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| author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
|---|---|---|
| committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
| commit | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch) | |
| tree | 7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /arch/powerpc/kernel/vector.S | |
| parent | e914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff) | |
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'arch/powerpc/kernel/vector.S')
| -rw-r--r-- | arch/powerpc/kernel/vector.S | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S index 1c2e7a343..616a6d854 100644 --- a/arch/powerpc/kernel/vector.S +++ b/arch/powerpc/kernel/vector.S @@ -70,10 +70,11 @@ _GLOBAL(load_up_altivec) MTMSRD(r5) /* enable use of AltiVec now */ isync - /* Hack: if we get an altivec unavailable trap with VRSAVE - * set to all zeros, we assume this is a broken application - * that fails to set it properly, and thus we switch it to - * all 1's + /* + * While userspace in general ignores VRSAVE, glibc uses it as a boolean + * to optimise userspace context save/restore. Whenever we take an + * altivec unavailable exception we must set VRSAVE to something non + * zero. Set it to all 1s. See also the programming note in the ISA. */ mfspr r4,SPRN_VRSAVE cmpwi 0,r4,0 |