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Diffstat (limited to 'arch/arm/kernel/traps.c')
-rw-r--r--arch/arm/kernel/traps.c349
1 files changed, 235 insertions, 114 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 446aee97436..abd2fc06773 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -21,21 +21,30 @@
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/kexec.h>
+#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/sched.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <asm/cacheflush.h>
-#include <asm/system.h>
+#include <asm/exception.h>
#include <asm/unistd.h>
#include <asm/traps.h>
#include <asm/unwind.h>
#include <asm/tls.h>
+#include <asm/system_misc.h>
+#include <asm/opcodes.h>
+
+static const char *handler[]= {
+ "prefetch abort",
+ "data abort",
+ "address exception",
+ "interrupt",
+ "undefined instruction",
+};
-#include "ptrace.h"
-#include "signal.h"
-
-static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
+void *vectors_page;
#ifdef CONFIG_DEBUG_USER
unsigned int user_debug;
@@ -53,7 +62,7 @@ static void dump_mem(const char *, const char *, unsigned long, unsigned long);
void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
{
#ifdef CONFIG_KALLSYMS
- printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
+ printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
#else
printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
#endif
@@ -137,7 +146,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
fs = get_fs();
set_fs(KERNEL_DS);
- for (i = -4; i < 1; i++) {
+ for (i = -4; i < 1 + !!thumb; i++) {
unsigned int val, bad;
if (thumb)
@@ -200,13 +209,6 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
}
#endif
-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
@@ -223,26 +225,30 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
#else
#define S_SMP ""
#endif
+#ifdef CONFIG_THUMB2_KERNEL
+#define S_ISA " THUMB2"
+#else
+#define S_ISA " ARM"
+#endif
-static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
+static int __die(const char *str, int err, struct pt_regs *regs)
{
- struct task_struct *tsk = thread->task;
+ struct task_struct *tsk = current;
static int die_counter;
int ret;
- printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
- str, err, ++die_counter);
- sysfs_printk_last_file();
+ printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP
+ S_ISA "\n", str, err, ++die_counter);
/* trap and error numbers are mostly meaningless on ARM */
ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
if (ret == NOTIFY_STOP)
- return ret;
+ return 1;
print_modules();
__show_regs(regs);
printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
- TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
+ TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk));
if (!user_mode(regs) || in_interrupt()) {
dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
@@ -251,40 +257,77 @@ static int __die(const char *str, int err, struct thread_info *thread, struct pt
dump_instr(KERN_EMERG, regs);
}
- return ret;
+ return 0;
}
-DEFINE_SPINLOCK(die_lock);
+static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
+static unsigned int die_nest_count;
-/*
- * This function is protected against re-entrancy.
- */
-void die(const char *str, struct pt_regs *regs, int err)
+static unsigned long oops_begin(void)
{
- struct thread_info *thread = current_thread_info();
- int ret;
+ int cpu;
+ unsigned long flags;
oops_enter();
- spin_lock_irq(&die_lock);
+ /* racy, but better than risking deadlock. */
+ raw_local_irq_save(flags);
+ cpu = smp_processor_id();
+ if (!arch_spin_trylock(&die_lock)) {
+ if (cpu == die_owner)
+ /* nested oops. should stop eventually */;
+ else
+ arch_spin_lock(&die_lock);
+ }
+ die_nest_count++;
+ die_owner = cpu;
console_verbose();
bust_spinlocks(1);
- ret = __die(str, err, thread, regs);
+ return flags;
+}
- if (regs && kexec_should_crash(thread->task))
+static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
+{
+ if (regs && kexec_should_crash(current))
crash_kexec(regs);
bust_spinlocks(0);
- add_taint(TAINT_DIE);
- spin_unlock_irq(&die_lock);
+ die_owner = -1;
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+ die_nest_count--;
+ if (!die_nest_count)
+ /* Nest count reaches zero, release the lock. */
+ arch_spin_unlock(&die_lock);
+ raw_local_irq_restore(flags);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
- if (ret != NOTIFY_STOP)
- do_exit(SIGSEGV);
+ if (signr)
+ do_exit(signr);
+}
+
+/*
+ * This function is protected against re-entrancy.
