From 9141300a5884b57cea6d32c4e3fd16a337cfc99a Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Sun, 6 Apr 2014 23:04:12 +0100 Subject: [PATCH] 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: Catalin Marinas --- arch/arm64/include/asm/esr.h | 6 ++++-- arch/arm64/include/asm/processor.h | 1 + arch/arm64/kernel/signal32.c | 7 ++++++- arch/arm64/kernel/traps.c | 7 +++++-- arch/arm64/mm/fault.c | 8 ++++---- 5 files changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index c4a7f940b387..72674f4c3871 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -18,9 +18,11 @@ #ifndef __ASM_ESR_H #define __ASM_ESR_H -#define ESR_EL1_EC_SHIFT (26) -#define ESR_EL1_IL (1U << 25) +#define ESR_EL1_WRITE (1 << 6) +#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_WFI (0x01) #define ESR_EL1_EC_CP15_32 (0x03) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 45b20cd6cbca..34de2a8f7d93 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -79,6 +79,7 @@ struct thread_struct { unsigned long tp_value; struct fpsimd_state fpsimd_state; unsigned long fault_address; /* fault info */ + unsigned long fault_code; /* ESR_EL1 value */ struct debug_info debug; /* debugging */ }; diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index b3fc9f5ec6d3..050c1c2af777 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -23,6 +23,7 @@ #include #include +#include #include #include #include @@ -81,6 +82,8 @@ struct compat_vfp_sigframe { #define VFP_MAGIC 0x56465001 #define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe) +#define FSR_WRITE_SHIFT (11) + struct compat_aux_sigframe { 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((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(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 7ffadddb645d..c43cfa9b8304 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -251,10 +251,13 @@ void die(const char *str, struct pt_regs *regs, int err) void arm64_notify_die(const char *str, struct pt_regs *regs, 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); - else + } else { die(str, regs, err); + } } asmlinkage void __exception do_undefinstr(struct pt_regs *regs) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index c23751b06120..bcc965e2cce1 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -32,6 +32,7 @@ #include #include +#include #include #include #include @@ -123,6 +124,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr, } tsk->thread.fault_address = addr; + tsk->thread.fault_code = esr; si.si_signo = sig; si.si_errno = 0; 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_BADACCESS 0x020000 -#define ESR_WRITE (1 << 6) -#define ESR_CM (1 << 8) #define ESR_LNX_EXEC (1 << 24) 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) { 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; mm_flags |= FAULT_FLAG_WRITE; } @@ -525,7 +525,7 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, info.si_errno = 0; info.si_code = inf->code; info.si_addr = (void __user *)addr; - arm64_notify_die("", regs, &info, esr); + arm64_notify_die("", regs, &info, 0); return 0; } -- 2.20.1