typedef struct thread_struct thread_struct;
-/*
- * Stack layout of a C stack frame.
- */
-#ifndef __PACK_STACK
-struct stack_frame {
- unsigned long back_chain;
- unsigned long empty1[5];
- unsigned long gprs[10];
- unsigned int empty2[8];
-};
-#else
-struct stack_frame {
- unsigned long empty1[5];
- unsigned int empty2[8];
- unsigned long gprs[10];
- unsigned long back_chain;
-};
-#endif
-
#define ARCH_MIN_TASKALIGN 8
#define INIT_THREAD { \
struct seq_file;
struct pt_regs;
-typedef int (*dump_trace_func_t)(void *data, unsigned long address, int reliable);
-void dump_trace(dump_trace_func_t func, void *data,
- struct task_struct *task, unsigned long sp);
void show_registers(struct pt_regs *regs);
-
void show_cacheinfo(struct seq_file *m);
/* Free all resources held by a thread. */
return cpu_address;
}
-#define CALL_ARGS_0() \
- register unsigned long r2 asm("2")
-#define CALL_ARGS_1(arg1) \
- register unsigned long r2 asm("2") = (unsigned long)(arg1)
-#define CALL_ARGS_2(arg1, arg2) \
- CALL_ARGS_1(arg1); \
- register unsigned long r3 asm("3") = (unsigned long)(arg2)
-#define CALL_ARGS_3(arg1, arg2, arg3) \
- CALL_ARGS_2(arg1, arg2); \
- register unsigned long r4 asm("4") = (unsigned long)(arg3)
-#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \
- CALL_ARGS_3(arg1, arg2, arg3); \
- register unsigned long r4 asm("5") = (unsigned long)(arg4)
-#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
- CALL_ARGS_4(arg1, arg2, arg3, arg4); \
- register unsigned long r4 asm("6") = (unsigned long)(arg5)
-
-#define CALL_FMT_0 "=&d" (r2) :
-#define CALL_FMT_1 "+&d" (r2) :
-#define CALL_FMT_2 CALL_FMT_1 "d" (r3),
-#define CALL_FMT_3 CALL_FMT_2 "d" (r4),
-#define CALL_FMT_4 CALL_FMT_3 "d" (r5),
-#define CALL_FMT_5 CALL_FMT_4 "d" (r6),
-
-#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
-#define CALL_CLOBBER_4 CALL_CLOBBER_5
-#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
-#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
-#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
-#define CALL_CLOBBER_0 CALL_CLOBBER_1
-
-#define CALL_ON_STACK(fn, stack, nr, args...) \
-({ \
- CALL_ARGS_##nr(args); \
- unsigned long prev; \
- \
- asm volatile( \
- " la %[_prev],0(15)\n" \
- " la 15,0(%[_stack])\n" \
- " stg %[_prev],%[_bc](15)\n" \
- " brasl 14,%[_fn]\n" \
- " la 15,0(%[_prev])\n" \
- : [_prev] "=&a" (prev), CALL_FMT_##nr \
- [_stack] "a" (stack), \
- [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
- [_fn] "X" (fn) : CALL_CLOBBER_##nr); \
- r2; \
-})
-
/*
* Give up the time slice of the virtual PU.
*/
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_STACKTRACE_H
+#define _ASM_S390_STACKTRACE_H
+
+#include <linux/uaccess.h>
+#include <linux/ptrace.h>
+#include <asm/switch_to.h>
+
+enum stack_type {
+ STACK_TYPE_UNKNOWN,
+ STACK_TYPE_TASK,
+ STACK_TYPE_IRQ,
+ STACK_TYPE_NODAT,
+ STACK_TYPE_RESTART,
+};
+
+struct stack_info {
+ enum stack_type type;
+ unsigned long begin, end;
+};
+
+const char *stack_type_name(enum stack_type type);
+int get_stack_info(unsigned long sp, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask);
+
+static inline bool on_stack(struct stack_info *info,
+ unsigned long addr, size_t len)
+{
+ if (info->type == STACK_TYPE_UNKNOWN)
+ return false;
+ if (addr + len < addr)
+ return false;
+ return addr >= info->begin && addr + len < info->end;
+}
+
+static inline unsigned long get_stack_pointer(struct task_struct *task,
+ struct pt_regs *regs)
+{
+ if (regs)
+ return (unsigned long) kernel_stack_pointer(regs);
+ if (task == current)
+ return current_stack_pointer();
+ return (unsigned long) task->thread.ksp;
+}
+
+/*
+ * Stack layout of a C stack frame.
