diff options
| author | Anton Blanchard <anton@samba.org> | 2016-05-29 22:03:51 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-06-14 13:58:25 +1000 |
| commit | d96f234f47aff593538f9e3d674967078f56bc28 (patch) | |
| tree | 9b76934c91abcf4b3bc883e17ce698049575781d | |
| parent | 8eb9803723a14fd12675641b953e4ccbd86187a8 (diff) | |
powerpc: Avoid load hit store in setup_sigcontext()
In setup_sigcontext(), we set current->thread.vrsave then use it
straight after. Since current is hidden from the compiler via inline
assembly, it cannot optimise this and we end up with a load hit store.
Fix this by using a temporary.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 25520794aa37..7e49984d4331 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -104,6 +104,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, */ #ifdef CONFIG_ALTIVEC elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); + unsigned long vrsave; #endif unsigned long msr = regs->msr; long err = 0; @@ -125,9 +126,13 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, /* We always copy to/from vrsave, it's 0 if we don't have or don't * use altivec. */ - if (cpu_has_feature(CPU_FTR_ALTIVEC)) - current->thread.vrsave = mfspr(SPRN_VRSAVE); - err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); + vrsave = 0; + if (cpu_has_feature(CPU_FTR_ALTIVEC)) { + vrsave = mfspr(SPRN_VRSAVE); + current->thread.vrsave = vrsave; + } + + err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); #else /* CONFIG_ALTIVEC */ err |= __put_user(0, &sc->v_regs); #endif /* CONFIG_ALTIVEC */ |