[PATCH 01/12] arm64/bti: Add BTI landing pad to __sdei_asm_handler()
Josh Poimboeuf <[email protected]>
| Newsgroups | org.kernel.vger.linux-toolchains,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.live-patching |
|---|---|
| Message-ID | <99226432cc316215829655c787f71a70f06d1600.1786768375.git.jpoimboe@kernel.org> |
With CONFIG_UNMAP_KERNEL_AT_EL0, __sdei_asm_entry_trampoline() indirect
jumps to __sdei_asm_handler(). Add "bti j" to prevent a Branch Target
exception.
Discovered by code inspection.
Fixes: c50d32859e70 ("arm64: Add types to indirect called assembly functions")
Signed-off-by: Josh Poimboeuf <[email protected]>
---
arch/arm64/kernel/entry.S | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index e0db14e9c843a..16c21fcb41976 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -976,6 +976,7 @@ NOKPROBE(__sdei_asm_exit_trampoline)
* want them.
*/
SYM_CODE_START(__sdei_asm_handler)
+ bti j
stp x2, x3, [x1, #SDEI_EVENT_INTREGS + S_PC]
stp x4, x5, [x1, #SDEI_EVENT_INTREGS + 16 * 2]
stp x6, x7, [x1, #SDEI_EVENT_INTREGS + 16 * 3]
--
2.55.0