+ */
+#ifndef __PACK_STACK
+struct stack_frame {
+ unsigned long back_chain;
+ unsigned long empty1[5];
+ unsigned long gprs[10];
+ unsigned int empty2[8];
+};
+#else
+struct stack_frame {
+ unsigned long empty1[5];
+ unsigned int empty2[8];
+ unsigned long gprs[10];
+ unsigned long back_chain;
+};
+#endif
+
+#define CALL_ARGS_0() \
+ register unsigned long r2 asm("2")
+#define CALL_ARGS_1(arg1) \
+ register unsigned long r2 asm("2") = (unsigned long)(arg1)
+#define CALL_ARGS_2(arg1, arg2) \
+ CALL_ARGS_1(arg1); \
+ register unsigned long r3 asm("3") = (unsigned long)(arg2)
+#define CALL_ARGS_3(arg1, arg2, arg3) \
+ CALL_ARGS_2(arg1, arg2); \
+ register unsigned long r4 asm("4") = (unsigned long)(arg3)
+#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \
+ CALL_ARGS_3(arg1, arg2, arg3); \
+ register unsigned long r4 asm("5") = (unsigned long)(arg4)
+#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
+ CALL_ARGS_4(arg1, arg2, arg3, arg4); \
+ register unsigned long r4 asm("6") = (unsigned long)(arg5)
+
+#define CALL_FMT_0 "=&d" (r2) :
+#define CALL_FMT_1 "+&d" (r2) :
+#define CALL_FMT_2 CALL_FMT_1 "d" (r3),
+#define CALL_FMT_3 CALL_FMT_2 "d" (r4),
+#define CALL_FMT_4 CALL_FMT_3 "d" (r5),
+#define CALL_FMT_5 CALL_FMT_4 "d" (r6),
+
+#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
+#define CALL_CLOBBER_4 CALL_CLOBBER_5
+#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
+#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
+#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
+#define CALL_CLOBBER_0 CALL_CLOBBER_1
+
+#define CALL_ON_STACK(fn, stack, nr, args...) \
+({ \
+ CALL_ARGS_##nr(args); \
+ unsigned long prev; \
+ \
+ asm volatile( \
+ " la %[_prev],0(15)\n" \
+ " la 15,0(%[_stack])\n" \
+ " stg %[_prev],%[_bc](15)\n" \
+ " brasl 14,%[_fn]\n" \
+ " la 15,0(%[_prev])\n" \
+ : [_prev] "=&a" (prev), CALL_FMT_##nr \
+ [_stack] "a" (stack), \
+ [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
+ [_fn] "X" (fn) : CALL_CLOBBER_##nr); \
+ r2; \
+})
+
+#endif /* _ASM_S390_STACKTRACE_H */
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_UNWIND_H
+#define _ASM_S390_UNWIND_H
+
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+
+/*
+ * To use the stack unwinder it has to be initialized with unwind_start.
+ * There four combinations for task and regs:
+ * 1) task==NULL, regs==NULL: the unwind starts for the task that is currently
+ * running, sp/ip picked up from the CPU registers
+ * 2) task==NULL, regs!=NULL: the unwind starts from the sp/ip found in
+ * the struct pt_regs of an interrupt frame for the current task
+ * 3) task!=NULL, regs==NULL: the unwind starts for an inactive task with
+ * the sp picked up from task->thread.ksp and the ip picked up from the
+ * return address stored by __switch_to
+ * 4) task!=NULL, regs!=NULL: the sp/ip are picked up from the interrupt
+ * frame 'regs' of a inactive task
+ * If 'first_frame' is not zero unwind_start skips unwind frames until it
+ * reaches the specified stack pointer.