+ */
+void die(const char *str, struct pt_regs *regs, int err)
+{
+ enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
+ unsigned long flags = oops_begin();
+ int sig = SIGSEGV;
+
+ if (!user_mode(regs))
+ bug_type = report_bug(regs->ARM_pc, regs);
+ if (bug_type != BUG_TRAP_TYPE_NONE)
+ str = "Oops - BUG";
+
+ if (__die(str, err, regs))
+ sig = 0;
+
+ oops_end(flags, regs, sig);
}
void arm_notify_die(const char *str, struct pt_regs *regs,
@@ -300,25 +343,45 @@ void arm_notify_die(const char *str, struct pt_regs *regs,
}
}
+#ifdef CONFIG_GENERIC_BUG
+
+int is_valid_bugaddr(unsigned long pc)
+{
+#ifdef CONFIG_THUMB2_KERNEL
+ u16 bkpt;
+ u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
+#else
+ u32 bkpt;
+ u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
+#endif
+
+ if (probe_kernel_address((unsigned *)pc, bkpt))
+ return 0;
+
+ return bkpt == insn;
+}
+
+#endif
+
static LIST_HEAD(undef_hook);
-static DEFINE_SPINLOCK(undef_lock);
+static DEFINE_RAW_SPINLOCK(undef_lock);
void register_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
- spin_lock_irqsave(&undef_lock, flags);
+ raw_spin_lock_irqsave(&undef_lock, flags);
list_add(&hook->node, &undef_hook);
- spin_unlock_irqrestore(&undef_lock, flags);
+ raw_spin_unlock_irqrestore(&undef_lock, flags);
}
void unregister_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
- spin_lock_irqsave(&undef_lock, flags);
+ raw_spin_lock_irqsave(&undef_lock, flags);
list_del(&hook->node);
- spin_unlock_irqrestore(&undef_lock, flags);
+ raw_spin_unlock_irqrestore(&undef_lock, flags);
}
static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
@@ -327,47 +390,62 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
unsigned long flags;
int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
- spin_lock_irqsave(&undef_lock, flags);
+ raw_spin_lock_irqsave(&undef_lock, flags);
list_for_each_entry(hook, &undef_hook, node)
if ((instr & hook->instr_mask) == hook->instr_val &&
(regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
fn = hook->fn;
- spin_unlock_irqrestore(&undef_lock, flags);
+ raw_spin_unlock_irqrestore(&undef_lock, flags);
return fn ? fn(regs, instr) : 1;
}
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
- unsigned int correction = thumb_mode(regs) ? 2 : 4;
unsigned int instr;
siginfo_t info;
void __user *pc;
- /*
- * According to the ARM ARM, PC is 2 or 4 bytes ahead,
- * depending whether we're in Thumb mode or not.
- * Correct this offset.
