[PATCH v3 23/41] powerpc/32: Always save non volatile registers on exception entry
From: Christophe Leroy <hidden>
Date: 2021-03-12 12:51:47
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), ptrace support, the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Oleg Nesterov, Linus Torvalds
In preparation of handling exception entry and exit in C, in order to simplify the handling, always save non volatile registers when entering an exception. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/include/asm/ptrace.h | 6 ++---- arch/powerpc/kernel/entry_32.S | 13 +------------ arch/powerpc/kernel/head_32.h | 3 +-- arch/powerpc/kernel/head_booke.h | 2 +- 4 files changed, 5 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 1499e928ea6a..1aca5fe79285 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h@@ -209,16 +209,14 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) */ #define TRAP_FLAGS_MASK 0x1F #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) -#define FULL_REGS(regs) (((regs)->trap & 1) == 0) -#define SET_FULL_REGS(regs) ((regs)->trap &= ~1) +#define FULL_REGS(regs) true +#define SET_FULL_REGS(regs) do { } while (0) #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) #define NV_REG_POISON 0xdeadbeef #define CHECK_FULL_REGS(regs) \ do { \ - if ((regs)->trap & 1) \ - printk(KERN_CRIT "%s: partial register set\n", __func__); \ } while (0) #endif /* __powerpc64__ */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index fb849ef922fb..7084289994b3 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S@@ -81,12 +81,12 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler) */ .globl transfer_to_handler_full transfer_to_handler_full: - SAVE_NVGPRS(r11) _ASM_NOKPROBE_SYMBOL(transfer_to_handler_full) /* fall through */ .globl transfer_to_handler transfer_to_handler: + SAVE_NVGPRS(r11) stw r2,GPR2(r11) stw r12,_NIP(r11) stw r9,_MSR(r11)
@@ -234,10 +234,6 @@ handle_page_fault: bl do_page_fault cmpwi r3,0 beq+ ret_from_except - SAVE_NVGPRS(r1) - lwz r0,_TRAP(r1) - clrrwi r0,r0,1 - stw r0,_TRAP(r1) mr r4,r3 /* err arg for bad_page_fault */ addi r3,r1,STACK_FRAME_OVERHEAD bl __bad_page_fault
@@ -810,13 +806,6 @@ recheck: do_user_signal: /* r10 contains MSR_KERNEL here */ ori r10,r10,MSR_EE mtmsr r10 /* hard-enable interrupts */ - /* save r13-r31 in the exception frame, if not already done */ - lwz r3,_TRAP(r1) - andi. r0,r3,1 - beq 2f - SAVE_NVGPRS(r1) - rlwinm r3,r3,0,0,30 - stw r3,_TRAP(r1) 2: addi r3,r1,STACK_FRAME_OVERHEAD mr r4,r9 bl do_notify_resume
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index e09585b88ba7..087445e45489 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h@@ -198,7 +198,7 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) ret_from_except_full) #define EXC_XFER_LITE(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \ + EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler, \ ret_from_except) .macro vmap_stack_overflow_exception
@@ -215,7 +215,6 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) lwz r1, emergency_ctx@l(r1) addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE EXCEPTION_PROLOG_2 vmap_stack_overflow - SAVE_NVGPRS(r11) addi r3, r1, STACK_FRAME_OVERHEAD EXC_XFER_STD(0, stack_overflow_exception) .endm
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 3707f49f0b78..b31bf9e833c0 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h@@ -331,7 +331,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) ret_from_except_full) #define EXC_XFER_LITE(n, hdlr) \ - EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \ + EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler, \ ret_from_except) /* Check for a single step debug exception while in an exception
--
2.25.0