+ * The end of the unwinding is indicated with unwind_done, this can be true
+ * right after unwind_start, e.g. with first_frame!=0 that can not be found.
+ * unwind_next_frame skips to the next frame.
+ * Once the unwind is completed unwind_error() can be used to check if there
+ * has been a situation where the unwinder could not correctly understand
+ * the tasks call chain.
+ */
+
+struct unwind_state {
+ struct stack_info stack_info;
+ unsigned long stack_mask;
+ struct task_struct *task;
+ struct pt_regs *regs;
+ unsigned long sp, ip;
+ int graph_idx;
+ bool reliable;
+ bool error;
+};
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long first_frame);
+bool unwind_next_frame(struct unwind_state *state);
+unsigned long unwind_get_return_address(struct unwind_state *state);
+
+static inline bool unwind_done(struct unwind_state *state)
+{
+ return state->stack_info.type == STACK_TYPE_UNKNOWN;
+}
+
+static inline bool unwind_error(struct unwind_state *state)
+{
+ return state->error;
+}
+
+static inline void unwind_start(struct unwind_state *state,
+ struct task_struct *task,
+ struct pt_regs *regs,
+ unsigned long sp)
+{
+ sp = sp ? : get_stack_pointer(task, regs);
+ __unwind_start(state, task, regs, sp);
+}
+
+static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
+{
+ return unwind_done(state) ? NULL : state->regs;
+}
+
+#define unwind_for_each_frame(state, task, regs, first_frame) \
+ for (unwind_start(state, task, regs, first_frame); \
+ !unwind_done(state); \
+ unwind_next_frame(state))
+
+static inline void unwind_init(void) {}
+static inline void unwind_module_init(struct module *mod, void *orc_ip,
+ size_t orc_ip_size, void *orc,
+ size_t orc_size) {}
+
+#ifdef CONFIG_KASAN
+/*
+ * This disables KASAN checking when reading a value from another task's stack,
+ * since the other task could be running on another CPU and could have poisoned
+ * the stack in the meantime.
+ */
+#define READ_ONCE_TASK_STACK(task, x) \
+({ \
+ unsigned long val; \
+ if (task == current) \
+ val = READ_ONCE(x); \
+ else \
+ val = READ_ONCE_NOCHECK(x); \
+ val; \
+})
+#else
+#define READ_ONCE_TASK_STACK(task, x) READ_ONCE(x)
+#endif
+
+#endif /* _ASM_S390_UNWIND_H */
#
CFLAGS_stacktrace.o += -fno-optimize-sibling-calls
CFLAGS_dumpstack.o += -fno-optimize-sibling-calls
+CFLAGS_unwind_bc.o += -fno-optimize-sibling-calls
#
# Pass UTS_MACHINE for user_regset definition
obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
-obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o
+obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
extra-y += head64.o vmlinux.lds
#include <asm/pgtable.h>
#include <asm/gmap.h>
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
int main(void)
{
#include <asm/debug.h>
#include <asm/dis.h>
#include <asm/ipl.h>
+#include <asm/unwind.h>
-/*
- * For dump_trace we have tree different stack to consider:
- * - the panic stack which is used if the kernel stack has overflown
- * - the asynchronous interrupt stack (cpu related)
- * - the synchronous kernel stack (process related)
- * The stack trace can start at any of the three stacks and can potentially
- * touch all of them. The order is: panic stack, async stack, sync stack.
