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-rw-r--r--arch/arm64/include/asm/exception.h2
-rw-r--r--arch/arm64/include/asm/signal.h25
-rw-r--r--arch/arm64/include/asm/system_misc.h2
-rw-r--r--arch/arm64/include/asm/traps.h6
-rw-r--r--arch/arm64/kernel/debug-monitors.c5
-rw-r--r--arch/arm64/kernel/entry-common.c2
-rw-r--r--arch/arm64/kernel/ptrace.c7
-rw-r--r--arch/arm64/kernel/sys_compat.c5
-rw-r--r--arch/arm64/kernel/traps.c29
-rw-r--r--arch/arm64/mm/fault.c83
10 files changed, 101 insertions, 65 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 99b9383cd036..2a8aa1884d8a 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -32,7 +32,7 @@ static inline u32 disr_to_esr(u64 disr)
}
asmlinkage void enter_from_user_mode(void);
-void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
+void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs);
void do_undefinstr(struct pt_regs *regs);
void do_bti(struct pt_regs *regs);
asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr);
diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h
new file mode 100644
index 000000000000..ef449f5f4ba8
--- /dev/null
+++ b/arch/arm64/include/asm/signal.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARM64_ASM_SIGNAL_H
+#define __ARM64_ASM_SIGNAL_H
+
+#include <asm/memory.h>
+#include <uapi/asm/signal.h>
+#include <uapi/asm/siginfo.h>
+
+static inline void __user *arch_untagged_si_addr(void __user *addr,
+ unsigned long sig,
+ unsigned long si_code)
+{
+ /*
+ * For historical reasons, all bits of the fault address are exposed as
+ * address bits for watchpoint exceptions. New architectures should
+ * handle the tag bits consistently.
+ */
+ if (sig == SIGTRAP && si_code == TRAP_BRKPT)
+ return addr;
+
+ return untagged_addr(addr);
+}
+#define arch_untagged_si_addr arch_untagged_si_addr
+
+#endif
diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h
index 1ab63cfbbaf1..673be2d1263c 100644
--- a/arch/arm64/include/asm/system_misc.h
+++ b/arch/arm64/include/asm/system_misc.h
@@ -22,7 +22,7 @@ void die(const char *msg, struct pt_regs *regs, int err);
struct siginfo;
void arm64_notify_die(const char *str, struct pt_regs *regs,
- int signo, int sicode, void __user *addr,
+ int signo, int sicode, unsigned long far,
int err);
void hook_debug_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index d96dc2c7c09d..54f32a0675df 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -26,9 +26,9 @@ void register_undef_hook(struct undef_hook *hook);
void unregister_undef_hook(struct undef_hook *hook);
void force_signal_inject(int signal, int code, unsigned long address, unsigned int err);
void arm64_notify_segfault(unsigned long addr);
-void arm64_force_sig_fault(int signo, int code, void __user *addr, const char *str);
-void arm64_force_sig_mceerr(int code, void __user *addr, short lsb, const char *str);
-void arm64_force_sig_ptrace_errno_trap(int errno, void __user *addr, const char *str);
+void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str);
+void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str);
+void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str);
/*
* Move regs->pc to next instruction and do necessary setup before it
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index fa76151de6ff..4f3661eeb7ec 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -234,9 +234,8 @@ static void send_user_sigtrap(int si_code)
if (interrupts_enabled(regs))
local_irq_enable();
- arm64_force_sig_fault(SIGTRAP, si_code,
- (void __user *)instruction_pointer(regs),
- "User debug trap");
+ arm64_force_sig_fault(SIGTRAP, si_code, instruction_pointer(regs),
+ "User debug trap");
}
static int single_step_handler(unsigned long unused, unsigned int esr,
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 43d4c329775f..dbbddfbf4a72 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -22,7 +22,6 @@ static void notrace el1_abort(struct pt_regs *regs, unsigned long esr)
unsigned long far = read_sysreg(far_el1);
local_daif_inherit(regs);
- far = untagged_addr(far);
do_mem_abort(far, esr, regs);
}
NOKPROBE_SYMBOL(el1_abort);
@@ -114,7 +113,6 @@ static void notrace el0_da(struct pt_regs *regs, unsigned long esr)
user_exit_irqoff();
local_daif_restore(DAIF_PROCCTX);
- far = untagged_addr(far);
do_mem_abort(far, esr, regs);
}
NOKPROBE_SYMBOL(el0_da);
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index f49b349e16a3..8ac487c84e37 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -192,14 +192,11 @@ static void ptrace_hbptriggered(struct perf_event *bp,
break;
}
}
- arm64_force_sig_ptrace_errno_trap(si_errno,
- (void __user *)bkpt->trigger,
+ arm64_force_sig_ptrace_errno_trap(si_errno, bkpt->trigger,
desc);
}
#endif
- arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT,
