Benjamin Herrenschmidt <b...@kernel.crashing.org> writes: > On Thu, 2013-09-05 at 17:18 +0530, Aneesh Kumar K.V wrote: >> Paul Mackerras <pau...@samba.org> writes: >> >> > On Thu, Sep 05, 2013 at 12:47:02PM +0530, Aneesh Kumar K.V wrote: >> > >> >> @@ -280,6 +280,13 @@ int __kprobes do_page_fault(struct pt_regs *regs, >> >> unsigned long address, >> >> >> >> perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); >> >> >> >> + /* >> >> + * We want to do this outside mmap_sem, because reading code around nip >> >> + * can result in fault, which will cause a deadlock when called with >> >> + * mmap_sem held >> >> + */ >> >> + store_update = store_updates_sp(regs); >> > >> > We should only call store_updates_sp() if user_mode(regs); that was >> > the previous behaviour. >> >> Updated to >> >> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c >> index 8726779..fad7af6 100644 >> --- a/arch/powerpc/mm/fault.c >> +++ b/arch/powerpc/mm/fault.c >> @@ -206,7 +206,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, >> unsigned long address, >> int trap = TRAP(regs); >> int is_exec = trap == 0x400; >> int fault; >> - int rc = 0; >> + int rc = 0, store_update = 0; > > Keep the "sp", in the name, it's confusing otherwise. It's not just > about "store update", it's about specifically recognizing instructions > used to update the stack frame in order to let them and only them > significantly lower the stack pointer. >
Ok will do that. I posted a v2. So will wait for other feedback before i post a new version. -aneesh _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