- */
- regs->ARM_pc -= correction;
-
pc = (void __user *)instruction_pointer(regs);
if (processor_mode(regs) == SVC_MODE) {
- instr = *(u32 *) pc;
+#ifdef CONFIG_THUMB2_KERNEL
+ if (thumb_mode(regs)) {
+ instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
+ if (is_wide_instruction(instr)) {
+ u16 inst2;
+ inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
+ instr = __opcode_thumb32_compose(instr, inst2);
+ }
+ } else
+#endif
+ instr = __mem_to_opcode_arm(*(u32 *) pc);
} else if (thumb_mode(regs)) {
- get_user(instr, (u16 __user *)pc);
+ if (get_user(instr, (u16 __user *)pc))
+ goto die_sig;
+ instr = __mem_to_opcode_thumb16(instr);
+ if (is_wide_instruction(instr)) {
+ unsigned int instr2;
+ if (get_user(instr2, (u16 __user *)pc+1))
+ goto die_sig;
+ instr2 = __mem_to_opcode_thumb16(instr2);
+ instr = __opcode_thumb32_compose(instr, instr2);
+ }
} else {
- get_user(instr, (u32 __user *)pc);
+ if (get_user(instr, (u32 __user *)pc))
+ goto die_sig;
+ instr = __mem_to_opcode_arm(instr);
}
if (call_undef_hook(regs, instr) == 0)
return;
+die_sig:
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_UNDEFINED) {
printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
current->comm, task_pid_nr(current), pc);
+ __show_regs(regs);
dump_instr(KERN_INFO, regs);
}
#endif
@@ -408,8 +486,7 @@ static int bad_syscall(int n, struct pt_regs *regs)
struct thread_info *thread = current_thread_info();
siginfo_t info;
- if (current->personality != PER_LINUX &&
- current->personality != PER_LINUX_32BIT &&
+ if ((current->personality & PER_MASK) != PER_LINUX &&
thread->exec_domain->handler) {
thread->exec_domain->handler(n, regs);
return regs->ARM_r0;
@@ -434,26 +511,65 @@ static int bad_syscall(int n, struct pt_regs *regs)
return regs->ARM_r0;
}
-static inline void
-do_cache_op(unsigned long start, unsigned long end, int flags)
+static long do_cache_op_restart(struct restart_block *);
+
+static inline int
+__do_cache_op(unsigned long start, unsigned long end)
+{
+ int ret;
+
+ do {
+ unsigned long chunk = min(PAGE_SIZE, end - start);
+
+ if (signal_pending(current)) {
+ struct thread_info *ti = current_thread_info();
+
+ ti->restart_block = (struct restart_block) {
+ .fn = do_cache_op_restart,
+ };
+
+ ti->arm_restart_block = (struct arm_restart_block) {
+ {
+ .cache = {
+ .start = start,
+ .end = end,
+ },
+ },
+ };
+
+ return -ERESTART_RESTARTBLOCK;
+ }
+
+ ret = flush_cache_user_range(start, start + chunk);
+ if (ret)
+ return ret;
+
+ cond_resched();
+ start += chunk;
+ } while (start < end);
+
+ return 0;
+}
+
+static long do_cache_op_restart(struct restart_block *unused)
{
- struct mm_struct *mm = current->active_mm;
- struct vm_area_struct *vma;
+ struct arm_restart_block *restart_block;
+
+ restart_block = &current_thread_info()->arm_restart_block;
+ return __do_cache_op(restart_block->cache.start,
+ restart_block->cache.end);
+}
+static inline int
+do_cache_op(unsigned long start, unsigned long end, int flags)
+{
if (end < start || flags)
- return;
+ return -EINVAL;
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, start);
- if (vma && vma->vm_start < end) {
- if (start < vma->vm_start)
- start = vma->vm_start;
- if (end > vma->vm_end)
- end = vma->vm_end;
+ if (!access_ok(VERIFY_READ, start, end - start))
+ return -EFAULT;
- flush_cache_user_range(vma, start, end);
- }
- up_read(&mm->mmap_sem);
+ return __do_cache_op(start, end);
}
/*
@@ -499,8 +615,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
* the specified region).
