From 637ec831ea4f09c7529ac4078399ce4e25b46341 Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Mon, 16 Sep 2019 11:51:17 +0100 Subject: arm64: mte: Handle synchronous and asynchronous tag check faults The Memory Tagging Extension has two modes of notifying a tag check fault at EL0, configurable through the SCTLR_EL1.TCF0 field: 1. Synchronous raising of a Data Abort exception with DFSC 17. 2. Asynchronous setting of a cumulative bit in TFSRE0_EL1. Add the exception handler for the synchronous exception and handling of the asynchronous TFSRE0_EL1.TF0 bit setting via a new TIF flag in do_notify_resume(). On a tag check failure in user-space, whether synchronous or asynchronous, a SIGSEGV will be raised on the faulting thread. Signed-off-by: Vincenzo Frascino Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Cc: Will Deacon --- arch/arm64/mm/fault.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch/arm64/mm/fault.c') diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index f07333e86c2f..a3bd189602df 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -641,6 +641,13 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) return 0; } +static int do_tag_check_fault(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + do_bad_area(addr, esr, regs); + return 0; +} + static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, @@ -659,7 +666,7 @@ static const struct fault_info fault_info[] = { { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 17" }, + { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 18" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 19" }, { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" }, -- cgit v1.2.3