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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-10-12 15:15:16 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-14 09:04:09 +0200 |
| commit | 4c2de74cc8696154b283f241d74ec0bb24438e22 (patch) | |
| tree | 85fe4333599db98756971f364ef4beb654abc162 /arch/powerpc/kernel/entry_64.S | |
| parent | powerpc/ptrace: Don't use sizeof(struct pt_regs) in ptrace code (diff) | |
| download | linux-4c2de74cc8696154b283f241d74ec0bb24438e22.tar.xz linux-4c2de74cc8696154b283f241d74ec0bb24438e22.zip | |
powerpc/64: Interrupts save PPR on stack rather than thread_struct
PPR is the odd register out when it comes to interrupt handling, it is
saved in current->thread.ppr while all others are saved on the stack.
The difficulty with this is that accessing thread.ppr can cause a SLB
fault, but the SLB fault handler implementation in C change had
assumed the normal exception entry handlers would not cause an SLB
fault.
Fix this by allocating room in the interrupt stack to save PPR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 7db00ee6be48..7b1693adff2a 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -386,10 +386,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) 4: /* Anything else left to do? */ BEGIN_FTR_SECTION - lis r3,INIT_PPR@highest /* Set thread.ppr = 3 */ - ld r10,PACACURRENT(r13) + lis r3,DEFAULT_PPR@highest /* Set default PPR */ sldi r3,r3,32 /* bits 11-13 are used for ppr */ - std r3,TASKTHREADPPR(r10) + std r3,_PPR(r1) END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP) @@ -942,12 +941,6 @@ fast_exception_return: andi. r0,r3,MSR_RI beq- .Lunrecov_restore - /* Load PPR from thread struct before we clear MSR:RI */ -BEGIN_FTR_SECTION - ld r2,PACACURRENT(r13) - ld r2,TASKTHREADPPR(r2) -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - /* * Clear RI before restoring r13. If we are returning to * userspace and we take an exception after restoring r13, @@ -968,7 +961,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) andi. r0,r3,MSR_PR beq 1f BEGIN_FTR_SECTION - mtspr SPRN_PPR,r2 /* Restore PPR */ + /* Restore PPR */ + ld r2,_PPR(r1) + mtspr SPRN_PPR,r2 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ACCOUNT_CPU_USER_EXIT(r13, r2, r4) REST_GPR(13, r1) |