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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-01-31 10:09:00 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-02-23 22:31:40 +1100 |
| commit | a7916a1de526162d73e894b6d3ebd895d4302078 (patch) | |
| tree | d34624a17b6475cc0e45bafdde2c6d51b6a70626 /arch/powerpc/kernel/entry_32.S | |
| parent | ed1cd6deb013a11959d17a94e35ce159197632da (diff) | |
| download | lwn-a7916a1de526162d73e894b6d3ebd895d4302078.tar.gz lwn-a7916a1de526162d73e894b6d3ebd895d4302078.zip | |
powerpc: regain entire stack space
thread_info is not anymore in the stack, so the entire stack
can now be used.
There is also no risk anymore of corrupting task_cpu(p) with a
stack overflow so the patch removes the test.
When doing this, an explicit test for NULL stack pointer is
needed in validate_sp() as it is not anymore implicitely covered
by the sizeof(thread_info) gap.
In the meantime, with the previous patch all pointers to the stacks
are not anymore pointers to thread_info so this patch changes them
to void*
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index f3618353c1c4..424e7265e790 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -97,14 +97,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,_SRR1(r11) - /* set the stack limit to the current stack - * and set the limit to protect the thread_info - * struct - */ + /* set the stack limit to the current stack */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -121,14 +118,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,crit_srr1@l(0) - /* set the stack limit to the current stack - * and set the limit to protect the thread_info - * struct - */ + /* set the stack limit to the current stack */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif |