Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 53d07e21 authored by Pratyush Anand's avatar Pratyush Anand Committed by Catalin Marinas
Browse files

arm64: Handle TRAP_BRKPT for user mode as well 



uprobe is registered at break_hook with a unique ESR code. So, when a
TRAP_BRKPT occurs, call_break_hook checks if it was for uprobe. If not,
then send a SIGTRAP to user.

Signed-off-by: default avatarPratyush Anand <panand@redhat.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 3fb69640

arch/arm64/kernel/debug-monitors.c

+11 −7
Original line number Diff line number Diff line
@@ -306,16 +306,20 @@ NOKPROBE_SYMBOL(call_break_hook); 
static int brk_handler(unsigned long addr, unsigned int esr,

		       struct pt_regs *regs)

{

	if (user_mode(regs)) {

		send_user_sigtrap(TRAP_BRKPT);

	}

	bool handler_found = false;



#ifdef	CONFIG_KPROBES

	else if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) {

		if (kprobe_breakpoint_handler(regs, esr) != DBG_HOOK_HANDLED)

			return -EFAULT;

	if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) {

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

			handler_found = true;

	}

#endif

	else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {

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

		handler_found = true;



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

		send_user_sigtrap(TRAP_BRKPT);

	} else if (!handler_found) {

		pr_warn("Unexpected kernel BRK exception at EL1\n");

		return -EFAULT;

	}