Messages in this thread Patch in this message |  | | Date | Tue, 29 Oct 2013 16:40:06 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH v2 03/13] uprobes: allow arch access to xol slot |
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On 10/22, David Long wrote: > > On 10/19/13 12:36, Oleg Nesterov wrote: >> >> How about >> >> void __weak arch_uprobe_xol_copy(...) >> { >> copy_to_page(...); >> } >> >> then just >> >> - copy_to_page(...); >> + arch_uprobe_xol_copy(...); >> >> ? >> > > I was trying to avoid duplicating the VM calls in the > architecture-specific implementations,
Yes, I understand... But this uglifies the generic code.
> but maybe that is the cleaner way > to do it after all. I've made changes as suggested above.
Thanks. and this uglifies arm code I guess ;)
David. Perhaps we can avoid the new hook altogether? What if we do the simple change below (it ignores powerpc) ?
Then arm can add "unsigned long ixol[2]" into its arch_uprobe, and arch_uprobe_analyze_insn() can initialize this member correctly.
What do you think?
Oleg.
--- x/arch/x86/include/asm/uprobes.h +++ x/arch/x86/include/asm/uprobes.h @@ -35,7 +35,10 @@ typedef u8 uprobe_opcode_t; struct arch_uprobe { u16 fixups; - u8 insn[MAX_UINSN_BYTES]; + union { + u8 insn[MAX_UINSN_BYTES]; + u8 ixol[MAX_UINSN_BYTES]; + } #ifdef CONFIG_X86_64 unsigned long rip_rela_target_address; #endif --- x/kernel/events/uprobes.c +++ x/kernel/events/uprobes.c @@ -1264,7 +1264,8 @@ static unsigned long xol_get_insn_slot(s return 0; /* Initialize the slot */ - copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES); + copy_to_page(area->page, xol_vaddr, + uprobe->arch.ixol, sizeof(uprobe->arch.ixol)); /* * We probably need flush_icache_user_range() but it needs vma. * This should work on supported architectures too.
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