Commit 05a8256c authored by Linus Torvalds's avatar Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

Pull arch/tile updates from Chris Metcalf:
 "These are a grab bag of changes to improve debugging and respond to a
  variety of issues raised on LKML over the last couple of months"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: avoid a "label not used" warning in do_page_fault()
  tile: vdso: use raw_read_seqcount_begin() in vdso
  tile: force CONFIG_TILEGX if ARCH != tilepro
  tile: improve stack backtrace
  tile: fix "odd fault" warning for stack backtraces
  tile: set up initial stack top to honor STACK_TOP_DELTA
  tile: support delivering NMIs for multicore backtrace
  drivers/tty/hvc/hvc_tile.c: properly return -EAGAIN
  tile: add <asm/word-at-a-time.h> and enable support functions
  tile: use READ_ONCE() in arch_spin_is_locked()
  tile: modify arch_spin_unlock_wait() semantics
parents 0161b6e0 5316a64c
......@@ -24,11 +24,14 @@ config TILE
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
......@@ -125,8 +128,10 @@ config HVC_TILE
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
......
......@@ -78,4 +78,9 @@ void tile_irq_activate(unsigned int irq, int tile_irq_type);
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 */
......@@ -111,8 +111,6 @@ struct thread_struct {
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()
......
......@@ -41,8 +41,12 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock)
* 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);
......
......@@ -18,6 +18,8 @@
#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
......@@ -44,7 +46,8 @@ static inline u32 arch_spin_next(u32 val)
/* 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);
}
......
......@@ -58,17 +58,14 @@ extern int KBacktraceIterator_end(struct KBacktraceIterator *kbt);
/* 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 */
......@@ -42,6 +42,7 @@ struct thread_info {
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? */
};
/*
......
......@@ -52,6 +52,14 @@ void do_timer_interrupt(struct pt_regs *, int fault_num);
/* 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);
......
......@@ -64,6 +64,13 @@ static inline int is_arch_mappable_range(unsigned long addr,
#define is_arch_mappable_range(addr, size) 0
#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.
......@@ -471,62 +478,9 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
#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.
......
#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 */
......@@ -321,8 +321,11 @@
/** 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__
......@@ -1253,6 +1256,11 @@ void hv_downcall_dispatch(void);
#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__
......@@ -1780,6 +1788,56 @@ int hv_dev_poll(int devhdl, __hv32 events, HV_IntArg intarg);
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
......
......@@ -27,13 +27,6 @@ STD_ENTRY(current_text_addr)
{ 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 - . }
......
......@@ -71,4 +71,5 @@ gensym hv_flush_all, 0x6e0, 32
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
......@@ -75,6 +75,7 @@
#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
......@@ -134,6 +135,7 @@
#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
......@@ -264,3 +266,5 @@ HV_WRAP9(int, hv_flush_remote, HV_PhysAddr, cache_pa,
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)
......@@ -515,6 +515,10 @@ intvec_\vecname:
.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
......@@ -1571,3 +1575,5 @@ intrpt_start:
/* 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
......@@ -27,6 +27,7 @@
#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>
......@@ -132,7 +133,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
(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;
}
......@@ -546,31 +546,141 @@ void exit_thread(void)
#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;
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();
}
dump_stack_regs(regs);
#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_ */
......@@ -71,7 +71,7 @@ static unsigned long __initdata node_percpu[MAX_NUMNODES];
* 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;
......
......@@ -23,6 +23,7 @@
#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>
......@@ -109,7 +110,7 @@ static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt)
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;
......@@ -119,10 +120,12 @@ static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt)
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 */
......@@ -131,7 +134,7 @@ static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt,
{
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();
......@@ -151,11 +154,6 @@ static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt,
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;
......@@ -178,7 +176,7 @@ static int KBacktraceIterator_next_item_inclusive(
{
for (;;) {
do {
if (!KBacktraceIterator_is_sigreturn(kbt))
if (!is_sigreturn(kbt))
return KBT_ONGOING;
} while (backtrace_next(&kbt->it));
......@@ -357,51 +355,50 @@ static void describe_addr(struct KBacktraceIterator *kbt,
*/
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));
......@@ -416,24 +413,12 @@ void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
}
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)
{
......@@ -445,11 +430,15 @@ static struct pt_regs *regs_to_pt_regs(struct pt_regs *regs,
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(&regs, pc, lr, sp, r52));
regs_to_pt_regs(&regs, pc, lr, sp, r52);
KBacktraceIterator_init(&kbt, NULL, &regs);
tile_show_stack(&kbt);
}
/* This is called from KBacktraceIterator_init_current() */
......@@ -461,22 +450,30 @@ void _KBacktraceIterator_init_current(struct KBacktraceIterator *kbt, ulong pc,
regs_to_pt_regs(&regs, 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;
......@@ -484,31 +481,57 @@ void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace)
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 */
......
......@@ -395,6 +395,21 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
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);
......
......@@ -67,7 +67,7 @@ static inline int do_realtime(struct vdso_data *vdso, struct timespec *ts)
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);
......@@ -86,7 +86,7 @@ static inline int do_monotonic(struct vdso_data *vdso, struct timespec *ts)
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);
......@@ -105,7 +105,7 @@ static inline int do_realtime_coarse(struct vdso_data *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)));
......@@ -119,7 +119,7 @@ static inline int do_monotonic_coarse(struct vdso_data *vdso,
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)));
......@@ -137,7 +137,7 @@ struct syscall_return_value __vdso_gettimeofday(struct timeval *tv,
/* 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)));
......
......@@ -18,8 +18,6 @@
/* 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);
......@@ -28,7 +26,6 @@ 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);
......
......@@ -65,8 +65,17 @@ EXPORT_SYMBOL(arch_spin_trylock);
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);
......
......@@ -65,8 +65,17 @@ EXPORT_SYMBOL(arch_spin_trylock);
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);
......
......@@ -19,52 +19,6 @@
/* 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.
......
......@@ -19,52 +19,6 @@
/* 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.
......
......@@ -699,11 +699,10 @@ struct intvec_state do_page_fault_ics(struct pt_regs *regs, int fault_num,
* 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,
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
/*
......@@ -713,7 +712,7 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
*/
if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
regs->faultnum, SIGSEGV) == NOTIFY_STOP)
goto done;
return;
#endif
#ifdef __tilegx__
......@@ -835,18 +834,22 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
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
......
......@@ -51,7 +51,8 @@ int tile_console_write(const char *buf, int count)
_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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