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authorLinus Torvalds <torvalds@linux-foundation.org>2022-07-12 08:40:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-07-12 08:40:09 -0700
commit0d8ba24e72b6ec45b1d62148c711bad54483b29a (patch)
tree9bc4edacaba87839513c3053120995e8e959d793 /arch
parentce114c866860aa9eae3f50974efc68241186ba60 (diff)
parentc27c753ea6fd1237f4f96abf8b623d7bab505513 (diff)
Merge tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull lockdep fix for x86 retbleed from Borislav Petkov: - Fix lockdep complaint for __static_call_fixup() * tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/static_call: Serialize __static_call_fixup() properly
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/static_call.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index be7038a0da4d..aaaba85d6d7f 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -25,7 +25,8 @@ static const u8 xor5rax[] = { 0x2e, 0x2e, 0x2e, 0x31, 0xc0 };
static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc };
-static void __ref __static_call_transform(void *insn, enum insn_type type, void *func)
+static void __ref __static_call_transform(void *insn, enum insn_type type,
+ void *func, bool modinit)
{
const void *emulate = NULL;
int size = CALL_INSN_SIZE;
@@ -60,7 +61,7 @@ static void __ref __static_call_transform(void *insn, enum insn_type type, void
if (memcmp(insn, code, size) == 0)
return;
- if (unlikely(system_state == SYSTEM_BOOTING))
+ if (system_state == SYSTEM_BOOTING || modinit)
return text_poke_early(insn, code, size);
text_poke_bp(insn, code, size, emulate);
@@ -114,12 +115,12 @@ void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
if (tramp) {
__static_call_validate(tramp, true, true);
- __static_call_transform(tramp, __sc_insn(!func, true), func);
+ __static_call_transform(tramp, __sc_insn(!func, true), func, false);
}
if (IS_ENABLED(CONFIG_HAVE_STATIC_CALL_INLINE) && site) {
__static_call_validate(site, tail, false);
- __static_call_transform(site, __sc_insn(!func, tail), func);
+ __static_call_transform(site, __sc_insn(!func, tail), func, false);
}
mutex_unlock(&text_mutex);
@@ -145,8 +146,10 @@ bool __static_call_fixup(void *tramp, u8 op, void *dest)
return false;
}
+ mutex_lock(&text_mutex);
if (op == RET_INSN_OPCODE || dest == &__x86_return_thunk)
- __static_call_transform(tramp, RET, NULL);
+ __static_call_transform(tramp, RET, NULL, true);
+ mutex_unlock(&text_mutex);
return true;
}