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Merge tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm…
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…/linux/kernel/git/tip/tip

Pull objtool fix from Thomas Gleixner:
 "A single objtool fix to handle the PUSHF/POPF validation correctly for
  the paravirt changes which modified arch_local_irq_restore not to use
  popf"

* tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool,x86: Fix uaccess PUSHF/POPF validation
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torvalds committed Mar 14, 2021
2 parents fa509ff + ba08abc commit 19469d2
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Showing 2 changed files with 7 additions and 6 deletions.
10 changes: 4 additions & 6 deletions arch/x86/include/asm/smap.h
Original file line number Diff line number Diff line change
Expand Up @@ -58,9 +58,8 @@ static __always_inline unsigned long smap_save(void)
unsigned long flags;

asm volatile ("# smap_save\n\t"
ALTERNATIVE("jmp 1f", "", X86_FEATURE_SMAP)
"pushf; pop %0; " __ASM_CLAC "\n\t"
"1:"
ALTERNATIVE("", "pushf; pop %0; " __ASM_CLAC "\n\t",
X86_FEATURE_SMAP)
: "=rm" (flags) : : "memory", "cc");

return flags;
Expand All @@ -69,9 +68,8 @@ static __always_inline unsigned long smap_save(void)
static __always_inline void smap_restore(unsigned long flags)
{
asm volatile ("# smap_restore\n\t"
ALTERNATIVE("jmp 1f", "", X86_FEATURE_SMAP)
"push %0; popf\n\t"
"1:"
ALTERNATIVE("", "push %0; popf\n\t",
X86_FEATURE_SMAP)
: : "g" (flags) : "memory", "cc");
}

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3 changes: 3 additions & 0 deletions tools/objtool/check.c
Original file line number Diff line number Diff line change
Expand Up @@ -2442,6 +2442,9 @@ static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
if (update_cfi_state(insn, &state->cfi, op))
return 1;

if (!insn->alt_group)
continue;

if (op->dest.type == OP_DEST_PUSHF) {
if (!state->uaccess_stack) {
state->uaccess_stack = 1;
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