diff options
| author | Peter Collingbourne <pcc@google.com> | 2020-11-20 12:33:46 -0800 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-11-23 18:17:39 +0000 |
| commit | dceec3ff78076757311d92a388d50d0251fb7dbb (patch) | |
| tree | e51d2de16335fcd21dce9f5342846d5e868b14ad /arch/arm64/include/asm/signal.h | |
| parent | 6ac05e832a9e96f9b1c42a8917cdd317d7b6c8fa (diff) | |
arm64: expose FAR_EL1 tag bits in siginfo
The kernel currently clears the tag bits (i.e. bits 56-63) in the fault
address exposed via siginfo.si_addr and sigcontext.fault_address. However,
the tag bits may be needed by tools in order to accurately diagnose
memory errors, such as HWASan [1] or future tools based on the Memory
Tagging Extension (MTE).
Expose these bits via the arch_untagged_si_addr mechanism, so that
they are only exposed to signal handlers with the SA_EXPOSE_TAGBITS
flag set.
[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://linux-review.googlesource.com/id/Ia8876bad8c798e0a32df7c2ce1256c4771c81446
Link: https://lore.kernel.org/r/0010296597784267472fa13b39f8238d87a72cf8.1605904350.git.pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/signal.h')
| -rw-r--r-- | arch/arm64/include/asm/signal.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h new file mode 100644 index 000000000000..ef449f5f4ba8 --- /dev/null +++ b/arch/arm64/include/asm/signal.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ARM64_ASM_SIGNAL_H +#define __ARM64_ASM_SIGNAL_H + +#include <asm/memory.h> +#include <uapi/asm/signal.h> +#include <uapi/asm/siginfo.h> + +static inline void __user *arch_untagged_si_addr(void __user *addr, + unsigned long sig, + unsigned long si_code) +{ + /* + * For historical reasons, all bits of the fault address are exposed as + * address bits for watchpoint exceptions. New architectures should + * handle the tag bits consistently. + */ + if (sig == SIGTRAP && si_code == TRAP_BRKPT) + return addr; + + return untagged_addr(addr); +} +#define arch_untagged_si_addr arch_untagged_si_addr + +#endif |