From 1f150a5e5a9630492742def51ebbf665051fbada Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Wed, 14 Dec 2016 12:32:16 -0800 Subject: [PATCH] Revert "FROMLIST: arm64: Handle faults caused by inadvertent user access with PAN enabled" This reverts commit 5dc2b7c7bb33138270ff9494be6cf334bd3d20e1. Bug: 31432001 Change-Id: I384a9af199f502f8fa3ae3733db67a4c547dbd55 Signed-off-by: Sami Tolvanen --- arch/arm64/mm/fault.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 9cedb10b1107..0aacbd763e6b 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -246,19 +246,13 @@ out: return fault; } -static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs) +static inline bool is_permission_fault(unsigned int esr) { unsigned int ec = ESR_ELx_EC(esr); unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; - if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR) - return false; - - if (system_uses_ttbr0_pan()) - return fsc_type == ESR_ELx_FSC_FAULT && - (regs->pstate & PSR_PAN_BIT); - else - return fsc_type == ESR_ELx_FSC_PERM; + 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); } static bool is_el0_instruction_abort(unsigned int esr) @@ -299,7 +293,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, mm_flags |= FAULT_FLAG_WRITE; } - if (addr < USER_DS && is_permission_fault(esr, regs)) { + if (is_permission_fault(esr) && (addr < USER_DS)) { /* 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); @@ -484,10 +478,10 @@ 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 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 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 parity error" }, { do_bad, SIGBUS, 0, "unknown 25" }, { do_bad, SIGBUS, 0, "unknown 26" },