select MODULES_USE_ELF_RELA
select HAVE_ARCH_TRACEHOOK
select HAVE_SYSCALL_TRACEPOINTS
+ select USER_STACKTRACE_SUPPORT
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select HAVE_DEBUG_STACKOVERFLOW
select ARCH_WANT_FRAME_POINTERS
select HAVE_CONTEXT_TRACKING
select EDAC_SUPPORT
+ select GENERIC_STRNCPY_FROM_USER
+ select GENERIC_STRNLEN_USER
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
select HVC_IRQ if TILEGX
def_bool y
+# Building with ARCH=tilegx (or ARCH=tile) implies using the
+# 64-bit TILE-Gx toolchain, so force CONFIG_TILEGX on.
config TILEGX
- bool "Building for TILE-Gx (64-bit) processor"
+ def_bool ARCH != "tilepro"
select SPARSE_IRQ
select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
select HAVE_FUNCTION_TRACER
void setup_irq_regs(void);
+#ifdef __tilegx__
+void arch_trigger_all_cpu_backtrace(bool self);
+#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace
+#endif
+
#endif /* _ASM_TILE_IRQ_H */
unsigned long long interrupt_mask;
/* User interrupt-control 0 state */
unsigned long intctrl_0;
- /* Is this task currently doing a backtrace? */
- bool in_backtrace;
/* Any other miscellaneous processor state bits */
unsigned long proc_status;
#if !CHIP_HAS_FIXED_INTVEC_BASE()
* to claim the lock is held, since it will be momentarily
* if not already. There's no need to wait for a "valid"
* lock->next_ticket to become available.
+ * Use READ_ONCE() to ensure that calling this in a loop is OK.
*/
- return lock->next_ticket != lock->current_ticket;
+ int curr = READ_ONCE(lock->current_ticket);
+ int next = READ_ONCE(lock->next_ticket);
+
+ return next != curr;
}
void arch_spin_lock(arch_spinlock_t *lock);
#ifndef _ASM_TILE_SPINLOCK_64_H
#define _ASM_TILE_SPINLOCK_64_H
+#include <linux/compiler.h>
+
/* Shifts and masks for the various fields in "lock". */
#define __ARCH_SPIN_CURRENT_SHIFT 17
#define __ARCH_SPIN_NEXT_MASK 0x7fff
/* The lock is locked if a task would have to wait to get it. */
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
- u32 val = lock->lock;
+ /* Use READ_ONCE() to ensure that calling this in a loop is OK. */
+ u32 val = READ_ONCE(lock->lock);
return arch_spin_current(val) != arch_spin_next(val);
}
/* Advance to the next frame. */
extern void KBacktraceIterator_next(struct KBacktraceIterator *kbt);
+/* Dump just the contents of the pt_regs structure. */
+extern void tile_show_regs(struct pt_regs *);
+
/*
* Dump stack given complete register info. Use only from the
* architecture-specific code; show_stack()
- * and dump_stack() (in entry.S) are architecture-independent entry points.
+ * and dump_stack() are architecture-independent entry points.
*/
-extern void tile_show_stack(struct KBacktraceIterator *, int headers);
-
-/* Dump stack of current process, with registers to seed the backtrace. */
-extern void dump_stack_regs(struct pt_regs *);
-
-/* Helper method for assembly dump_stack(). */
-extern void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52);
+extern void tile_show_stack(struct KBacktraceIterator *);
#endif /* _ASM_TILE_STACK_H */
unsigned long unalign_jit_tmp[4]; /* temp r0..r3 storage */
void __user *unalign_jit_base; /* unalign fixup JIT base */
#endif
+ bool in_backtrace; /* currently doing backtrace? */
};
/*
/* kernel/messaging.c */
void hv_message_intr(struct pt_regs *, int intnum);
+#define TILE_NMI_DUMP_STACK 1 /* Dump stack for sysrq+'l' */
+
+/* kernel/process.c */
+void do_nmi_dump_stack(struct pt_regs *regs);
+
+/* kernel/traps.c */
+void do_nmi(struct pt_regs *, int fault_num, unsigned long reason);
+
/* kernel/irq.c */
void tile_dev_intr(struct pt_regs *, int intnum);
#endif
/*
+ * Note that using this definition ignores is_arch_mappable_range(),
+ * so on tilepro code that uses user_addr_max() is constrained not
+ * to reference the tilepro user-interrupt region.
+ */
+#define user_addr_max() (current_thread_info()->addr_limit.seg)
+
+/*
* Test whether a block of memory is a valid user space address.
* Returns 0 if the range is valid, nonzero otherwise.
*/
#endif
-/**
- * strlen_user: - Get the size of a string in user space.
- * @str: The string to measure.
- *
- * Context: User context only. This function may sleep.
- *
- * Get the size of a NUL-terminated string in user space.
