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| author | Will Deacon | 2019-03-01 14:28:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-04-05 22:32:55 +0200 |
| commit | bd62f1fe736e0638a2010be5d5ed51ac04c105c4 (patch) | |
| tree | 43ea7e5689b860f6aa8f9567b17d20cf31207cb4 | |
| parent | Linux 4.19.33 (diff) | |
| download | kernel-qcow2-linux-bd62f1fe736e0638a2010be5d5ed51ac04c105c4.tar.gz kernel-qcow2-linux-bd62f1fe736e0638a2010be5d5ed51ac04c105c4.tar.xz kernel-qcow2-linux-bd62f1fe736e0638a2010be5d5ed51ac04c105c4.zip | |
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>
| -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 50b30ff30de4..a4c134677285 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -827,11 +827,12 @@ 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); int rv; /* @@ -841,10 +842,10 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE) + if (user_mode(regs) && pc > TASK_SIZE) arm64_apply_bp_hardening(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { struct siginfo info; @@ -853,7 +854,7 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, 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(inf->name, regs, &info, esr); rv = 0; } |