| Message ID | 20170719044946.22030-3-benh@kernel.crashing.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d300627c6a53693fb01479b59b0cdd293761b1fa |
| Headers | show |
Benjamin Herrenschmidt <benh@kernel.crashing.org> writes: > On legacy 6xx 32-bit procesors, we checked for the DABR match bit > in DSISR from do_page_fault(), in the middle of a pile of ifdef's > because all other CPU types do it in assembly prior to calling > do_page_fault. Fix that. > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > --- > arch/powerpc/kernel/entry_32.S | 11 +++++++++++ > arch/powerpc/mm/fault.c | 9 --------- > 2 files changed, 11 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S > index 8587059ad848..7331df033804 100644 > --- a/arch/powerpc/kernel/entry_32.S > +++ b/arch/powerpc/kernel/entry_32.S > @@ -586,6 +586,8 @@ ppc_swapcontext: > handle_page_fault: > stw r4,_DAR(r1) > addi r3,r1,STACK_FRAME_OVERHEAD > + andis. r0,r5,DSISR_DABRMATCH@h > + bne- handle_dabr_fault > bl do_page_fault > cmpwi r3,0 > beq+ ret_from_except > @@ -599,6 +601,15 @@ handle_page_fault: > bl bad_page_fault > b ret_from_except_full > > + /* We have a data breakpoint exception - handle it */ > +handle_dabr_fault: > + SAVE_NVGPRS(r1) > + lwz r0,_TRAP(r1) > + clrrwi r0,r0,1 > + stw r0,_TRAP(r1) > + bl do_break > + b ret_from_except_full This breaks ~35% of the defconfigs. eg. ppc44x_defconfig http://kisskb.ellerman.id.au/kisskb/buildresult/13113408/ arch/powerpc/kernel/entry_32.S:(.text+0x7ac): undefined reference to `do_break' For now I've just wrapped the asm above in: +#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || defined(CONFIG_PPC_8xx)) But would be happy if there was something less gross. cheers
On Thu, 2017-08-03 at 10:19 +1000, Michael Ellerman wrote: > arch/powerpc/kernel/entry_32.S:(.text+0x7ac): undefined reference to `do_break' > > For now I've just wrapped the asm above in: > > +#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || defined(CONFIG_PPC_8xx)) > > But would be happy if there was something less gross. #ifdef CONFIG_6xx... Cheers, Ben.
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 8587059ad848..7331df033804 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -586,6 +586,8 @@ ppc_swapcontext: handle_page_fault: stw r4,_DAR(r1) addi r3,r1,STACK_FRAME_OVERHEAD + andis. r0,r5,DSISR_DABRMATCH@h + bne- handle_dabr_fault bl do_page_fault cmpwi r3,0 beq+ ret_from_except @@ -599,6 +601,15 @@ handle_page_fault: bl bad_page_fault b ret_from_except_full + /* We have a data breakpoint exception - handle it */ +handle_dabr_fault: + SAVE_NVGPRS(r1) + lwz r0,_TRAP(r1) + clrrwi r0,r0,1 + stw r0,_TRAP(r1) + bl do_break + b ret_from_except_full + /* * This routine switches between two different tasks. The process * state of one is saved on its kernel stack. Then the state diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index f04bc9f6b134..f257965b54b5 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -242,15 +242,6 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, goto bail; } -#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || \ - defined(CONFIG_PPC_BOOK3S_64) || defined(CONFIG_PPC_8xx)) - if (error_code & DSISR_DABRMATCH) { - /* breakpoint match */ - do_break(regs, address, error_code); - goto bail; - } -#endif - /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable();
On legacy 6xx 32-bit procesors, we checked for the DABR match bit in DSISR from do_page_fault(), in the middle of a pile of ifdef's because all other CPU types do it in assembly prior to calling do_page_fault. Fix that. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/kernel/entry_32.S | 11 +++++++++++ arch/powerpc/mm/fault.c | 9 --------- 2 files changed, 11 insertions(+), 9 deletions(-)