linux/arch/arm64/include/asm/traps.h
Peter Collingbourne dceec3ff78 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>
2020-11-23 18:17:39 +00:00

104 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/traps.h
*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_TRAP_H
#define __ASM_TRAP_H
#include <linux/list.h>
#include <asm/esr.h>
#include <asm/sections.h>
struct pt_regs;
struct undef_hook {
struct list_head node;
u32 instr_mask;
u32 instr_val;
u64 pstate_mask;
u64 pstate_val;
int (*fn)(struct pt_regs *regs, u32 instr);
};
void register_undef_hook(struct undef_hook *hook);
void unregister_undef_hook(struct undef_hook *hook);
void force_signal_inject(int signal, int code, unsigned long address, unsigned int err);
void arm64_notify_segfault(unsigned long addr);
void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str);
void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str);
void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str);
/*
* Move regs->pc to next instruction and do necessary setup before it
* is executed.
*/
void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size);
static inline int __in_irqentry_text(unsigned long ptr)
{
return ptr >= (unsigned long)&__irqentry_text_start &&
ptr < (unsigned long)&__irqentry_text_end;
}
static inline int in_entry_text(unsigned long ptr)
{
return ptr >= (unsigned long)&__entry_text_start &&
ptr < (unsigned long)&__entry_text_end;
}
/*
* CPUs with the RAS extensions have an Implementation-Defined-Syndrome bit
* to indicate whether this ESR has a RAS encoding. CPUs without this feature
* have a ISS-Valid bit in the same position.
* If this bit is set, we know its not a RAS SError.
* If its clear, we need to know if the CPU supports RAS. Uncategorized RAS
* errors share the same encoding as an all-zeros encoding from a CPU that
* doesn't support RAS.
*/
static inline bool arm64_is_ras_serror(u32 esr)
{
WARN_ON(preemptible());
if (esr & ESR_ELx_IDS)
return false;
if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
return true;
else
return false;
}
/*
* Return the AET bits from a RAS SError's ESR.
*
* It is implementation defined whether Uncategorized errors are containable.
* We treat them as Uncontainable.
* Non-RAS SError's are reported as Uncontained/Uncategorized.
*/
static inline u32 arm64_ras_serror_get_severity(u32 esr)
{
u32 aet = esr & ESR_ELx_AET;
if (!arm64_is_ras_serror(esr)) {
/* Not a RAS error, we can't interpret the ESR. */
return ESR_ELx_AET_UC;
}
/*
* AET is RES0 if 'the value returned in the DFSC field is not
* [ESR_ELx_FSC_SERROR]'
*/
if ((esr & ESR_ELx_FSC) != ESR_ELx_FSC_SERROR) {
/* No severity information : Uncategorized */
return ESR_ELx_AET_UC;
}
return aet;
}
bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr);
void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr);
#endif