[RFC 6/8] ARM64: Handle TRAP_HWBRKPT for user mode as well

From: Pratyush Anand
Date: Wed Dec 31 2014 - 10:23:02 EST


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 <panand@xxxxxxxxxx>
---
arch/arm64/kernel/debug-monitors.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index b056369fd47d..2676b8655241 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -236,6 +236,9 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
if (!reinstall_suspended_bps(regs))
return 0;

+ if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+
if (user_mode(regs)) {
info.si_signo = SIGTRAP;
info.si_errno = 0;
@@ -251,9 +254,6 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
*/
user_rewind_single_step(current);
} else {
- 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
--
2.1.0

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