From 3fb69640fed1dd4d8f5b81b2ee7ccaf82e369bf5 Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Wed, 2 Nov 2016 14:40:43 +0530 Subject: [PATCH] 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: Pratyush Anand Signed-off-by: Catalin Marinas --- arch/arm64/kernel/debug-monitors.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 73ae90e..a8f8de0 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -226,6 +226,8 @@ static void send_user_sigtrap(int si_code) static int single_step_handler(unsigned long addr, unsigned int esr, struct pt_regs *regs) { + bool handler_found = false; + /* * If we are stepping a pending breakpoint, call the hw_breakpoint * handler first. @@ -233,7 +235,14 @@ static int single_step_handler(unsigned long addr, unsigned int esr, if (!reinstall_suspended_bps(regs)) 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); /* @@ -243,15 +252,8 @@ static int single_step_handler(unsigned long addr, unsigned int esr, * to the active-not-pending state). */ user_rewind_single_step(current); - } else { -#ifdef CONFIG_KPROBES - 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"); + } else if (!handler_found) { + pr_warn("Unexpected kernel single-step exception at EL1\n"); /* * Re-enable stepping since we know that we will be * returning to regs. -- 2.7.4