- *
- * Returns the size of the string INCLUDING the terminating NUL.
- * On exception, returns 0.
- *
- * If there is a limit on the length of a valid string, you may wish to
- * consider using strnlen_user() instead.
- */
-extern long strnlen_user_asm(const char __user *str, long n);
-static inline long __must_check strnlen_user(const char __user *str, long n)
-{
- might_fault();
- return strnlen_user_asm(str, n);
-}
-#define strlen_user(str) strnlen_user(str, LONG_MAX)
-
-/**
- * strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
- * @dst: Destination address, in kernel space. This buffer must be at
- * least @count bytes long.
- * @src: Source address, in user space.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from userspace to kernel space.
- * Caller must check the specified block with access_ok() before calling
- * this function.
- *
- * On success, returns the length of the string (not including the trailing
- * NUL).
- *
- * If access to userspace fails, returns -EFAULT (some data may have been
- * copied).
- *
- * If @count is smaller than the length of the string, copies @count bytes
- * and returns @count.
- */
-extern long strncpy_from_user_asm(char *dst, const char __user *src, long);
-static inline long __must_check __strncpy_from_user(
- char *dst, const char __user *src, long count)
-{
- might_fault();
- return strncpy_from_user_asm(dst, src, count);
-}
-static inline long __must_check strncpy_from_user(
- char *dst, const char __user *src, long count)
-{
- if (access_ok(VERIFY_READ, src, 1))
- return __strncpy_from_user(dst, src, count);
- return -EFAULT;
-}
+extern long strnlen_user(const char __user *str, long n);
+extern long strlen_user(const char __user *str);
+extern long strncpy_from_user(char *dst, const char __user *src, long);
/**
* clear_user: - Zero a block of memory in user space.
--- /dev/null
+#ifndef _ASM_WORD_AT_A_TIME_H
+#define _ASM_WORD_AT_A_TIME_H
+
+#include <asm/byteorder.h>
+
+struct word_at_a_time { /* unused */ };
+#define WORD_AT_A_TIME_CONSTANTS {}
+
+/* Generate 0x01 byte values for non-zero bytes using a SIMD instruction. */
+static inline unsigned long has_zero(unsigned long val, unsigned long *data,
+ const struct word_at_a_time *c)
+{
+#ifdef __tilegx__
+ unsigned long mask = __insn_v1cmpeqi(val, 0);
+#else /* tilepro */
+ unsigned long mask = __insn_seqib(val, 0);
+#endif
+ *data = mask;
+ return mask;
+}
+
+/* These operations are both nops. */
+#define prep_zero_mask(val, data, c) (data)
+#define create_zero_mask(data) (data)
+
+/* And this operation just depends on endianness. */
+static inline long find_zero(unsigned long mask)
+{
+#ifdef __BIG_ENDIAN
+ return __builtin_clzl(mask) >> 3;
+#else
+ return __builtin_ctzl(mask) >> 3;
+#endif
+}
+
+#endif /* _ASM_WORD_AT_A_TIME_H */
/** hv_console_set_ipi */
#define HV_DISPATCH_CONSOLE_SET_IPI 63
+/** hv_send_nmi */
+#define HV_DISPATCH_SEND_NMI 65
+
/** One more than the largest dispatch value */
-#define _HV_DISPATCH_END 64
+#define _HV_DISPATCH_END 66
#ifndef __ASSEMBLER__
#define INT_DMATLB_ACCESS_DWNCL INT_DMA_CPL
/** Device interrupt downcall interrupt vector */
#define INT_DEV_INTR_DWNCL INT_WORLD_ACCESS
+/** NMI downcall interrupt vector */
+#define INT_NMI_DWNCL 64
+
+#define HV_NMI_FLAG_FORCE 0x1 /**< Force an NMI downcall regardless of
+ the ICS bit of the client. */
#ifndef __ASSEMBLER__
int hv_dev_poll_cancel(int devhdl);
+/** NMI information */
+typedef struct
+{
+ /** Result: negative error, or HV_NMI_RESULT_xxx. */
+ int result;
+
+ /** PC from interrupted remote core (if result != HV_NMI_RESULT_FAIL_HV). */
+ HV_VirtAddr pc;
+
+} HV_NMI_Info;
+
+/** NMI issued successfully. */
+#define HV_NMI_RESULT_OK 0
+
+/** NMI not issued: remote tile running at client PL with ICS set. */
+#define HV_NMI_RESULT_FAIL_ICS 1
+
+/** NMI not issued: remote tile waiting in hypervisor. */
+#define HV_NMI_RESULT_FAIL_HV 2
+
+/** Force an NMI downcall regardless of the ICS bit of the client. */
+#define HV_NMI_FLAG_FORCE 0x1
+
+/** Send an NMI interrupt request to a particular tile.
