Commit 0f2cb928 authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
Browse files

arm64: consistently pass ESR_ELx to die() 



Currently, bug_handler() and kasan_handler() call die() with '0' as the
'err' value, whereas die_kernel_fault() passes the ESR_ELx value.

For consistency, this patch ensures we always pass the ESR_ELx value to
die(). As this is only called for exceptions taken from kernel mode,
there should be no user-visible change as a result of this patch.

For UNDEFINED exceptions, I've had to modify do_undefinstr() and its
callers to pass the ESR_ELx value. In all cases the ESR_ELx value had
already been read and was available.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-4-mark.rutland@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 18906ff9

arch/arm64/include/asm/exception.h

+1 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ asmlinkage void call_on_irq_stack(struct pt_regs *regs, 
asmlinkage void asm_exit_to_user_mode(struct pt_regs *regs);



void do_mem_abort(unsigned long far, unsigned long esr, struct pt_regs *regs);

void do_undefinstr(struct pt_regs *regs);

void do_undefinstr(struct pt_regs *regs, unsigned long esr);

void do_bti(struct pt_regs *regs);

void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr,

			struct pt_regs *regs);

arch/arm64/kernel/entry-common.c

+7 −7
Original line number Diff line number Diff line
@@ -379,11 +379,11 @@ static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr) 
	exit_to_kernel_mode(regs);

}



static void noinstr el1_undef(struct pt_regs *regs)

static void noinstr el1_undef(struct pt_regs *regs, unsigned long esr)

{

	enter_from_kernel_mode(regs);

	local_daif_inherit(regs);

	do_undefinstr(regs);

	do_undefinstr(regs, esr);

	local_daif_mask();

	exit_to_kernel_mode(regs);

}
@@ -425,7 +425,7 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) 
		break;

	case ESR_ELx_EC_SYS64:

	case ESR_ELx_EC_UNKNOWN:

		el1_undef(regs);

		el1_undef(regs, esr);

		break;

	case ESR_ELx_EC_BREAKPT_CUR:

	case ESR_ELx_EC_SOFTSTP_CUR:
@@ -582,11 +582,11 @@ static void noinstr el0_sp(struct pt_regs *regs, unsigned long esr) 
	exit_to_user_mode(regs);

}



static void noinstr el0_undef(struct pt_regs *regs)

static void noinstr el0_undef(struct pt_regs *regs, unsigned long esr)

{

	enter_from_user_mode(regs);

	local_daif_restore(DAIF_PROCCTX);

	do_undefinstr(regs);

	do_undefinstr(regs, esr);

	exit_to_user_mode(regs);

}
@@ -670,7 +670,7 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) 
		el0_pc(regs, esr);

		break;

	case ESR_ELx_EC_UNKNOWN:

		el0_undef(regs);

		el0_undef(regs, esr);

		break;

	case ESR_ELx_EC_BTI:

		el0_bti(regs);
@@ -788,7 +788,7 @@ asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs) 
	case ESR_ELx_EC_CP14_MR:

	case ESR_ELx_EC_CP14_LS:

	case ESR_ELx_EC_CP14_64:

		el0_undef(regs);

		el0_undef(regs, esr);

		break;

	case ESR_ELx_EC_CP15_32:

	case ESR_ELx_EC_CP15_64:

arch/arm64/kernel/traps.c

+7 −7
Original line number Diff line number Diff line
@@ -485,7 +485,7 @@ void arm64_notify_segfault(unsigned long addr) 
	force_signal_inject(SIGSEGV, code, addr, 0);

}



void do_undefinstr(struct pt_regs *regs)

void do_undefinstr(struct pt_regs *regs, unsigned long esr)

{

	/* check for AArch32 breakpoint instructions */

	if (!aarch32_break_handler(regs))
@@ -495,7 +495,7 @@ void do_undefinstr(struct pt_regs *regs) 
		return;



	if (!user_mode(regs))

		die("Oops - Undefined instruction", regs, 0);

		die("Oops - Undefined instruction", regs, esr);



	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);

}
@@ -760,7 +760,7 @@ void do_cp15instr(unsigned long esr, struct pt_regs *regs) 
		hook_base = cp15_64_hooks;

		break;

	default:

		do_undefinstr(regs);

		do_undefinstr(regs, esr);

		return;

	}
@@ -775,7 +775,7 @@ void do_cp15instr(unsigned long esr, struct pt_regs *regs) 
	 * EL0. Fall back to our usual undefined instruction handler

	 * so that we handle these consistently.

	 */

	do_undefinstr(regs);

	do_undefinstr(regs, esr);

}

NOKPROBE_SYMBOL(do_cp15instr);

#endif
@@ -795,7 +795,7 @@ void do_sysinstr(unsigned long esr, struct pt_regs *regs) 
	 * back to our usual undefined instruction handler so that we handle

	 * these consistently.

	 */

	do_undefinstr(regs);

	do_undefinstr(regs, esr);

}

NOKPROBE_SYMBOL(do_sysinstr);
@@ -972,7 +972,7 @@ static int bug_handler(struct pt_regs *regs, unsigned long esr) 
{

	switch (report_bug(regs->pc, regs)) {

	case BUG_TRAP_TYPE_BUG:

		die("Oops - BUG", regs, 0);

		die("Oops - BUG", regs, esr);

		break;



	case BUG_TRAP_TYPE_WARN:
@@ -1040,7 +1040,7 @@ static int kasan_handler(struct pt_regs *regs, unsigned long esr) 
	 * This is something that might be fixed at some point in the future.

	 */

	if (!recover)

		die("Oops - KASAN", regs, 0);

		die("Oops - KASAN", regs, esr);



	/* If thread survives, skip over the brk instruction and continue: */

	arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);