On Thu, 19 Mar 2015, Jakub Jelinek wrote:
> Hi!
>
> This patch fixes the other part of the PR. On this testcase, ICF creates
> a thunk and sets gimple_call_set_tail true on the call in there. No
> TSAN_FUNC_EXIT internal call is added, which isn't a big deal, tsan pass
> has code to add it if there are none. But, nothing was clearing the tail
> call flag when this was done, and with -fsanitize=thread in sanitized
> functions all functions that call other functions must start with the
> __tsan_func_entry call and call __tsan_func_exit at the end (unless they are
> noreturn). Thus, we can only tail call __tsan_func_exit in instrumented
> functions. The patch clears the tail call flag on all calls but
> TSAN_FUNC_EXIT (for which instrument_gimple isn't called at all).
>
> Regtested on x86_64-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2015-03-19 Bernd Edlinger <bernd.edlin...@hotmail.de>
> Jakub Jelinek <ja...@redhat.com>
>
> PR sanitizer/65400
> * tsan.c (instrument_gimple): Clear tail call flag on
> calls.
>
> * c-c++-common/tsan/pr65400-3.c: New test.
>
> --- gcc/tsan.c.jj 2015-01-19 09:31:24.000000000 +0100
> +++ gcc/tsan.c 2015-03-19 09:51:39.086804965 +0100
> @@ -680,6 +680,10 @@ instrument_gimple (gimple_stmt_iterator
> && (gimple_call_fndecl (stmt)
> != builtin_decl_implicit (BUILT_IN_TSAN_INIT)))
> {
> + /* All functions with function call will have exit instrumented,
> + therefore no function calls other than __tsan_func_exit
> + shall appear in the functions. */
> + gimple_call_set_tail (as_a <gcall *> (stmt), false);
> if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
> instrument_builtin_call (gsi);
> return true;
> --- gcc/testsuite/c-c++-common/tsan/pr65400-3.c.jj 2015-03-19
> 10:07:15.453302478 +0100
> +++ gcc/testsuite/c-c++-common/tsan/pr65400-3.c 2015-03-19
> 10:27:11.941515580 +0100
> @@ -0,0 +1,75 @@
> +/* PR sanitizer/65400 */
> +/* { dg-shouldfail "tsan" } */
> +/* { dg-additional-options "-fno-omit-frame-pointer -ldl" } */
> +
> +#include <pthread.h>
> +#include "tsan_barrier.h"
> +
> +static pthread_barrier_t barrier;
> +int v;
> +
> +int
> +fn1 (int a, int b, int c)
> +{
> + int r = (a ^ b) % c;
> + r = r * a * b + c;
> + r = (r ^ b) % c;
> + return r;
> +}
> +
> +int
> +fn2 (int a, int b, int c)
> +{
> + int r = (a ^ b) % c;
> + r = r * a * b + c;
> + r = (r ^ b) % c;
> + return r;
> +}
> +
> +__attribute__((noinline, noclone)) void
> +foo (void)
> +{
> + barrier_wait (&barrier);
> + barrier_wait (&barrier);
> + v++;
> +}
> +
> +__attribute__((noinline, noclone)) void
> +bar (void)
> +{
> + int (*fna) (int, int, int);
> + int (*fnb) (int, int, int);
> + int i;
> + asm ("" : "=g" (fna) : "0" (fn1));
> + asm ("" : "=g" (fnb) : "0" (fn2));
> + for (i = 0; i < 128; i++)
> + {
> + fna (0, 0, i + 1);
> + fnb (0, 0, i + 1);
> + }
> + foo ();
> +}
> +
> +__attribute__((noinline, noclone)) void *
> +tf (void *arg)
> +{
> + (void) arg;
> + bar ();
> + return NULL;
> +}
> +
> +int
> +main ()
> +{
> + pthread_t th;
> + barrier_init (&barrier, 2);
> + if (pthread_create (&th, NULL, tf, NULL))
> + return 0;
> + barrier_wait (&barrier);
> + v++;
> + barrier_wait (&barrier);
> + pthread_join (th, NULL);
> + return 0;
> +}
> +
> +/* { dg-output "WARNING: ThreadSanitizer: data race.*#2 _?tf" } */
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Jennifer Guild,
Dilip Upmanyu, Graham Norton HRB 21284 (AG Nuernberg)