+ *
+ * This will cause the NMI to be issued on the remote tile regardless
+ * of the state of the client interrupt mask. However, if the remote
+ * tile is in the hypervisor, it will not execute the NMI, and
+ * HV_NMI_RESULT_FAIL_HV will be returned. Similarly, if the remote
+ * tile is in a client interrupt critical section at the time of the
+ * NMI, it will not execute the NMI, and HV_NMI_RESULT_FAIL_ICS will
+ * be returned. In this second case, however, if HV_NMI_FLAG_FORCE
+ * is set in flags, then the remote tile will enter its NMI interrupt
+ * vector regardless. Forcing the NMI vector during an interrupt
+ * critical section will mean that the client can not safely continue
+ * execution after handling the interrupt.
+ *
+ * @param tile Tile to which the NMI request is sent.
+ * @param info NMI information which is defined by and interpreted by the
+ * supervisor, is passed to the specified tile, and is
+ * stored in the SPR register SYSTEM_SAVE_{CLIENT_PL}_2 on the
+ * specified tile when entering the NMI handler routine.
+ * Typically, this parameter stores the NMI type, or an aligned
+ * VA plus some special bits, etc.
+ * @param flags Flags (HV_NMI_FLAG_xxx).
+ * @return Information about the requested NMI.
+ */
+HV_NMI_Info hv_send_nmi(HV_Coord tile, unsigned long info, __hv64 flags);
+
+
/** Scatter-gather list for preada/pwritea calls. */
typedef struct
#if CHIP_VA_WIDTH() <= 32
{ move r0, lr; jrp lr }
STD_ENDPROC(current_text_addr)
-STD_ENTRY(dump_stack)
- { move r2, lr; lnk r1 }
- { move r4, r52; addli r1, r1, dump_stack - . }
- { move r3, sp; j _dump_stack }
- jrp lr /* keep backtracer happy */
- STD_ENDPROC(dump_stack)
-
STD_ENTRY(KBacktraceIterator_init_current)
{ move r2, lr; lnk r1 }
{ move r4, r52; addli r1, r1, KBacktraceIterator_init_current - . }
gensym hv_get_ipi_pte, 0x700, 32
gensym hv_set_pte_super_shift, 0x720, 32
gensym hv_console_set_ipi, 0x7e0, 32
-gensym hv_glue_internals, 0x800, 30720
+gensym hv_send_nmi, 0x820, 32
+gensym hv_glue_internals, 0x820, 30688
#define hv_get_ipi_pte _hv_get_ipi_pte
#define hv_set_pte_super_shift _hv_set_pte_super_shift
#define hv_console_set_ipi _hv_console_set_ipi
+#define hv_send_nmi _hv_send_nmi
#include <hv/hypervisor.h>
#undef hv_init
#undef hv_install_context
#undef hv_get_ipi_pte
#undef hv_set_pte_super_shift
#undef hv_console_set_ipi
+#undef hv_send_nmi
/*
* Provide macros based on <linux/syscalls.h> to provide a wrapper
HV_VirtAddr, tlb_va, unsigned long, tlb_length,
unsigned long, tlb_pgsize, unsigned long*, tlb_cpumask,
HV_Remote_ASID*, asids, int, asidcount)
+HV_WRAP3(HV_NMI_Info, hv_send_nmi, HV_Coord, tile, unsigned long, info,
+ __hv64, flags)
.ifc \c_routine, handle_perf_interrupt
mfspr r2, AUX_PERF_COUNT_STS
.endif
+ .ifc \c_routine, do_nmi
+ mfspr r2, SPR_SYSTEM_SAVE_K_2 /* nmi type */
+ .else
+ .endif
.endif
.endif
.endif
/* Synthetic interrupt delivered only by the simulator */
int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint
+ /* Synthetic interrupt delivered by hv */
+ int_hand INT_NMI_DWNCL, NMI_DWNCL, do_nmi, handle_nmi
#include <linux/kernel.h>
#include <linux/tracehook.h>
#include <linux/signal.h>
+#include <linux/delay.h>
#include <linux/context_tracking.h>
#include <asm/stack.h>
#include <asm/switch_to.h>
(CALLEE_SAVED_REGS_COUNT - 2) * sizeof(unsigned long));
callee_regs[0] = sp; /* r30 = function */
callee_regs[1] = arg; /* r31 = arg */
- childregs->ex1 = PL_ICS_EX1(KERNEL_PL, 0);
p->thread.pc = (unsigned long) ret_from_kernel_thread;
return 0;
}
#endif
}
-void show_regs(struct pt_regs *regs)
+void tile_show_regs(struct pt_regs *regs)
{
- struct task_struct *tsk = validate_current();
int i;
-
- if (tsk != &corrupt_current)
- show_regs_print_info(KERN_ERR);
#ifdef __tilegx__
for (i = 0; i < 17; i++)
- pr_err(" r%-2d: " REGFMT " r%-2d: " REGFMT " r%-2d: " REGFMT "\n",
+ pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
i, regs->regs[i], i+18, regs->regs[i+18],
i+36, regs->regs[i+36]);
- pr_err(" r17: " REGFMT " r35: " REGFMT " tp : " REGFMT "\n",
