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| author | Anton Blanchard <anton@samba.org> | 2012-09-03 16:49:47 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-09-05 16:05:21 +1000 |
| commit | 1021cb268b3025573c4811f1dee4a11260c4507b (patch) | |
| tree | 54fee24502e5c8ce2f0a96ef1b5fd62bef2dfc73 /arch/powerpc/kernel | |
| parent | 00ca0de02f80924dfff6b4f630e1dff3db005e35 (diff) | |
| download | linux-stable-1021cb268b3025573c4811f1dee4a11260c4507b.tar.gz linux-stable-1021cb268b3025573c4811f1dee4a11260c4507b.tar.bz2 linux-stable-1021cb268b3025573c4811f1dee4a11260c4507b.zip | |
powerpc: Fix DSCR inheritance in copy_thread()
If the default DSCR is non zero we set thread.dscr_inherit in
copy_thread() meaning the new thread and all its children will ignore
future updates to the default DSCR. This is not intended and is
a change in behaviour that a number of our users have hit.
We just need to inherit thread.dscr and thread.dscr_inherit from
the parent which ends up being much simpler.
This was found with the following test case:
http://ozlabs.org/~anton/junkcode/dscr_default_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> # 3.0+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 710f400476de..1a1f2ddfb581 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -802,16 +802,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, #endif /* CONFIG_PPC_STD_MMU_64 */ #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_DSCR)) { - if (current->thread.dscr_inherit) { - p->thread.dscr_inherit = 1; - p->thread.dscr = current->thread.dscr; - } else if (0 != dscr_default) { - p->thread.dscr_inherit = 1; - p->thread.dscr = dscr_default; - } else { - p->thread.dscr_inherit = 0; - p->thread.dscr = 0; - } + p->thread.dscr_inherit = current->thread.dscr_inherit; + p->thread.dscr = current->thread.dscr; } #endif |