- */
-static unsigned long __no_sanitize_address
-__dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
- unsigned long low, unsigned long high)
+const char *stack_type_name(enum stack_type type)
{
- struct stack_frame *sf;
- struct pt_regs *regs;
-
- while (1) {
- if (sp < low || sp > high - sizeof(*sf))
- return sp;
- sf = (struct stack_frame *) sp;
- if (func(data, sf->gprs[8], 0))
- return sp;
- /* Follow the backchain. */
- while (1) {
- low = sp;
- sp = sf->back_chain;
- if (!sp)
- break;
- if (sp <= low || sp > high - sizeof(*sf))
- return sp;
- sf = (struct stack_frame *) sp;
- if (func(data, sf->gprs[8], 1))
- return sp;
- }
- /* Zero backchain detected, check for interrupt frame. */
- sp = (unsigned long) (sf + 1);
- if (sp <= low || sp > high - sizeof(*regs))
- return sp;
- regs = (struct pt_regs *) sp;
- if (!user_mode(regs)) {
- if (func(data, regs->psw.addr, 1))
- return sp;
- }
- low = sp;
- sp = regs->gprs[15];
+ switch (type) {
+ case STACK_TYPE_TASK:
+ return "task";
+ case STACK_TYPE_IRQ:
+ return "irq";
+ case STACK_TYPE_NODAT:
+ return "nodat";
+ case STACK_TYPE_RESTART:
+ return "restart";
+ default:
+ return "unknown";
}
}
-void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
- unsigned long sp)
+static inline bool in_stack(unsigned long sp, struct stack_info *info,
+ enum stack_type type, unsigned long low,
+ unsigned long high)
+{
+ if (sp < low || sp >= high)
+ return false;
+ info->type = type;
+ info->begin = low;
+ info->end = high;
+ return true;
+}
+
+static bool in_task_stack(unsigned long sp, struct task_struct *task,
+ struct stack_info *info)
+{
+ unsigned long stack;
+
+ stack = (unsigned long) task_stack_page(task);
+ return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
+}
+
+static bool in_irq_stack(unsigned long sp, struct stack_info *info)
{
- unsigned long frame_size;
+ unsigned long frame_size, top;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
-#ifdef CONFIG_CHECK_STACK
- sp = __dump_trace(func, data, sp,
- S390_lowcore.nodat_stack + frame_size - THREAD_SIZE,
- S390_lowcore.nodat_stack + frame_size);
-#endif
- sp = __dump_trace(func, data, sp,
- S390_lowcore.async_stack + frame_size - THREAD_SIZE,
- S390_lowcore.async_stack + frame_size);
- task = task ?: current;
- __dump_trace(func, data, sp,
- (unsigned long)task_stack_page(task),
- (unsigned long)task_stack_page(task) + THREAD_SIZE);
+ top = S390_lowcore.async_stack + frame_size;
+ return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
+}
+
+static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
+{
+ unsigned long frame_size, top;
+
+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+ top = S390_lowcore.nodat_stack + frame_size;
+ return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
}
-EXPORT_SYMBOL_GPL(dump_trace);
-static int show_address(void *data, unsigned long address, int reliable)
+static bool in_restart_stack(unsigned long sp, struct stack_info *info)
{
- if (reliable)
- printk(" [<%016lx>] %pSR \n", address, (void *)address);
- else
- printk("([<%016lx>] %pSR)\n", address, (void *)address);
+ unsigned long frame_size, top;
+
+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+ top = S390_lowcore.restart_stack + frame_size;
+ return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
+}
+
+int get_stack_info(unsigned long sp, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask)
+{
+ if (!sp)
+ goto unknown;
+
+ task = task ? : current;
+
+ /* Check per-task stack */
+ if (in_task_stack(sp, task, info))
+ goto recursion_check;
+
+ if (task != current)
+ goto unknown;
+
+ /* Check per-cpu stacks */
+ if (!in_irq_stack(sp, info) &&
+ !in_nodat_stack(sp, info) &&
+ !in_restart_stack(sp, info))
+ goto unknown;
+
+recursion_check:
+ /*
+ * Make sure we don't iterate through any given stack more than once.