+ pr_err(" r17: "REGFMT" r35: "REGFMT" tp : "REGFMT"\n",
regs->regs[17], regs->regs[35], regs->tp);
- pr_err(" sp : " REGFMT " lr : " REGFMT "\n", regs->sp, regs->lr);
+ pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr);
#else
for (i = 0; i < 13; i++)
- pr_err(" r%-2d: " REGFMT " r%-2d: " REGFMT " r%-2d: " REGFMT " r%-2d: " REGFMT "\n",
+ pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT
+ " r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
i, regs->regs[i], i+14, regs->regs[i+14],
i+27, regs->regs[i+27], i+40, regs->regs[i+40]);
- pr_err(" r13: " REGFMT " tp : " REGFMT " sp : " REGFMT " lr : " REGFMT "\n",
+ pr_err(" r13: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n",
regs->regs[13], regs->tp, regs->sp, regs->lr);
#endif
- pr_err(" pc : " REGFMT " ex1: %ld faultnum: %ld\n",
- regs->pc, regs->ex1, regs->faultnum);
+ pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld flags:%s%s%s%s\n",
+ regs->pc, regs->ex1, regs->faultnum,
+ is_compat_task() ? " compat" : "",
+ (regs->flags & PT_FLAGS_DISABLE_IRQ) ? " noirq" : "",
+ !(regs->flags & PT_FLAGS_CALLER_SAVES) ? " nocallersave" : "",
+ (regs->flags & PT_FLAGS_RESTORE_REGS) ? " restoreregs" : "");
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ struct KBacktraceIterator kbt;
+
+ show_regs_print_info(KERN_DEFAULT);
+ tile_show_regs(regs);
+
+ KBacktraceIterator_init(&kbt, NULL, regs);
+ tile_show_stack(&kbt);
+}
+
+/* To ensure stack dump on tiles occurs one by one. */
+static DEFINE_SPINLOCK(backtrace_lock);
+/* To ensure no backtrace occurs before all of the stack dump are done. */
+static atomic_t backtrace_cpus;
+/* The cpu mask to avoid reentrance. */
+static struct cpumask backtrace_mask;
- dump_stack_regs(regs);
+void do_nmi_dump_stack(struct pt_regs *regs)
+{
+ int is_idle = is_idle_task(current) && !in_interrupt();
+ int cpu;
+
+ nmi_enter();
+ cpu = smp_processor_id();
+ if (WARN_ON_ONCE(!cpumask_test_and_clear_cpu(cpu, &backtrace_mask)))
+ goto done;
+
+ spin_lock(&backtrace_lock);
+ if (is_idle)
+ pr_info("CPU: %d idle\n", cpu);
+ else
+ show_regs(regs);
+ spin_unlock(&backtrace_lock);
+ atomic_dec(&backtrace_cpus);
+done:
+ nmi_exit();
+}
+
+#ifdef __tilegx__
+void arch_trigger_all_cpu_backtrace(bool self)
+{
+ struct cpumask mask;
+ HV_Coord tile;
+ unsigned int timeout;
+ int cpu;
+ int ongoing;
+ HV_NMI_Info info[NR_CPUS];
+
+ ongoing = atomic_cmpxchg(&backtrace_cpus, 0, num_online_cpus() - 1);
+ if (ongoing != 0) {
+ pr_err("Trying to do all-cpu backtrace.\n");
+ pr_err("But another all-cpu backtrace is ongoing (%d cpus left)\n",
+ ongoing);
+ if (self) {
+ pr_err("Reporting the stack on this cpu only.\n");
+ dump_stack();
+ }
+ return;
+ }
+
+ cpumask_copy(&mask, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), &mask);
+ cpumask_copy(&backtrace_mask, &mask);
+
+ /* Backtrace for myself first. */
+ if (self)
+ dump_stack();
+
+ /* Tentatively dump stack on remote tiles via NMI. */
+ timeout = 100;
+ while (!cpumask_empty(&mask) && timeout) {
+ for_each_cpu(cpu, &mask) {
+ tile.x = cpu_x(cpu);
+ tile.y = cpu_y(cpu);
+ info[cpu] = hv_send_nmi(tile, TILE_NMI_DUMP_STACK, 0);
+ if (info[cpu].result == HV_NMI_RESULT_OK)
+ cpumask_clear_cpu(cpu, &mask);
+ }
+
+ mdelay(10);
+ timeout--;
+ }
+
+ /* Warn about cpus stuck in ICS and decrement their counts here. */
+ if (!cpumask_empty(&mask)) {
+ for_each_cpu(cpu, &mask) {
+ switch (info[cpu].result) {
+ case HV_NMI_RESULT_FAIL_ICS:
+ pr_warn("Skipping stack dump of cpu %d in ICS at pc %#llx\n",
+ cpu, info[cpu].pc);
+ break;
+ case HV_NMI_RESULT_FAIL_HV:
+ pr_warn("Skipping stack dump of cpu %d in hypervisor\n",
+ cpu);
+ break;
+ case HV_ENOSYS:
+ pr_warn("Hypervisor too old to allow remote stack dumps.\n");
+ goto skip_for_each;
+ default: /* should not happen */
+ pr_warn("Skipping stack dump of cpu %d [%d,%#llx]\n",
+ cpu, info[cpu].result, info[cpu].pc);
+ break;
+ }
+ }
+skip_for_each:
+ atomic_sub(cpumask_weight(&mask), &backtrace_cpus);
+ }
}
+#endif /* __tilegx_ */
* per-CPU stack and boot info.
