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Commit 3fb69640 authored by Pratyush Anand's avatar Pratyush Anand Committed by Catalin Marinas
Browse files

arm64: Handle TRAP_TRACE for user mode as well 



uprobe registers a handler at step_hook. So, single_step_handler now
checks for user mode as well if there is a valid hook.

Signed-off-by: default avatarPratyush Anand <panand@redhat.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b66c9870

arch/arm64/kernel/debug-monitors.c

+12 −10
Original line number Original line Diff line number Diff line
@@ -226,6 +226,8 @@ static void send_user_sigtrap(int si_code) 
static int single_step_handler(unsigned long addr, unsigned int esr,

static int single_step_handler(unsigned long addr, unsigned int esr,

			       struct pt_regs *regs)

			       struct pt_regs *regs)

{

{

	bool handler_found = false;



	/*

	/*

	 * If we are stepping a pending breakpoint, call the hw_breakpoint

	 * If we are stepping a pending breakpoint, call the hw_breakpoint

	 * handler first.

	 * handler first.
@@ -233,7 +235,14 @@ static int single_step_handler(unsigned long addr, unsigned int esr, 
	if (!reinstall_suspended_bps(regs))

	if (!reinstall_suspended_bps(regs))

		return 0;

		return 0;





	if (user_mode(regs)) {

#ifdef	CONFIG_KPROBES

	if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)

		handler_found = true;

#endif

	if (!handler_found && call_step_hook(regs, esr) == DBG_HOOK_HANDLED)

		handler_found = true;



	if (!handler_found && user_mode(regs)) {

		send_user_sigtrap(TRAP_TRACE);

		send_user_sigtrap(TRAP_TRACE);





		/*

		/*
@@ -243,15 +252,8 @@ static int single_step_handler(unsigned long addr, unsigned int esr, 
		 * to the active-not-pending state).

		 * to the active-not-pending state).

		 */

		 */

		user_rewind_single_step(current);

		user_rewind_single_step(current);

	} else {

	} else if (!handler_found) {

#ifdef	CONFIG_KPROBES

		pr_warn("Unexpected kernel single-step exception at EL1\n");

		if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)

			return 0;

#endif

		if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)

			return 0;



		pr_warning("Unexpected kernel single-step exception at EL1\n");

		/*

		/*

		 * Re-enable stepping since we know that we will be

		 * Re-enable stepping since we know that we will be

		 * returning to regs.

		 * returning to regs.