- (void __user *)(bkpt->trigger),
- desc);
+ arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT, bkpt->trigger, desc);
}
/*
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 3c18c2454089..265fe3eb1069 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -68,7 +68,7 @@ do_compat_cache_op(unsigned long start, unsigned long end, int flags)
*/
long compat_arm_syscall(struct pt_regs *regs, int scno)
{
- void __user *addr;
+ unsigned long addr;
switch (scno) {
/*
@@ -111,8 +111,7 @@ long compat_arm_syscall(struct pt_regs *regs, int scno)
break;
}
- addr = (void __user *)instruction_pointer(regs) -
- (compat_thumb_mode(regs) ? 2 : 4);
+ addr = instruction_pointer(regs) - (compat_thumb_mode(regs) ? 2 : 4);
arm64_notify_die("Oops - bad compat syscall(2)", regs,
SIGILL, ILL_ILLTRP, addr, scno);
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8af4e0e85736..f4ddbe9ed3f1 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -170,32 +170,32 @@ static void arm64_show_signal(int signo, const char *str)
__show_regs(regs);
}
-void arm64_force_sig_fault(int signo, int code, void __user *addr,
+void arm64_force_sig_fault(int signo, int code, unsigned long far,
const char *str)
{
arm64_show_signal(signo, str);
if (signo == SIGKILL)
force_sig(SIGKILL);
else
- force_sig_fault(signo, code, addr);
+ force_sig_fault(signo, code, (void __user *)far);
}
-void arm64_force_sig_mceerr(int code, void __user *addr, short lsb,
+void arm64_force_sig_mceerr(int code, unsigned long far, short lsb,
const char *str)
{
arm64_show_signal(SIGBUS, str);
- force_sig_mceerr(code, addr, lsb);
+ force_sig_mceerr(code, (void __user *)far, lsb);
}
-void arm64_force_sig_ptrace_errno_trap(int errno, void __user *addr,
+void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far,
const char *str)
{
arm64_show_signal(SIGTRAP, str);
- force_sig_ptrace_errno_trap(errno, addr);
+ force_sig_ptrace_errno_trap(errno, (void __user *)far);
}
void arm64_notify_die(const char *str, struct pt_regs *regs,
- int signo, int sicode, void __user *addr,
+ int signo, int sicode, unsigned long far,
int err)
{
if (user_mode(regs)) {
@@ -203,7 +203,7 @@ void arm64_notify_die(const char *str, struct pt_regs *regs,
current->thread.fault_address = 0;
current->thread.fault_code = err;
- arm64_force_sig_fault(signo, sicode, addr, str);
+ arm64_force_sig_fault(signo, sicode, far, str);
} else {
die(str, regs, err);
}
@@ -374,7 +374,7 @@ void force_signal_inject(int signal, int code, unsigned long address, unsigned i
signal = SIGKILL;
}
- arm64_notify_die(desc, regs, signal, code, (void __user *)address, err);
+ arm64_notify_die(desc, regs, signal, code, address, err);
}
/*
@@ -385,7 +385,7 @@ void arm64_notify_segfault(unsigned long addr)
int code;
mmap_read_lock(current->mm);
- if (find_vma(current->mm, addr) == NULL)
+ if (find_vma(current->mm, untagged_addr(addr)) == NULL)
code = SEGV_MAPERR;
else
code = SEGV_ACCERR;
@@ -448,12 +448,13 @@ NOKPROBE_SYMBOL(do_ptrauth_fault);
static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
{
- unsigned long address;
+ unsigned long tagged_address, address;
int rt = ESR_ELx_SYS64_ISS_RT(esr);
int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT;
int ret = 0;
- address = untagged_addr(pt_regs_read_reg(regs, rt));
+ tagged_address = pt_regs_read_reg(regs, rt);
+ address = untagged_addr(tagged_address);
switch (crm) {
case ESR_ELx_SYS64_ISS_CRM_DC_CVAU: /* DC CVAU, gets promoted */
@@ -480,7 +481,7 @@ static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
}
if (ret)
- arm64_notify_segfault(address);
+ arm64_notify_segfault(tagged_address);
else
arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
}
@@ -772,7 +773,7 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
*/
void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
{
- void __user *pc = (void __user *)instruction_pointer(regs);
+ unsigned long pc = instruction_pointer(regs);
current->thread.fault_address = 0;
current->thread.fault_code = esr;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 1ee94002801f..29a6b8c9e830 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -40,7 +40,7 @@
#include <asm/traps.h>
struct fault_info {
- int (*fn)(unsigned long addr, unsigned int esr,
+ int (*fn)(unsigned long far, unsigned int esr,
struct pt_regs *regs);
int sig;
int code;
@@ -385,8 +385,11 @@ static void set_thread_esr(unsigned long address, unsigned int esr)
current->thread.fault_code = esr;
}
-static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static void do_bad_area(unsigned long far, unsigned int esr,
+ struct pt_regs *regs)
{
+ unsigned long addr = untagged_addr(far);
+
/*
* If we are in kernel mode at this point, we have no context to
* handle this fault with.