*/
DEFINE_PER_CPU(unsigned long, boot_sp) =
- (unsigned long)init_stack + THREAD_SIZE;
+ (unsigned long)init_stack + THREAD_SIZE - STACK_TOP_DELTA;
#ifdef CONFIG_SMP
DEFINE_PER_CPU(unsigned long, boot_pc) = (unsigned long)start_kernel;
#include <linux/mmzone.h>
#include <linux/dcache.h>
#include <linux/fs.h>
+#include <linux/hardirq.h>
#include <linux/string.h>
#include <asm/backtrace.h>
#include <asm/page.h>
if (kbt->verbose)
pr_err(" <%s while in user mode>\n", fault);
} else {
- if (kbt->verbose)
+ if (kbt->verbose && (p->pc != 0 || p->sp != 0 || p->ex1 != 0))
pr_err(" (odd fault: pc %#lx, sp %#lx, ex1 %#lx?)\n",
p->pc, p->sp, p->ex1);
return NULL;
return p;
}
-/* Is the pc pointing to a sigreturn trampoline? */
-static int is_sigreturn(unsigned long pc)
+/* Is the iterator pointing to a sigreturn trampoline? */
+static int is_sigreturn(struct KBacktraceIterator *kbt)
{
- return current->mm && (pc == VDSO_SYM(&__vdso_rt_sigreturn));
+ return kbt->task->mm &&
+ (kbt->it.pc == ((ulong)kbt->task->mm->context.vdso_base +
+ (ulong)&__vdso_rt_sigreturn));
}
/* Return a pt_regs pointer for a valid signal handler frame */
{
BacktraceIterator *b = &kbt->it;
- if (is_sigreturn(b->pc) && b->sp < PAGE_OFFSET &&
+ if (is_sigreturn(kbt) && b->sp < PAGE_OFFSET &&
b->sp % sizeof(long) == 0) {
int retval;
pagefault_disable();
return NULL;
}
-static int KBacktraceIterator_is_sigreturn(struct KBacktraceIterator *kbt)
-{
- return is_sigreturn(kbt->it.pc);
-}
-
static int KBacktraceIterator_restart(struct KBacktraceIterator *kbt)
{
struct pt_regs *p;
{
for (;;) {
do {
- if (!KBacktraceIterator_is_sigreturn(kbt))
+ if (!is_sigreturn(kbt))
return KBT_ONGOING;
} while (backtrace_next(&kbt->it));
*/
static bool start_backtrace(void)
{
- if (current->thread.in_backtrace) {
+ if (current_thread_info()->in_backtrace) {
pr_err("Backtrace requested while in backtrace!\n");
return false;
}
- current->thread.in_backtrace = true;
+ current_thread_info()->in_backtrace = true;
return true;
}
static void end_backtrace(void)
{
- current->thread.in_backtrace = false;
+ current_thread_info()->in_backtrace = false;
}
/*
* This method wraps the backtracer's more generic support.
* It is only invoked from the architecture-specific code; show_stack()
- * and dump_stack() (in entry.S) are architecture-independent entry points.
+ * and dump_stack() are architecture-independent entry points.
*/
-void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
+void tile_show_stack(struct KBacktraceIterator *kbt)
{
int i;
int have_mmap_sem = 0;
if (!start_backtrace())
return;
- if (headers) {
- /*
- * Add a blank line since if we are called from panic(),
- * then bust_spinlocks() spit out a space in front of us
- * and it will mess up our KERN_ERR.
- */
- pr_err("Starting stack dump of tid %d, pid %d (%s) on cpu %d at cycle %lld\n",
- kbt->task->pid, kbt->task->tgid, kbt->task->comm,
- raw_smp_processor_id(), get_cycles());
- }
kbt->verbose = 1;
i = 0;
for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) {
char namebuf[KSYM_NAME_LEN+100];
unsigned long address = kbt->it.pc;
- /* Try to acquire the mmap_sem as we pass into userspace. */
- if (address < PAGE_OFFSET && !have_mmap_sem && kbt->task->mm)
+ /*
+ * Try to acquire the mmap_sem as we pass into userspace.
