* [LTP] [PATCH v3] syscalls/signal06: loop being clobbered by syscall on clang
@ 2022-08-19 23:27 Edward Liaw via ltp
2022-08-24 8:25 ` Cyril Hrubis
0 siblings, 1 reply; 2+ messages in thread
From: Edward Liaw via ltp @ 2022-08-19 23:27 UTC (permalink / raw)
To: ltp; +Cc: vmartensson, kernel-team
Indicate to the compiler that the syscall will modify registers rcx
and r11 to prevent loop from getting clobbered.
Signed-off-by: Edward Liaw <edliaw@google.com>
---
I added an output operand for the result so that the compiler would know
that rax is clobbered as well.
---
testcases/kernel/syscalls/signal/signal06.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/testcases/kernel/syscalls/signal/signal06.c b/testcases/kernel/syscalls/signal/signal06.c
index 64f886ee3..cf0706ea4 100644
--- a/testcases/kernel/syscalls/signal/signal06.c
+++ b/testcases/kernel/syscalls/signal/signal06.c
@@ -72,8 +72,8 @@ void test(void)
while (D == VALUE && loop < LOOPS) {
/* sys_tkill(pid, SIGHUP); asm to avoid save/reload
* fp regs around c call */
- asm ("" : : "a"(__NR_tkill), "D"(pid), "S"(SIGHUP));
- asm ("syscall" : : : "ax");
+ int unused;
+ asm volatile ("syscall" : "=a"(unused) : "a"(__NR_tkill), "D"(pid), "S"(SIGHUP) : "rcx", "r11");
loop++;
}
--
2.37.2.609.g9ff673ca1a-goog
--
Mailing list info: https://lists.linux.it/listinfo/ltp
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [LTP] [PATCH v3] syscalls/signal06: loop being clobbered by syscall on clang
2022-08-19 23:27 [LTP] [PATCH v3] syscalls/signal06: loop being clobbered by syscall on clang Edward Liaw via ltp
@ 2022-08-24 8:25 ` Cyril Hrubis
0 siblings, 0 replies; 2+ messages in thread
From: Cyril Hrubis @ 2022-08-24 8:25 UTC (permalink / raw)
To: Edward Liaw; +Cc: vmartensson, kernel-team, ltp
Hi!
Applied, thanks.
--
Cyril Hrubis
chrubis@suse.cz
--
Mailing list info: https://lists.linux.it/listinfo/ltp
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