Commit e7c600f1 authored by Jonathan (Zhixiong) Zhang's avatar Jonathan (Zhixiong) Zhang Committed by Will Deacon
Browse files

arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling 



Add VM_FAULT_HWPOISON[_LARGE] handling to the arm64 page fault
handler. Handling of VM_FAULT_HWPOISON[_LARGE] is very similar
to VM_FAULT_OOM, the only difference is that a different si_code
(BUS_MCEERR_AR) is passed to user space and si_addr_lsb field is
initialized.

Signed-off-by: default avatarJonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
(fix new __do_user_fault call-site)
Signed-off-by: default avatarPunit Agrawal <punit.agrawal@arm.com>
Acked-by: default avatarSteve Capper <steve.capper@arm.com>
Tested-by: default avatarManoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent f02ab08a

arch/arm64/mm/fault.c

+19 −3
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/highmem.h>

#include <linux/perf_event.h>

#include <linux/preempt.h>

#include <linux/hugetlb.h>



#include <asm/bug.h>

#include <asm/cpufeature.h>
@@ -256,10 +257,11 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr, 
 */

static void __do_user_fault(struct task_struct *tsk, unsigned long addr,

			    unsigned int esr, unsigned int sig, int code,

			    struct pt_regs *regs)

			    struct pt_regs *regs, int fault)

{

	struct siginfo si;

	const struct fault_info *inf;

	unsigned int lsb = 0;



	if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) {

		inf = esr_to_fault_info(esr);
@@ -277,6 +279,17 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, 
	si.si_errno = 0;

	si.si_code = code;

	si.si_addr = (void __user *)addr;

	/*

	 * Either small page or large page may be poisoned.

	 * In other words, VM_FAULT_HWPOISON_LARGE and

	 * VM_FAULT_HWPOISON are mutually exclusive.

	 */

	if (fault & VM_FAULT_HWPOISON_LARGE)

		lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));

	else if (fault & VM_FAULT_HWPOISON)

		lsb = PAGE_SHIFT;

	si.si_addr_lsb = lsb;



	force_sig_info(sig, &si, tsk);

}
@@ -291,7 +304,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re 
	 */

	if (user_mode(regs)) {

		inf = esr_to_fault_info(esr);

		__do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs);

		__do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs, 0);

	} else

		__do_kernel_fault(addr, esr, regs);

}
@@ -478,6 +491,9 @@ retry: 
		 */

		sig = SIGBUS;

		code = BUS_ADRERR;

	} else if (fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) {

		sig = SIGBUS;

		code = BUS_MCEERR_AR;

	} else {

		/*

		 * Something tried to access memory that isn't in our memory
@@ -488,7 +504,7 @@ retry: 
			SEGV_ACCERR : SEGV_MAPERR;

	}



	__do_user_fault(tsk, addr, esr, sig, code, regs);

	__do_user_fault(tsk, addr, esr, sig, code, regs, fault);

	return 0;



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