[PATCH 02/10] signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered

From: Eric W. Biederman
Date: Tue Jan 23 2018 - 16:11:06 EST


Instead of jumpping while !is_compat_task placee all of the code
inside of an if (is_compat_task) block. This allows the int i
variable to be properly limited to the compat block no matter how the
rest of ptrace_hbptriggered changes.

In a following change a non-variable declaration will preceed
was made independent to ensure the code is easy to review.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/arm64/kernel/ptrace.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 7c44658b316d..0a1cf830e4b3 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -188,26 +188,23 @@ static void ptrace_hbptriggered(struct perf_event *bp,
};

#ifdef CONFIG_COMPAT
- int i;
-
- if (!is_compat_task())
- goto send_sig;
+ if (is_compat_task()) {
+ int i;

- for (i = 0; i < ARM_MAX_BRP; ++i) {
- if (current->thread.debug.hbp_break[i] == bp) {
- info.si_errno = (i << 1) + 1;
- break;
+ for (i = 0; i < ARM_MAX_BRP; ++i) {
+ if (current->thread.debug.hbp_break[i] == bp) {
+ info.si_errno = (i << 1) + 1;
+ break;
+ }
}
- }

- for (i = 0; i < ARM_MAX_WRP; ++i) {
- if (current->thread.debug.hbp_watch[i] == bp) {
- info.si_errno = -((i << 1) + 1);
- break;
+ for (i = 0; i < ARM_MAX_WRP; ++i) {
+ if (current->thread.debug.hbp_watch[i] == bp) {
+ info.si_errno = -((i << 1) + 1);
+ break;
+ }
}
}
-
-send_sig:
#endif
force_sig_info(SIGTRAP, &info, current);
}
--
2.14.1