+ * If we're in an interrupt context, don't even try, since
+ * it's not safe to call e.g. d_path() from an interrupt,
+ * since it uses spin locks without disabling interrupts.
+ * Note we test "kbt->task == current", not "kbt->is_current",
+ * since we're checking that "current" will work in d_path().
+ */
+ if (kbt->task == current && address < PAGE_OFFSET &&
+ !have_mmap_sem && kbt->task->mm && !in_interrupt()) {
have_mmap_sem =
down_read_trylock(&kbt->task->mm->mmap_sem);
+ }
describe_addr(kbt, address, have_mmap_sem,
namebuf, sizeof(namebuf));
}
if (kbt->end == KBT_LOOP)
pr_err("Stack dump stopped; next frame identical to this one\n");
- if (headers)
- pr_err("Stack dump complete\n");
if (have_mmap_sem)
up_read(&kbt->task->mm->mmap_sem);
end_backtrace();
}
EXPORT_SYMBOL(tile_show_stack);
-
-/* This is called from show_regs() and _dump_stack() */
-void dump_stack_regs(struct pt_regs *regs)
-{
- struct KBacktraceIterator kbt;
- KBacktraceIterator_init(&kbt, NULL, regs);
- tile_show_stack(&kbt, 1);
-}
-EXPORT_SYMBOL(dump_stack_regs);
-
static struct pt_regs *regs_to_pt_regs(struct pt_regs *regs,
ulong pc, ulong lr, ulong sp, ulong r52)
{
return regs;
}
-/* This is called from dump_stack() and just converts to pt_regs */
+/* Deprecated function currently only used by kernel_double_fault(). */
void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52)
{
+ struct KBacktraceIterator kbt;
struct pt_regs regs;
- dump_stack_regs(regs_to_pt_regs(®s, pc, lr, sp, r52));
+
+ regs_to_pt_regs(®s, pc, lr, sp, r52);
+ KBacktraceIterator_init(&kbt, NULL, ®s);
+ tile_show_stack(&kbt);
}
/* This is called from KBacktraceIterator_init_current() */
regs_to_pt_regs(®s, pc, lr, sp, r52));
}
-/* This is called only from kernel/sched/core.c, with esp == NULL */
+/*
+ * Called from sched_show_task() with task != NULL, or dump_stack()
+ * with task == NULL. The esp argument is always NULL.
+ */
void show_stack(struct task_struct *task, unsigned long *esp)
{
struct KBacktraceIterator kbt;
- if (task == NULL || task == current)
+ if (task == NULL || task == current) {
KBacktraceIterator_init_current(&kbt);
- else
+ KBacktraceIterator_next(&kbt); /* don't show first frame */
+ } else {
KBacktraceIterator_init(&kbt, task, NULL);
- tile_show_stack(&kbt, 0);
+ }
+ tile_show_stack(&kbt);
}
#ifdef CONFIG_STACKTRACE
/* Support generic Linux stack API too */
-void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
+static void save_stack_trace_common(struct task_struct *task,
+ struct pt_regs *regs,
+ bool user,
+ struct stack_trace *trace)
{
struct KBacktraceIterator kbt;
int skip = trace->skip;
if (!start_backtrace())
goto done;
- if (task == NULL || task == current)
+ if (regs != NULL) {
+ KBacktraceIterator_init(&kbt, NULL, regs);
+ } else if (task == NULL || task == current) {
KBacktraceIterator_init_current(&kbt);
- else
+ skip++; /* don't show KBacktraceIterator_init_current */
+ } else {
KBacktraceIterator_init(&kbt, task, NULL);
+ }
for (; !KBacktraceIterator_end(&kbt); KBacktraceIterator_next(&kbt)) {
if (skip) {
--skip;
continue;
}
- if (i >= trace->max_entries || kbt.it.pc < PAGE_OFFSET)
+ if (i >= trace->max_entries ||
+ (!user && kbt.it.pc < PAGE_OFFSET))
break;
trace->entries[i++] = kbt.it.pc;
}
end_backtrace();
done:
+ if (i < trace->max_entries)
+ trace->entries[i++] = ULONG_MAX;
trace->nr_entries = i;
}
+
+void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
+{
+ save_stack_trace_common(task, NULL, false, trace);
+}
EXPORT_SYMBOL(save_stack_trace_tsk);
void save_stack_trace(struct stack_trace *trace)
{
- save_stack_trace_tsk(NULL, trace);
+ save_stack_trace_common(NULL, NULL, false, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
