diff options
author | Nicholas Piggin <npiggin@gmail.com> | 2018-10-13 00:15:16 +1100 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-14 18:04:09 +1100 |
commit | 4c2de74cc8696154b283f241d74ec0bb24438e22 (patch) | |
tree | 85fe4333599db98756971f364ef4beb654abc162 /arch/powerpc/kernel | |
parent | 3eeacd9f4ea33546f272fcf131d6a11edbe3b4a6 (diff) | |
download | linux-4c2de74cc8696154b283f241d74ec0bb24438e22.tar.bz2 |
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')
-rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/entry_64.S | 15 | ||||
-rw-r--r-- | arch/powerpc/kernel/process.c | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/ptrace.c | 4 |
4 files changed, 9 insertions, 14 deletions
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 2eb4923f8468..92156c61d21c 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -89,7 +89,6 @@ int main(void) #ifdef CONFIG_PPC64 DEFINE(SIGSEGV, SIGSEGV); DEFINE(NMI_MASK, NMI_MASK); - OFFSET(TASKTHREADPPR, task_struct, thread.ppr); #else OFFSET(THREAD_INFO, task_struct, stack); DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16)); @@ -323,6 +322,7 @@ int main(void) STACK_PT_REGS_OFFSET(_ESR, dsisr); #else /* CONFIG_PPC64 */ STACK_PT_REGS_OFFSET(SOFTE, softe); + STACK_PT_REGS_OFFSET(_PPR, ppr); #endif /* CONFIG_PPC64 */ #if defined(CONFIG_PPC32) 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) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 0ed8d0968515..f9d1cca28cce 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1710,7 +1710,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, p->thread.dscr = mfspr(SPRN_DSCR); } if (cpu_has_feature(CPU_FTR_HAS_PPR)) - p->thread.ppr = INIT_PPR; + childregs->ppr = DEFAULT_PPR; p->thread.tidr = 0; #endif diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index c7d0d0c1e34d..afb819f4ca68 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -1609,7 +1609,7 @@ static int ppr_get(struct task_struct *target, void *kbuf, void __user *ubuf) { return user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.ppr, 0, sizeof(u64)); + &target->thread.regs->ppr, 0, sizeof(u64)); } static int ppr_set(struct task_struct *target, @@ -1618,7 +1618,7 @@ static int ppr_set(struct task_struct *target, const void *kbuf, const void __user *ubuf) { return user_regset_copyin(&pos, &count, &kbuf, &ubuf, - &target->thread.ppr, 0, sizeof(u64)); + &target->thread.regs->ppr, 0, sizeof(u64)); } static int dscr_get(struct task_struct *target, |