On Thu, Oct 07, 2010 at 04:57:21AM +0800, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> An earlier patch fixed the hwpoison fault handling to encode the
> huge page size in the fault code of the page fault handler.
>
> This is needed to report this information in SIGBUS to user space.
>
> This is a straight forward patch to pass this information
> through to the signal handling in the x86 specific fault.c
>
> Cc: x86@xxxxxxxxxx
> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Cc: fengguang.wu@xxxxxxxxx
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> ---
> arch/x86/mm/fault.c | 19 +++++++++++++------
> 1 files changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
> index 4c4508e..1d15a27 100644
> --- a/arch/x86/mm/fault.c
> +++ b/arch/x86/mm/fault.c
> @@ -11,6 +11,7 @@
> #include <linux/kprobes.h> /* __kprobes, ... */
> #include <linux/mmiotrace.h> /* kmmio_handler, ... */
> #include <linux/perf_event.h> /* perf_sw_event */
> +#include <linux/hugetlb.h> /* hstate_index_to_shift */
>
> #include <asm/traps.h> /* dotraplinkage, ... */
> #include <asm/pgalloc.h> /* pgd_*(), ... */
> @@ -160,15 +161,20 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
>
> static void
> force_sig_info_fault(int si_signo, int si_code, unsigned long address,
> - struct task_struct *tsk)
> + struct task_struct *tsk, int fault)
> {
> + unsigned lsb = 0;
> siginfo_t info;
>
> info.si_signo = si_signo;
> info.si_errno = 0;
> info.si_code = si_code;
> info.si_addr = (void __user *)address;
> - info.si_addr_lsb = si_code == BUS_MCEERR_AR ? PAGE_SHIFT : 0;
Ah you changed the conditional 0..
> + if (fault & VM_FAULT_HWPOISON_LARGE)
> + lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
> + if (fault & VM_FAULT_HWPOISON)
> + lsb = PAGE_SHIFT;
> + info.si_addr_lsb = lsb;
>
> force_sig_info(si_signo, &info, tsk);
> }
> @@ -731,7 +737,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
> tsk->thread.error_code = error_code | (address >= TASK_SIZE);
> tsk->thread.trap_no = 14;
>
> - force_sig_info_fault(SIGSEGV, si_code, address, tsk);
> + force_sig_info_fault(SIGSEGV, si_code, address, tsk, 0);
..and it's sure reasonable.
Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Thanks,
Fengguang
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