*/
case NR(cacheflush):
- do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
- return 0;
+ return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
case NR(usr26):
if (!(elf_hwcap & HWCAP_26BIT))
@@ -515,7 +630,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
return regs->ARM_r0;
case NR(set_tls):
- thread->tp_value = regs->ARM_r0;
+ thread->tp_value[0] = regs->ARM_r0;
if (tls_emu)
return 0;
if (has_tls_reg) {
@@ -563,7 +678,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
if (!pmd_present(*pmd))
goto bad_access;
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
- if (!pte_present(*pte) || !pte_dirty(*pte)) {
+ if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) {
pte_unmap_unlock(pte, ptl);
goto bad_access;
}
@@ -633,7 +748,7 @@ static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
int reg = (instr >> 12) & 15;
if (reg == 15)
return 1;
- regs->uregs[reg] = current_thread_info()->tp_value;
+ regs->uregs[reg] = current_thread_info()->tp_value[0];
regs->ARM_pc += 4;
return 0;
}
@@ -691,16 +806,6 @@ baddataabort(int code, unsigned long instr, struct pt_regs *regs)
arm_notify_die("unknown data abort code", regs, &info, instr, 0);
}
-void __attribute__((noreturn)) __bug(const char *file, int line)
-{
- printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line);
- *(int *)0 = 0;
-
- /* Avoid "noreturn function does return" */
- for (;;);
-}
-EXPORT_SYMBOL(__bug);
-
void __readwrite_bug(const char *fn)
{
printk("%s called, but not implemented\n", fn);
@@ -708,19 +813,19 @@ void __readwrite_bug(const char *fn)
}
EXPORT_SYMBOL(__readwrite_bug);
-void __pte_error(const char *file, int line, unsigned long val)
+void __pte_error(const char *file, int line, pte_t pte)
{
- printk("%s:%d: bad pte %08lx.\n", file, line, val);
+ printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
}
-void __pmd_error(const char *file, int line, unsigned long val)
+void __pmd_error(const char *file, int line, pmd_t pmd)
{
- printk("%s:%d: bad pmd %08lx.\n", file, line, val);
+ printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
}
-void __pgd_error(const char *file, int line, unsigned long val)
+void __pgd_error(const char *file, int line, pgd_t pgd)
{
- printk("%s:%d: bad pgd %08lx.\n", file, line, val);
+ printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
}
asmlinkage void __div0(void)
@@ -744,23 +849,45 @@ void __init trap_init(void)
return;
}
-static void __init kuser_get_tls_init(unsigned long vectors)
+#ifdef CONFIG_KUSER_HELPERS
+static void __init kuser_init(void *vectors)
{
+ extern char __kuser_helper_start[], __kuser_helper_end[];
+ int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+
+ memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
+
/*
* vectors + 0xfe0 = __kuser_get_tls
* vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
*/
if (tls_emu || has_tls_reg)
- memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4);
+ memcpy(vectors + 0xfe0, vectors + 0xfe8, 4);
+}
+#else
+static inline void __init kuser_init(void *vectors)
+{
}
+#endif
-void __init early_trap_init(void)
+void __init early_trap_init(void *vectors_base)
{
- unsigned long vectors = CONFIG_VECTORS_BASE;
+#ifndef CONFIG_CPU_V7M
+ unsigned long vectors = (unsigned long)vectors_base;
extern char __stubs_start[], __stubs_end[];
extern char __vectors_start[], __vectors_end[];
- extern char __kuser_helper_start[], __kuser_helper_end[];
- int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+ unsigned i;
+
+ vectors_page = vectors_base;
+
+ /*
+ * Poison the vectors page with an undefined instruction. This
+ * instruction is chosen to be undefined for both ARM and Thumb
+ * ISAs. The Thumb version is an undefined instruction with a
+ * branch back to the undefined instruction.
+ */
+ for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
+ ((u32 *)vectors_base)[i] = 0xe7fddef1;
/*
* Copy the vectors, stubs and kuser helpers (in entry-armv.S)
@@ -768,23 +895,17 @@ void __init early_trap_init(void)
* are visible to the instruction stream.
*/
memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
- memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start);
- memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
+ memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
- /*
- * Do processor specific fixups for the kuser helpers
- */
- kuser_get_tls_init(vectors);
+ kuser_init(vectors_base);
+ flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
+ modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
+#else /* ifndef CONFIG_CPU_V7M */
/*
- * Copy signal return handlers into the vector page, and
- * set sigreturn to be a pointer to these.
+ * on V7-M there is no need to copy the vector table to a dedicated
+ * memory area. The address is configurable and so a table in the kernel
+ * image can be used.
*/
- memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes,
- sizeof(sigreturn_codes));
- memcpy((void *)KERN_RESTART_CODE, syscall_restart_code,
- sizeof(syscall_restart_code));
-
- flush_icache_range(vectors, vectors + PAGE_SIZE);
- modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
+#endif
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-05 11:39:18 +0000