+ * If it comes up a second time then there's something wrong going on:
+ * just break out and report an unknown stack type.
+ */
+ if (*visit_mask & (1UL << info->type)) {
+ printk_deferred_once(KERN_WARNING
+ "WARNING: stack recursion on stack type %d\n",
+ info->type);
+ goto unknown;
+ }
+ *visit_mask |= 1UL << info->type;
return 0;
+unknown:
+ info->type = STACK_TYPE_UNKNOWN;
+ return -EINVAL;
}
void show_stack(struct task_struct *task, unsigned long *stack)
{
- unsigned long sp = (unsigned long) stack;
+ struct unwind_state state;
- if (!sp)
- sp = task ? task->thread.ksp : current_stack_pointer();
printk("Call Trace:\n");
- dump_trace(show_address, NULL, task, sp);
if (!task)
task = current;
- debug_show_held_locks(task);
+ unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
+ printk(state.reliable ? " [<%016lx>] %pSR \n" :
+ "([<%016lx>] %pSR)\n",
+ state.ip, (void *) state.ip);
+ debug_show_held_locks(task ? : current);
}
static void show_last_breaking_event(struct pt_regs *regs)
#include <asm/lowcore.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>
+#include <asm/stacktrace.h>
#include "entry.h"
DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
#include <asm/cacheflush.h>
#include <asm/os_info.h>
#include <asm/set_memory.h>
+#include <asm/stacktrace.h>
#include <asm/switch_to.h>
#include <asm/nmi.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sysinfo.h>
+#include <asm/unwind.h>
const char *perf_pmu_name(void)
{
}
arch_initcall(service_level_perf_register);
-static int __perf_callchain_kernel(void *data, unsigned long address, int reliable)
-{
- struct perf_callchain_entry_ctx *entry = data;
-
- perf_callchain_store(entry, address);
- return 0;
-}
-
void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
- if (user_mode(regs))
- return;
- dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]);
+ struct unwind_state state;
+
+ unwind_for_each_frame(&state, current, regs, 0)
+ perf_callchain_store(entry, state.ip);
}
/* Perf definitions for PMU event attributes in sysfs */
#include <asm/irq.h>
#include <asm/nmi.h>
#include <asm/smp.h>
+#include <asm/stacktrace.h>
#include <asm/switch_to.h>
#include <asm/runtime_instr.h>
#include "entry.h"
#include <asm/diag.h>
#include <asm/os_info.h>
#include <asm/sclp.h>
+#include <asm/stacktrace.h>
#include <asm/sysinfo.h>
#include <asm/numa.h>
#include <asm/alternative.h>
#include <asm/sigp.h>
#include <asm/idle.h>
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
#include <asm/topology.h>
#include "entry.h"
#include <linux/stacktrace.h>
#include <linux/kallsyms.h>
#include <linux/export.h>
-
-static int __save_address(void *data, unsigned long address, int nosched)
-{
- struct stack_trace *trace = data;
-
- if (nosched && in_sched_functions(address))
- return 0;
- if (trace->skip > 0) {
- trace->skip--;
- return 0;
- }
- if (trace->nr_entries < trace->max_entries) {
- trace->entries[trace->nr_entries++] = address;
- return 0;
- }
- return 1;
-}
-
-static int save_address(void *data, unsigned long address, int reliable)
-{
- return __save_address(data, address, 0);
-}
-
-static int save_address_nosched(void *data, unsigned long address, int reliable)
-{
- return __save_address(data, address, 1);
-}
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
void save_stack_trace(struct stack_trace *trace)
{
- unsigned long sp;
+ struct unwind_state state;
- sp = current_stack_pointer();
- dump_trace(save_address, trace, NULL, sp);
+ unwind_for_each_frame(&state, current, NULL, 0) {
+ if (trace->nr_entries >= trace->max_entries)
+ break;
+ if (trace->skip > 0)