@@ -395,8 +398,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
const struct fault_info *inf = esr_to_fault_info(esr);
set_thread_esr(addr, esr);
- arm64_force_sig_fault(inf->sig, inf->code, (void __user *)addr,
- inf->name);
+ arm64_force_sig_fault(inf->sig, inf->code, far, inf->name);
} else {
__do_kernel_fault(addr, esr, regs);
}
@@ -448,7 +450,7 @@ static bool is_write_abort(unsigned int esr)
return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
}
-static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
+static int __kprobes do_page_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
const struct fault_info *inf;
@@ -456,6 +458,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
vm_fault_t fault;
unsigned long vm_flags = VM_ACCESS_FLAGS;
unsigned int mm_flags = FAULT_FLAG_DEFAULT;
+ unsigned long addr = untagged_addr(far);
if (kprobe_page_fault(regs, esr))
return 0;
@@ -567,8 +570,7 @@ retry:
* We had some memory, but were unable to successfully fix up
* this page fault.
*/
- arm64_force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr,
- inf->name);
+ arm64_force_sig_fault(SIGBUS, BUS_ADRERR, far, inf->name);
} else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
unsigned int lsb;
@@ -576,8 +578,7 @@ retry:
if (fault & VM_FAULT_HWPOISON_LARGE)
lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
- arm64_force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, lsb,
- inf->name);
+ arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
@@ -585,8 +586,7 @@ retry:
*/
arm64_force_sig_fault(SIGSEGV,
fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
- (void __user *)addr,
- inf->name);
+ far, inf->name);
}
return 0;
@@ -596,33 +596,35 @@ no_context:
return 0;
}
-static int __kprobes do_translation_fault(unsigned long addr,
+static int __kprobes do_translation_fault(unsigned long far,
unsigned int esr,
struct pt_regs *regs)
{
+ unsigned long addr = untagged_addr(far);
+
if (is_ttbr0_addr(addr))
- return do_page_fault(addr, esr, regs);
+ return do_page_fault(far, esr, regs);
- do_bad_area(addr, esr, regs);
+ do_bad_area(far, esr, regs);
return 0;
}
-static int do_alignment_fault(unsigned long addr, unsigned int esr,
+static int do_alignment_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
- do_bad_area(addr, esr, regs);
+ do_bad_area(far, esr, regs);
return 0;
}
-static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static int do_bad(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
return 1; /* "fault" */
}
-static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+static int do_sea(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
const struct fault_info *inf;
- void __user *siaddr;
+ unsigned long siaddr;
inf = esr_to_fault_info(esr);
@@ -634,19 +636,30 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
return 0;
}
- if (esr & ESR_ELx_FnV)
- siaddr = NULL;
- else
- siaddr = (void __user *)addr;
+ if (esr & ESR_ELx_FnV) {
+ siaddr = 0;
+ } else {
+ /*
+ * The architecture specifies that the tag bits of FAR_EL1 are
+ * UNKNOWN for synchronous external aborts. Mask them out now
+ * so that userspace doesn't see them.
+ */
+ siaddr = untagged_addr(far);
+ }
arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
return 0;
}
-static int do_tag_check_fault(unsigned long addr, unsigned int esr,
+static int do_tag_check_fault(unsigned long far, unsigned int esr,
struct pt_regs *regs)
{
- do_bad_area(addr, esr, regs);
+ /*
+ * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN for tag
+ * check faults. Mask them out now so that userspace doesn't see them.
+ */
+ far &= (1UL << 60) - 1;
+ do_bad_area(far, esr, regs);
return 0;
}
@@ -717,11 +730,12 @@ static const struct fault_info fault_info[] = {
{ do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
};
-void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs)
{
const struct fault_info *inf = esr_to_fault_info(esr);
+ unsigned long addr = untagged_addr(far);
- if (!inf->fn(addr, esr, regs))
+ if (!inf->fn(far, esr, regs))
return;
if (!user_mode(regs)) {
@@ -730,8 +744,12 @@ void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
show_pte(addr);
}
- arm64_notify_die(inf->name, regs,
- inf->sig, inf->code, (void __user *)addr, esr);
+ /*
+ * At this point we have an unrecognized fault type whose tag bits may
+ * have been defined as UNKNOWN. Therefore we only expose the untagged
+ * address to the signal handler.
+ */
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, addr, esr);
}
NOKPROBE_SYMBOL(do_mem_abort);
@@ -744,8 +762,8 @@ NOKPROBE_SYMBOL(do_el0_irq_bp_hardening);
void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
- arm64_notify_die("SP/PC alignment exception", regs,
- SIGBUS, BUS_ADRALN, (void __user *)addr, esr);
+ arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN,
+ addr, esr);
}
NOKPROBE_SYMBOL(do_sp_pc_abort);
@@ -871,8 +889,7 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
arm64_apply_bp_hardening();
if (inf->fn(addr_if_watchpoint, esr, regs)) {
- arm64_notify_die(inf->name, regs,
- inf->sig, inf->code, (void __user *)pc, esr);
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, pc, esr);
}
debug_exception_exit(regs);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 09:28:43 +0000