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| author | Thomas Gleixner <tglx@linutronix.de> | 2022-07-12 14:01:06 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-07-12 14:23:32 +0200 |
| commit | c27c753ea6fd1237f4f96abf8b623d7bab505513 (patch) | |
| tree | a4d18070f91417e41f85c3f4fb1906f4acce0893 /arch | |
| parent | f43b9876e857c739d407bc56df288b0ebe1a9164 (diff) | |
| download | linux-stable-c27c753ea6fd1237f4f96abf8b623d7bab505513.tar.gz linux-stable-c27c753ea6fd1237f4f96abf8b623d7bab505513.tar.bz2 linux-stable-c27c753ea6fd1237f4f96abf8b623d7bab505513.zip | |
x86/static_call: Serialize __static_call_fixup() properly
__static_call_fixup() invokes __static_call_transform() without holding
text_mutex, which causes lockdep to complain in text_poke_bp().
Adding the proper locking cures that, but as this is either used during
early boot or during module finalizing, it's not required to use
text_poke_bp(). Add an argument to __static_call_transform() which tells
it to use text_poke_early() for it.
Fixes: ee88d363d156 ("x86,static_call: Use alternative RET encoding")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/static_call.c | 13 |
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; } |