@@ -589,7 +589,7 @@ el1_undef:
inherit_daif pstate=x23, tmp=x2
mov x0, sp
bl do_undefinstr
- ASM_BUG()
+ kernel_exit 1
el1_dbg:
/*
* Debug exception handling
@@ -310,10 +310,12 @@ static int call_undef_hook(struct pt_regs *regs)
int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
void __user *pc = (void __user *)instruction_pointer(regs);
- if (!user_mode(regs))
- return 1;
-
- if (compat_thumb_mode(regs)) {
+ if (!user_mode(regs)) {
+ __le32 instr_le;
+ if (probe_kernel_address((__force __le32 *)pc, instr_le))
+ goto exit;
+ instr = le32_to_cpu(instr_le);
+ } else if (compat_thumb_mode(regs)) {
/* 16-bit Thumb instruction */
__le16 instr_le;
if (get_user(instr_le, (__le16 __user *)pc))
@@ -407,6 +409,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
return;
force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+ BUG_ON(!user_mode(regs));
}
void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
Rather than panic() when taking an undefined instruction exception from EL1, allow a hook to be registered in case we want to emulate the instruction, like we will for the SSBS PSTATE manipulation instructions. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/entry.S | 2 +- arch/arm64/kernel/traps.c | 11 +++++++---- 2 files changed, 8 insertions(+), 5 deletions(-)