+void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+ save_stack_trace_common(NULL, regs, false, trace);
+}
+
+void save_stack_trace_user(struct stack_trace *trace)
+{
+ /* Trace user stack if we are not a kernel thread. */
+ if (current->mm)
+ save_stack_trace_common(NULL, task_pt_regs(current),
+ true, trace);
+ else if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
#endif
/* In entry.S */
exception_exit(prev_state);
}
+void do_nmi(struct pt_regs *regs, int fault_num, unsigned long reason)
+{
+ switch (reason) {
+ case TILE_NMI_DUMP_STACK:
+ do_nmi_dump_stack(regs);
+ break;
+ default:
+ panic("Unexpected do_nmi type %ld", reason);
+ return;
+ }
+}
+
+/* Deprecated function currently only used here. */
+extern void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52);
+
void kernel_double_fault(int dummy, ulong pc, ulong lr, ulong sp, ulong r52)
{
_dump_stack(dummy, pc, lr, sp, r52);
u64 ns;
do {
- count = read_seqcount_begin(&vdso->tb_seq);
+ count = raw_read_seqcount_begin(&vdso->tb_seq);
ts->tv_sec = vdso->wall_time_sec;
ns = vdso->wall_time_snsec;
ns += vgetsns(vdso);
u64 ns;
do {
- count = read_seqcount_begin(&vdso->tb_seq);
+ count = raw_read_seqcount_begin(&vdso->tb_seq);
ts->tv_sec = vdso->monotonic_time_sec;
ns = vdso->monotonic_time_snsec;
ns += vgetsns(vdso);
unsigned count;
do {
- count = read_seqcount_begin(&vdso->tb_seq);
+ count = raw_read_seqcount_begin(&vdso->tb_seq);
ts->tv_sec = vdso->wall_time_coarse_sec;
ts->tv_nsec = vdso->wall_time_coarse_nsec;
} while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
unsigned count;
do {
- count = read_seqcount_begin(&vdso->tb_seq);
+ count = raw_read_seqcount_begin(&vdso->tb_seq);
ts->tv_sec = vdso->monotonic_time_coarse_sec;
ts->tv_nsec = vdso->monotonic_time_coarse_nsec;
} while (unlikely(read_seqcount_retry(&vdso->tb_seq, count)));
/* The use of the timezone is obsolete, normally tz is NULL. */
if (unlikely(tz != NULL)) {
do {
- count = read_seqcount_begin(&vdso->tz_seq);
+ count = raw_read_seqcount_begin(&vdso->tz_seq);
tz->tz_minuteswest = vdso->tz_minuteswest;
tz->tz_dsttime = vdso->tz_dsttime;
} while (unlikely(read_seqcount_retry(&vdso->tz_seq, count)));
/* arch/tile/lib/usercopy.S */
#include <linux/uaccess.h>
-EXPORT_SYMBOL(strnlen_user_asm);
-EXPORT_SYMBOL(strncpy_from_user_asm);
EXPORT_SYMBOL(clear_user_asm);
EXPORT_SYMBOL(flush_user_asm);
EXPORT_SYMBOL(finv_user_asm);
#include <linux/kernel.h>
#include <asm/processor.h>
EXPORT_SYMBOL(current_text_addr);
-EXPORT_SYMBOL(dump_stack);
/* arch/tile/kernel/head.S */
EXPORT_SYMBOL(empty_zero_page);
void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
u32 iterations = 0;
- while (arch_spin_is_locked(lock))
+ int curr = READ_ONCE(lock->current_ticket);
+ int next = READ_ONCE(lock->next_ticket);
+
+ /* Return immediately if unlocked. */
+ if (next == curr)
+ return;
+
+ /* Wait until the current locker has released the lock. */
+ do {
delay_backoff(iterations++);
+ } while (READ_ONCE(lock->current_ticket) == curr);
}
EXPORT_SYMBOL(arch_spin_unlock_wait);
void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
u32 iterations = 0;
- while (arch_spin_is_locked(lock))
+ u32 val = READ_ONCE(lock->lock);
+ u32 curr = arch_spin_current(val);
+
+ /* Return immediately if unlocked. */
+ if (arch_spin_next(val) == curr)
+ return;
+
+ /* Wait until the current locker has released the lock. */
+ do {
delay_backoff(iterations++);
+ } while (arch_spin_current(READ_ONCE(lock->lock)) == curr);
}
EXPORT_SYMBOL(arch_spin_unlock_wait);
/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
/*
- * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
- * It returns the length, including the terminating NUL, or zero on exception.
- * If length is greater than the bound, returns one plus the bound.
