf_val; } get_user_catch(err); +#ifdef CONFIG_X86_64 + /* + * Fix up SS if needed for the benefit of old DOSEMU and + * CRIU. + */ + if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs))) + force_valid_ss(regs); +#endif + err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32)); force_iret(); @@ -458,6 +457,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, { struct rt_sigframe __user *frame; void __user *fp = NULL; + unsigned long uc_flags; int err = 0; frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); @@ -470,9 +470,11 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, return -EFAULT; } + uc_flags = frame_uc_flags(regs); + put_user_try { /* Create the ucontext. */ - put_user_ex(frame_uc_flags(regs), &frame->uc.uc_flags); + put_user_ex(uc_flags, &frame->uc.uc_flags); put_user_ex(0, &frame->uc.uc_link); save_altstack_ex(&frame->uc.uc_stack, regs->sp); @@ -538,6 +540,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, { #ifdef CONFIG_X86_X32_ABI struct rt_sigframe_x32 __user *frame; + unsigned long uc_flags; void __user *restorer; int err = 0; void __user *fpstate = NULL; @@ -552,9 +555,11 @@ static int x32_setup_rt_frame(struct ksignal *ksig, return -EFAULT; } + uc_flags = frame_uc_flags(regs); + put_user_try { /* Create the ucontext. */ - put_user_ex(frame_uc_flags(regs), &frame->uc.uc_flags); + put_user_ex(uc_flags, &frame->uc.uc_flags); put_user_ex(0, &frame->uc.uc_link); compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); put_user_ex(0, &frame->uc.uc__pad0); |