| Message ID | 20151209201147.032e28c3@kryten (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, 2015-09-12 at 09:11:47 UTC, Anton Blanchard wrote: > Two DSCR tests have a hack in them: > > /* > * XXX: Force a context switch out so that DSCR > * current value is copied into the thread struct > * which is required for the child to inherit the > * changed value. > */ > sleep(1); > > We should not be working around this in the testcase, it is a kernel bug. > Fix it by copying the current DSCR to the child, instead of what we > had in the thread struct at last context switch. > > Signed-off-by: Anton Blanchard <anton@samba.org> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/db1231dcdb4dc6cdcbdef0ba cheers
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index ec10250..fffc2d2 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1282,7 +1282,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_DSCR)) { p->thread.dscr_inherit = current->thread.dscr_inherit; - p->thread.dscr = current->thread.dscr; + p->thread.dscr = mfspr(SPRN_DSCR); } if (cpu_has_feature(CPU_FTR_HAS_PPR)) p->thread.ppr = INIT_PPR; diff --git a/tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c b/tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c index 8265504..08a8b95 100644 --- a/tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c +++ b/tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c @@ -60,14 +60,6 @@ int dscr_inherit_exec(void) else set_dscr(dscr); - /* - * XXX: Force a context switch out so that DSCR - * current value is copied into the thread struct - * which is required for the child to inherit the - * changed value. - */ - sleep(1); - pid = fork(); if (pid == -1) { perror("fork() failed"); diff --git a/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c index 4e414ca..3e5a6d1 100644 --- a/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c +++ b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c @@ -40,14 +40,6 @@ int dscr_inherit(void) else set_dscr(dscr); - /* - * XXX: Force a context switch out so that DSCR - * current value is copied into the thread struct - * which is required for the child to inherit the - * changed value. - */ - sleep(1); - pid = fork(); if (pid == -1) { perror("fork() failed");
Two DSCR tests have a hack in them: /* * XXX: Force a context switch out so that DSCR * current value is copied into the thread struct * which is required for the child to inherit the * changed value. */ sleep(1); We should not be working around this in the testcase, it is a kernel bug. Fix it by copying the current DSCR to the child, instead of what we had in the thread struct at last context switch. Signed-off-by: Anton Blanchard <anton@samba.org> --- arch/powerpc/kernel/process.c | 2 +- tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c | 8 -------- tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c | 8 -------- 3 files changed, 1 insertion(+), 17 deletions(-)