@@ -268,13 +268,19 @@ out:
return fault;
}
-static inline bool is_permission_fault(unsigned int esr)
+static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs)
{
unsigned int ec = ESR_ELx_EC(esr);
unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
- return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM) ||
- (ec == ESR_ELx_EC_IABT_CUR && fsc_type == ESR_ELx_FSC_PERM);
+ if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR)
+ return false;
+
+ if (system_supports_ttbr0_pan())
+ return fsc_type == ESR_ELx_FSC_FAULT &&
+ (regs->pstate & PSR_PAN_BIT);
+ else
+ return fsc_type == ESR_ELx_FSC_PERM;
}
static bool is_el0_instruction_abort(unsigned int esr)
@@ -314,7 +320,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
mm_flags |= FAULT_FLAG_WRITE;
}
- if (is_permission_fault(esr) && (addr < USER_DS)) {
+ if (addr < USER_DS && is_permission_fault(esr, regs)) {
/* regs->orig_addr_limit may be 0 if we entered from EL0 */
if (regs->orig_addr_limit == KERNEL_DS)
die("Accessing user space memory with fs=KERNEL_DS", regs, esr);
@@ -506,10 +512,10 @@ static const struct fault_info {
{ do_bad, SIGBUS, 0, "unknown 17" },
{ do_bad, SIGBUS, 0, "unknown 18" },
{ do_bad, SIGBUS, 0, "unknown 19" },
- { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
- { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
- { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
- { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" },
{ do_bad, SIGBUS, 0, "synchronous parity error" },
{ do_bad, SIGBUS, 0, "unknown 25" },
{ do_bad, SIGBUS, 0, "unknown 26" },
When TTBR0_EL1 is set to the reserved page, an erroneous kernel access to user space would generate a translation fault. This patch adds the checks for the software-set PSR_PAN_BIT to emulate a permission fault and report it accordingly. This patch also updates the description of the synchronous external aborts on translation table walks. Cc: Will Deacon <will.deacon@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- arch/arm64/mm/fault.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)