Re: [PATCH 07/10] powerpc/64e/interrupt: handle bad_page_fault in C

[Christophe Leroy]

Le 15/03/2021 à 04:17, Nicholas Piggin a écrit :

With non-volatile registers saved on interrupt, bad_page_fault
can now be called by do_page_fault.

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
  arch/powerpc/kernel/exceptions-64e.S | 6 ------
  arch/powerpc/mm/fault.c              | 5 +----
  2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64e.S 
b/arch/powerpc/kernel/exceptions-64e.S
index a059ab3542c2..b08c84e0fa56 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -937,12 +937,6 @@ storage_fault_common:
        ld      r14,PACA_EXGEN+EX_R14(r13)
        ld      r15,PACA_EXGEN+EX_R15(r13)
        bl      do_page_fault
-       cmpdi   r3,0
-       bne-    1f
-       b       interrupt_return
-       mr      r4,r3
-       addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      __bad_page_fault

Then __bad_page_fault() can be static now.

        b       interrupt_return

/*

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 2e54bac99a22..44833660b21d 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -552,12 +552,9 @@ static long __do_page_fault(struct pt_regs *regs)
        if (likely(entry)) {
                instruction_pointer_set(regs, extable_fixup(entry));
                return 0;
-       } else if (!IS_ENABLED(CONFIG_PPC_BOOK3E_64)) {
+       } else {
                __bad_page_fault(regs, err);
                return 0;
-       } else {
-               /* 32 and 64e handle the bad page fault in asm */
-               return err;
        }
  }
  NOKPROBE_SYMBOL(__do_page_fault);