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Commit 9141300a authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Provide read/write fault information in compat signal handlers 



For AArch32, bit 11 (WnR) of the FSR/ESR register is set when the fault
was caused by a write access and applications like Qemu rely on such
information being provided in sigcontext. This patch introduces the
ESR_EL1 tracking for the arm64 kernel faults and sets bit 11 accordingly
in compat sigcontext.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 64001113

arch/arm64/include/asm/esr.h

+4 −2
Original line number Original line Diff line number Diff line
@@ -18,9 +18,11 @@ 
#ifndef __ASM_ESR_H

#ifndef __ASM_ESR_H

#define __ASM_ESR_H

#define __ASM_ESR_H





#define ESR_EL1_EC_SHIFT	(26)

#define ESR_EL1_WRITE		(1 << 6)

#define ESR_EL1_IL		(1U << 25)

#define ESR_EL1_CM		(1 << 8)

#define ESR_EL1_IL		(1 << 25)





#define ESR_EL1_EC_SHIFT	(26)

#define ESR_EL1_EC_UNKNOWN	(0x00)

#define ESR_EL1_EC_UNKNOWN	(0x00)

#define ESR_EL1_EC_WFI		(0x01)

#define ESR_EL1_EC_WFI		(0x01)

#define ESR_EL1_EC_CP15_32	(0x03)

#define ESR_EL1_EC_CP15_32	(0x03)

arch/arm64/include/asm/processor.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -79,6 +79,7 @@ struct thread_struct { 
	unsigned long		tp_value;

	unsigned long		tp_value;

	struct fpsimd_state	fpsimd_state;

	struct fpsimd_state	fpsimd_state;

	unsigned long		fault_address;	/* fault info */

	unsigned long		fault_address;	/* fault info */

	unsigned long		fault_code;	/* ESR_EL1 value */

	struct debug_info	debug;		/* debugging */

	struct debug_info	debug;		/* debugging */

};

};

arch/arm64/kernel/signal32.c

+6 −1
Original line number Original line Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/syscalls.h>

#include <linux/syscalls.h>

#include <linux/ratelimit.h>

#include <linux/ratelimit.h>





#include <asm/esr.h>

#include <asm/fpsimd.h>

#include <asm/fpsimd.h>

#include <asm/signal32.h>

#include <asm/signal32.h>

#include <asm/uaccess.h>

#include <asm/uaccess.h>
@@ -81,6 +82,8 @@ struct compat_vfp_sigframe { 
#define VFP_MAGIC		0x56465001

#define VFP_MAGIC		0x56465001

#define VFP_STORAGE_SIZE	sizeof(struct compat_vfp_sigframe)

#define VFP_STORAGE_SIZE	sizeof(struct compat_vfp_sigframe)





#define FSR_WRITE_SHIFT		(11)



struct compat_aux_sigframe {

struct compat_aux_sigframe {

	struct compat_vfp_sigframe	vfp;

	struct compat_vfp_sigframe	vfp;
@@ -500,7 +503,9 @@ static int compat_setup_sigframe(struct compat_sigframe __user *sf, 
	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);

	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);





	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);

	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);

	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);

	/* set the compat FSR WnR */

	__put_user_error(!!(current->thread.fault_code & ESR_EL1_WRITE) <<

			 FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);

	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);

	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);

	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);

	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);

arch/arm64/kernel/traps.c

+5 −2
Original line number Original line Diff line number Diff line
@@ -251,11 +251,14 @@ void die(const char *str, struct pt_regs *regs, int err) 
void arm64_notify_die(const char *str, struct pt_regs *regs,

void arm64_notify_die(const char *str, struct pt_regs *regs,

		      struct siginfo *info, int err)

		      struct siginfo *info, int err)

{

{

	if (user_mode(regs))

	if (user_mode(regs)) {

		current->thread.fault_address = 0;

		current->thread.fault_code = err;

		force_sig_info(info->si_signo, info, current);

		force_sig_info(info->si_signo, info, current);

	else

	} else {

		die(str, regs, err);

		die(str, regs, err);

	}

	}

}





asmlinkage void __exception do_undefinstr(struct pt_regs *regs)

asmlinkage void __exception do_undefinstr(struct pt_regs *regs)

{

{

arch/arm64/mm/fault.c

+4 −4
Original line number Original line Diff line number Diff line
@@ -32,6 +32,7 @@ 




#include <asm/exception.h>

#include <asm/exception.h>

#include <asm/debug-monitors.h>

#include <asm/debug-monitors.h>

#include <asm/esr.h>

#include <asm/system_misc.h>

#include <asm/system_misc.h>

#include <asm/pgtable.h>

#include <asm/pgtable.h>

#include <asm/tlbflush.h>

#include <asm/tlbflush.h>
@@ -123,6 +124,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, 
	}

	}





	tsk->thread.fault_address = addr;

	tsk->thread.fault_address = addr;

	tsk->thread.fault_code = esr;

	si.si_signo = sig;

	si.si_signo = sig;

	si.si_errno = 0;

	si.si_errno = 0;

	si.si_code = code;

	si.si_code = code;
@@ -148,8 +150,6 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re 
#define VM_FAULT_BADMAP		0x010000

#define VM_FAULT_BADMAP		0x010000

#define VM_FAULT_BADACCESS	0x020000

#define VM_FAULT_BADACCESS	0x020000





#define ESR_WRITE		(1 << 6)

#define ESR_CM			(1 << 8)

#define ESR_LNX_EXEC		(1 << 24)

#define ESR_LNX_EXEC		(1 << 24)





static int __do_page_fault(struct mm_struct *mm, unsigned long addr,

static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
@@ -218,7 +218,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, 




	if (esr & ESR_LNX_EXEC) {

	if (esr & ESR_LNX_EXEC) {

		vm_flags = VM_EXEC;

		vm_flags = VM_EXEC;

	} else if ((esr & ESR_WRITE) && !(esr & ESR_CM)) {

	} else if ((esr & ESR_EL1_WRITE) && !(esr & ESR_EL1_CM)) {

		vm_flags = VM_WRITE;

		vm_flags = VM_WRITE;

		mm_flags |= FAULT_FLAG_WRITE;

		mm_flags |= FAULT_FLAG_WRITE;

	}

	}
@@ -525,7 +525,7 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, 
	info.si_errno = 0;

	info.si_errno = 0;

	info.si_code  = inf->code;

	info.si_code  = inf->code;

	info.si_addr  = (void __user *)addr;

	info.si_addr  = (void __user *)addr;

	arm64_notify_die("", regs, &info, esr);

	arm64_notify_die("", regs, &info, 0);





	return 0;

	return 0;

}
 
}