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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-13 17:01:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-13 17:01:03 -0700 |
| commit | 4d5ac4b8ca1ecbdb600097a26071abc5b47500bf (patch) | |
| tree | 4ccef33588c8a944140b291646fd741ef493cb62 /arch | |
| parent | Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff) | |
| parent | x86/paravirt: Fix spectre-v2 mitigations for paravirt guests (diff) | |
| download | linux-dev-4d5ac4b8ca1ecbdb600097a26071abc5b47500bf.tar.xz linux-dev-4d5ac4b8ca1ecbdb600097a26071abc5b47500bf.zip | |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 fixes from Thomas Gleixner:
"Two fixes for x86:
- Provide a declaration for native_save_fl() which unbreaks the
wreckage caused by making it 'extern inline'.
- Fix the failing paravirt patching which is supposed to replace
indirect with direct calls. The wreckage is caused by an incorrect
clobber test"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/paravirt: Fix spectre-v2 mitigations for paravirt guests
x86/irqflags: Provide a declaration for native_save_fl
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 14 |
2 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index c4fc17220df9..c14f2a74b2be 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -13,6 +13,8 @@ * Interrupt control: */ +/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */ +extern inline unsigned long native_save_fl(void); extern inline unsigned long native_save_fl(void) { unsigned long flags; diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 99dc79e76bdc..930c88341e4e 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -88,10 +88,12 @@ unsigned paravirt_patch_call(void *insnbuf, struct branch *b = insnbuf; unsigned long delta = (unsigned long)target - (addr+5); - if (tgt_clobbers & ~site_clobbers) - return len; /* target would clobber too much for this site */ - if (len < 5) + if (len < 5) { +#ifdef CONFIG_RETPOLINE + WARN_ONCE("Failing to patch indirect CALL in %ps\n", (void *)addr); +#endif return len; /* call too long for patch site */ + } b->opcode = 0xe8; /* call */ b->delta = delta; @@ -106,8 +108,12 @@ unsigned paravirt_patch_jmp(void *insnbuf, const void *target, struct branch *b = insnbuf; unsigned long delta = (unsigned long)target - (addr+5); - if (len < 5) + if (len < 5) { +#ifdef CONFIG_RETPOLINE + WARN_ONCE("Failing to patch indirect JMP in %ps\n", (void *)addr); +#endif return len; /* call too long for patch site */ + } b->opcode = 0xe9; /* jmp */ b->delta = delta; |