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| author | Anton Blanchard <anton@samba.org> | 2015-12-09 20:11:47 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-12-10 21:11:13 +1100 |
| commit | db1231dcdb4dc6cdcbdef0babe641a9162c0dc98 (patch) | |
| tree | 34250a59e15b1d3e9620a7a9e3083b0a4fa82bce | |
| parent | 20dbe67062062c2a790832f0d30e73dba45df7c4 (diff) | |
| download | linux-db1231dcdb4dc6cdcbdef0babe641a9162c0dc98.tar.gz linux-db1231dcdb4dc6cdcbdef0babe641a9162c0dc98.tar.bz2 linux-db1231dcdb4dc6cdcbdef0babe641a9162c0dc98.zip | |
powerpc: Fix DSCR inheritance over fork()
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/kernel/process.c | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c | 8 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c | 8 |
3 files changed, 1 insertions, 17 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 9da7b5f0c3a5..6f76f25c3ee8 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1287,7 +1287,7 @@ 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 8265504de571..08a8b95e3bc1 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 4e414caf7f40..3e5a6d195e9a 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"); |