Le 10/11/2020 à 09:29, Nicholas Piggin a écrit :
Excerpts from Christophe Leroy's message of November 6, 2020 5:59 pm:
Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
Make mm fault handlers all just take the pt_regs * argument and load
DAR/DSISR from that. Make those that return a value return long.
This is done to make the function signatures match other handlers, which
will help with a future patch to add wrappers. Explicit arguments could
be added for performance but that would require more wrapper macro
variants.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
[...]
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index e65a49f246ef..390a296b16a3 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -549,11 +549,12 @@ static int __do_page_fault(struct pt_regs *regs, unsigned
long address,
}
NOKPROBE_SYMBOL(__do_page_fault);
-int do_page_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
+long do_page_fault(struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
- int err;
+ unsigned long address = regs->dar;
+ unsigned long error_code = regs->dsisr;
+ long err;
By doing something more or less like this (need to be tuned for bookE as well):
+ int is_exec = TRAP(regs) == 0x400;
+ unsigned long address = is_exec ? regs->ssr0 : regs->dar;
+ unsigned long error_code = is_exec ? (regs->ssr1 & DSISR_SRR1_MATCH_32S) :
regs->dsisr;
Ah, I didn't see that you saved these in srr0/1 already. Hmm, not in
pt_regs though. thread_struct (VMAP_STACK only)? exception_regs (booke
only)? Doesn't seem so easy.
Oops yes you are right, SRR0/SRR1 are not in pt_regs. And their validity in thread struct is rather
short ... So forget my comment.
Christophe
