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| author | Will Deacon <will.deacon@arm.com> | 2019-03-01 13:28:00 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-03-01 16:23:17 +0000 |
| commit | b9a4b9d084d978f80eb9210727c81804588b42ff (patch) | |
| tree | fcaf5289b28a6782441211facb51f65d02f1f196 /arch/arm64 | |
| parent | 3cd0ddb3deec43bd1cfcdd39d3dde37a0135d0c6 (diff) | |
| download | linux-0-day-b9a4b9d084d978f80eb9210727c81804588b42ff.tar.gz linux-0-day-b9a4b9d084d978f80eb9210727c81804588b42ff.tar.xz | |
arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals
FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by
taking a hardware watchpoint. Unfortunately, if a debug handler returns
a non-zero value, then we will propagate the UNKNOWN FAR value to
userspace via the si_addr field of the SIGTRAP siginfo_t.
Instead, let's set si_addr to take on the PC of the faulting instruction,
which we have available in the current pt_regs.
Cc: <stable@vger.kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/mm/fault.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index efb7b2cbead52..ef46925096f0f 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -824,11 +824,12 @@ void __init hook_debug_fault_code(int nr, debug_fault_info[nr].name = name; } -asmlinkage int __exception do_debug_exception(unsigned long addr, +asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr, struct pt_regs *regs) { const struct fault_info *inf = esr_to_debug_fault_info(esr); + unsigned long pc = instruction_pointer(regs); int rv; /* @@ -838,14 +839,14 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (user_mode(regs) && !is_ttbr0_addr(instruction_pointer(regs))) + if (user_mode(regs) && !is_ttbr0_addr(pc)) arm64_apply_bp_hardening(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { arm64_notify_die(inf->name, regs, - inf->sig, inf->code, (void __user *)addr, esr); + inf->sig, inf->code, (void __user *)pc, esr); rv = 0; } |