- */
-STD_ENTRY(strnlen_user_asm)
- { bz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
-1: { lb_u r4, r0; addi r1, r1, -1 }
- bz r4, 2f
- { bnzt r1, 1b; addi r0, r0, 1 }
-2: { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strnlen_user_asm)
- .pushsection .fixup,"ax"
-strnlen_user_fault:
- { move r0, zero; jrp lr }
- ENDPROC(strnlen_user_fault)
- .section __ex_table,"a"
- .align 4
- .word 1b, strnlen_user_fault
- .popsection
-
-/*
- * strncpy_from_user_asm takes the kernel target pointer in r0,
- * the userspace source pointer in r1, and the length bound (including
- * the trailing NUL) in r2. On success, it returns the string length
- * (not including the trailing NUL), or -EFAULT on failure.
- */
-STD_ENTRY(strncpy_from_user_asm)
- { bz r2, 2f; move r3, r0 }
-1: { lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
- { sb r0, r4; addi r0, r0, 1 }
- bz r4, 2f
- bnzt r2, 1b
- { sub r0, r0, r3; jrp lr }
-2: addi r0, r0, -1 /* don't count the trailing NUL */
- { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strncpy_from_user_asm)
- .pushsection .fixup,"ax"
-strncpy_from_user_fault:
- { movei r0, -EFAULT; jrp lr }
- ENDPROC(strncpy_from_user_fault)
- .section __ex_table,"a"
- .align 4
- .word 1b, strncpy_from_user_fault
- .popsection
-
-/*
* clear_user_asm takes the user target address in r0 and the
* number of bytes to zero in r1.
* It returns the number of uncopiable bytes (hopefully zero) in r0.
/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
/*
- * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
- * It returns the length, including the terminating NUL, or zero on exception.
- * If length is greater than the bound, returns one plus the bound.
- */
-STD_ENTRY(strnlen_user_asm)
- { beqz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
-1: { ld1u r4, r0; addi r1, r1, -1 }
- beqz r4, 2f
- { bnezt r1, 1b; addi r0, r0, 1 }
-2: { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strnlen_user_asm)
- .pushsection .fixup,"ax"
-strnlen_user_fault:
- { move r0, zero; jrp lr }
- ENDPROC(strnlen_user_fault)
- .section __ex_table,"a"
- .align 8
- .quad 1b, strnlen_user_fault
- .popsection
-
-/*
- * strncpy_from_user_asm takes the kernel target pointer in r0,
- * the userspace source pointer in r1, and the length bound (including
- * the trailing NUL) in r2. On success, it returns the string length
- * (not including the trailing NUL), or -EFAULT on failure.
- */
-STD_ENTRY(strncpy_from_user_asm)
- { beqz r2, 2f; move r3, r0 }
-1: { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
- { st1 r0, r4; addi r0, r0, 1 }
- beqz r4, 2f
- bnezt r2, 1b
- { sub r0, r0, r3; jrp lr }
-2: addi r0, r0, -1 /* don't count the trailing NUL */
- { sub r0, r0, r3; jrp lr }
- STD_ENDPROC(strncpy_from_user_asm)
- .pushsection .fixup,"ax"
-strncpy_from_user_fault:
- { movei r0, -EFAULT; jrp lr }
- ENDPROC(strncpy_from_user_fault)
- .section __ex_table,"a"
- .align 8
- .quad 1b, strncpy_from_user_fault
- .popsection
-
-/*
* clear_user_asm takes the user target address in r0 and the
* number of bytes to zero in r1.
* It returns the number of uncopiable bytes (hopefully zero) in r0.
* interrupt away appropriately and return immediately. We can't do
* page faults for user code while in kernel mode.
*/
-void do_page_fault(struct pt_regs *regs, int fault_num,
- unsigned long address, unsigned long write)
+static inline void __do_page_fault(struct pt_regs *regs, int fault_num,
+ unsigned long address, unsigned long write)
{
int is_page_fault;
- enum ctx_state prev_state = exception_enter();
#ifdef CONFIG_KPROBES
/*
*/
if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
regs->faultnum, SIGSEGV) == NOTIFY_STOP)
- goto done;
+ return;
#endif
#ifdef __tilegx__
async->is_fault = is_page_fault;
async->is_write = write;
async->address = address;
- goto done;
+ return;
}
}
#endif
handle_page_fault(regs, fault_num, is_page_fault, address, write);
+}
-done:
+void do_page_fault(struct pt_regs *regs, int fault_num,
+ unsigned long address, unsigned long write)
+{
+ enum ctx_state prev_state = exception_enter();
+ __do_page_fault(regs, fault_num, address, write);
exception_exit(prev_state);
}
-
#if CHIP_HAS_TILE_DMA()
/*
* This routine effectively re-issues asynchronous page faults
_SIM_CONTROL_OPERATOR_BITS));
return 0;
} else {
- return hv_console_write((HV_VirtAddr)buf, count);
+ /* Translate 0 bytes written to EAGAIN for hvc_console_print. */
+ return hv_console_write((HV_VirtAddr)buf, count) ?: -EAGAIN;
}
}
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