Re: [PATCH] powerpc/32: Fix critical and debug interrupts on BOOKE
From: Christophe Leroy
Date: Wed Aug 04 2021 - 01:53:00 EST
Hi Radu,
Le 07/07/2021 à 07:55, Christophe Leroy a écrit :
32 bits BOOKE have special interrupts for debug and other
critical events.
Were you able to test this patch ?
Thanks
Christophe
When handling those interrupts, dedicated registers are saved
in the stack frame in addition to the standard registers, leading
to a shift of the pt_regs struct.
Since commit db297c3b07af ("powerpc/32: Don't save thread.regs on
interrupt entry"), the pt_regs struct is expected to be at the
same place all the time.
Instead of handling a special struct in addition to pt_regs, just
add those special registers to struct pt_regs.
Reported-by: Radu Rendec <radu.rendec@xxxxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Fixes: db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry")
Cc: stable@xxxxxxxxxxxxxxx
---
arch/powerpc/include/asm/ptrace.h | 16 ++++++++++++++++
arch/powerpc/kernel/asm-offsets.c | 31 ++++++++++++++-----------------
arch/powerpc/kernel/head_booke.h | 27 +++------------------------
3 files changed, 33 insertions(+), 41 deletions(-)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 3e5d470a6155..14422e851494 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -70,6 +70,22 @@ struct pt_regs
unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */
};
#endif
+#if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
+ struct { /* Must be a multiple of 16 bytes */
+ unsigned long mas0;
+ unsigned long mas1;
+ unsigned long mas2;
+ unsigned long mas3;
+ unsigned long mas6;
+ unsigned long mas7;
+ unsigned long srr0;
+ unsigned long srr1;
+ unsigned long csrr0;
+ unsigned long csrr1;
+ unsigned long dsrr0;
+ unsigned long dsrr1;
+ };
+#endif
};
#endif
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index a47eefa09bcb..5bee245d832b 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -309,24 +309,21 @@ int main(void)
STACK_PT_REGS_OFFSET(STACK_REGS_IAMR, iamr);
#endif
-#if defined(CONFIG_PPC32)
-#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
- DEFINE(EXC_LVL_SIZE, STACK_EXC_LVL_FRAME_SIZE);
- DEFINE(MAS0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
+#if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
+ STACK_PT_REGS_OFFSET(MAS0, mas0);
/* we overload MMUCR for 44x on MAS0 since they are mutually exclusive */
- DEFINE(MMUCR, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
- DEFINE(MAS1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas1));
- DEFINE(MAS2, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas2));
- DEFINE(MAS3, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas3));
- DEFINE(MAS6, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas6));
- DEFINE(MAS7, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas7));
- DEFINE(_SRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr0));
- DEFINE(_SRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr1));
- DEFINE(_CSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr0));
- DEFINE(_CSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr1));
- DEFINE(_DSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr0));
- DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1));
-#endif
+ STACK_PT_REGS_OFFSET(MMUCR, mas0);
+ STACK_PT_REGS_OFFSET(MAS1, mas1);
+ STACK_PT_REGS_OFFSET(MAS2, mas2);
+ STACK_PT_REGS_OFFSET(MAS3, mas3);
+ STACK_PT_REGS_OFFSET(MAS6, mas6);
+ STACK_PT_REGS_OFFSET(MAS7, mas7);
+ STACK_PT_REGS_OFFSET(_SRR0, srr0);
+ STACK_PT_REGS_OFFSET(_SRR1, srr1);
+ STACK_PT_REGS_OFFSET(_CSRR0, csrr0);
+ STACK_PT_REGS_OFFSET(_CSRR1, csrr1);
+ STACK_PT_REGS_OFFSET(_DSRR0, dsrr0);
+ STACK_PT_REGS_OFFSET(_DSRR1, dsrr1);
#endif
/* About the CPU features table */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 87b806e8eded..e5503420b6c6 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -168,20 +168,18 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
/* only on e500mc */
#define DBG_STACK_BASE dbgirq_ctx
-#define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
-
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
slwi r8,r8,2; \
addis r8,r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
- addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
+ addi r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
lis r8,level##_STACK_BASE@ha; \
lwz r8,level##_STACK_BASE@l(r8); \
- addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
+ addi r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
#endif
/*
@@ -208,7 +206,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
mtmsr r11; \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
lwz r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
- addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
+ addi r11,r11,THREAD_SIZE - INT_FRAME_SIZE; /* allocate stack frame */\
beq 1f; \
/* COMING FROM USER MODE */ \
stw r9,_CCR(r11); /* save CR */\
@@ -516,24 +514,5 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
bl kernel_fp_unavailable_exception; \
b interrupt_return
-#else /* __ASSEMBLY__ */
-struct exception_regs {
- unsigned long mas0;
- unsigned long mas1;
- unsigned long mas2;
- unsigned long mas3;
- unsigned long mas6;
- unsigned long mas7;
- unsigned long srr0;
- unsigned long srr1;
- unsigned long csrr0;
- unsigned long csrr1;
- unsigned long dsrr0;
- unsigned long dsrr1;
-};
-
-/* ensure this structure is always sized to a multiple of the stack alignment */
-#define STACK_EXC_LVL_FRAME_SIZE ALIGN(sizeof (struct exception_regs), 16)
-
#endif /* __ASSEMBLY__ */
#endif /* __HEAD_BOOKE_H__ */