diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-03-01 13:28:00 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-27 09:33:47 +0200 |
| commit | a930f8ce20034ca7373eb2a3e91c2b9f6d5bb64c (patch) | |
| tree | 45d3ca8bcd00a2bf824239526aa3f9640aa94547 /arch/arm64/mm | |
| parent | 12ae58ca7ec42fe23df5d0b0d01bce2ccb728fd5 (diff) | |
arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals
commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/mm')
| -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 04c4b88706d8..89abdf9af4e6 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -589,11 +589,12 @@ 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 = debug_fault_info + DBG_ESR_EVT(esr); + unsigned long pc = instruction_pointer(regs); struct siginfo info; int rv; @@ -604,16 +605,16 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", - inf->name, esr, addr); + inf->name, esr, pc); info.si_signo = inf->sig; info.si_errno = 0; info.si_code = inf->code; - info.si_addr = (void __user *)addr; + info.si_addr = (void __user *)pc; arm64_notify_die("", regs, &info, 0); rv = 0; } |