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Commit 3913fdd7 authored by Anton Blanchard's avatar Anton Blanchard Committed by Michael Ellerman
Browse files

powerpc: Add VM_FAULT_HWPOISON handling to powerpc page fault handler 



do_page_fault was missing knowledge of HWPOISON, and we would oops
if userspace tried to access a poisoned page:

kernel BUG at arch/powerpc/mm/fault.c:180!

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 63af5262

arch/powerpc/mm/fault.c

+11 −6
Original line number Diff line number Diff line
@@ -114,7 +114,8 @@ static int store_updates_sp(struct pt_regs *regs) 
#define MM_FAULT_CONTINUE	-1

#define MM_FAULT_ERR(sig)	(sig)



static int do_sigbus(struct pt_regs *regs, unsigned long address)

static int do_sigbus(struct pt_regs *regs, unsigned long address,

		     unsigned int fault)

{

	siginfo_t info;
@@ -128,6 +129,13 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address) 
	info.si_errno = 0;

	info.si_code = BUS_ADRERR;

	info.si_addr = (void __user *)address;

#ifdef CONFIG_MEMORY_FAILURE

	if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {

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

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

		info.si_code = BUS_MCEERR_AR;

	}

#endif

	force_sig_info(SIGBUS, &info, current);

	return MM_FAULT_RETURN;

}
@@ -170,11 +178,8 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault) 
		return MM_FAULT_RETURN;

	}



	/* Bus error. x86 handles HWPOISON here, we'll add this if/when

	 * we support the feature in HW

	 */

	if (fault & VM_FAULT_SIGBUS)

		return do_sigbus(regs, addr);

	if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE))

		return do_sigbus(regs, addr, fault);



	/* We don't understand the fault code, this is fatal */

	BUG();