Commit f672b49b authored by Andi Kleen's avatar Andi Kleen
Browse files

x86: HWPOISON: Report correct address granuality for huge hwpoison faults 



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@kernel.org
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: fengguang.wu@intel.com
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent aa50d3a7

arch/x86/mm/fault.c

+13 −6
Original line number Diff line number Diff line
@@ -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;

	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);



		return;

	}
@@ -816,14 +822,14 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, 
	tsk->thread.trap_no	= 14;



#ifdef CONFIG_MEMORY_FAILURE

	if (fault & VM_FAULT_HWPOISON) {

	if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {

		printk(KERN_ERR

	"MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",

			tsk->comm, tsk->pid, address);

		code = BUS_MCEERR_AR;

	}

#endif

	force_sig_info_fault(SIGBUS, code, address, tsk);

	force_sig_info_fault(SIGBUS, code, address, tsk, fault);

}



static noinline void
@@ -833,7 +839,8 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, 
	if (fault & VM_FAULT_OOM) {

		out_of_memory(regs, error_code, address);

	} else {

		if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON))

		if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|

			     VM_FAULT_HWPOISON_LARGE))

			do_sigbus(regs, error_code, address, fault);

		else

			BUG();

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