+ trace->skip--;
+ else
+ trace->entries[trace->nr_entries++] = state.ip;
+ }
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
- unsigned long sp;
+ struct unwind_state state;
- sp = tsk->thread.ksp;
- if (tsk == current)
- sp = current_stack_pointer();
- dump_trace(save_address_nosched, trace, tsk, sp);
+ unwind_for_each_frame(&state, tsk, NULL, 0) {
+ if (trace->nr_entries >= trace->max_entries)
+ break;
+ if (in_sched_functions(state.ip))
+ continue;
+ if (trace->skip > 0)
+ trace->skip--;
+ else
+ trace->entries[trace->nr_entries++] = state.ip;
+ }
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
- unsigned long sp;
+ struct unwind_state state;
- sp = kernel_stack_pointer(regs);
- dump_trace(save_address, trace, NULL, sp);
+ unwind_for_each_frame(&state, current, regs, 0) {
+ if (trace->nr_entries >= trace->max_entries)
+ break;
+ if (trace->skip > 0)
+ trace->skip--;
+ else
+ trace->entries[trace->nr_entries++] = state.ip;
+ }
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/sched.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/interrupt.h>
+#include <asm/sections.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ if (unwind_done(state))
+ return 0;
+ return __kernel_text_address(state->ip) ? state->ip : 0;
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+static bool outside_of_stack(struct unwind_state *state, unsigned long sp)
+{
+ return (sp <= state->sp) ||
+ (sp + sizeof(struct stack_frame) > state->stack_info.end);
+}
+
+static bool update_stack_info(struct unwind_state *state, unsigned long sp)
+{
+ struct stack_info *info = &state->stack_info;
+ unsigned long *mask = &state->stack_mask;
+
+ /* New stack pointer leaves the current stack */
+ if (get_stack_info(sp, state->task, info, mask) != 0 ||
+ !on_stack(info, sp, sizeof(struct stack_frame)))
+ /* 'sp' does not point to a valid stack */
+ return false;
+ return true;
+}
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ struct stack_info *info = &state->stack_info;
+ struct stack_frame *sf;
+ struct pt_regs *regs;
+ unsigned long sp, ip;
+ bool reliable;
+
+ regs = state->regs;
+ if (unlikely(regs)) {
+ sp = READ_ONCE_TASK_STACK(state->task, regs->gprs[15]);
+ if (unlikely(outside_of_stack(state, sp))) {
+ if (!update_stack_info(state, sp))
+ goto out_err;
+ }
+ sf = (struct stack_frame *) sp;
+ ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ reliable = false;
+ regs = NULL;
+ } else {
+ sf = (struct stack_frame *) state->sp;
+ sp = READ_ONCE_TASK_STACK(state->task, sf->back_chain);
+ if (likely(sp)) {
+ /* Non-zero back-chain points to the previous frame */
+ if (unlikely(outside_of_stack(state, sp))) {
+ if (!update_stack_info(state, sp))
+ goto out_err;
+ }
+ sf = (struct stack_frame *) sp;
+ ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ reliable = true;
+ } else {
+ /* No back-chain, look for a pt_regs structure */
+ sp = state->sp + STACK_FRAME_OVERHEAD;
+ if (!on_stack(info, sp, sizeof(struct pt_regs)))
+ goto out_stop;
+ regs = (struct pt_regs *) sp;
+ if (user_mode(regs))
+ goto out_stop;
+ ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr);
+ reliable = true;
+ }
+ }
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ /* Decode any ftrace redirection */
+ if (ip == (unsigned long) return_to_handler)
+ ip = ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ ip, NULL);
+#endif
+
+ /* Update unwind state */
+ state->sp = sp;
+ state->ip = ip;
+ state->regs = regs;
+ state->reliable = reliable;
+ return true;
+
+out_err:
+ state->error = true;
+out_stop:
+ state->stack_info.type = STACK_TYPE_UNKNOWN;
+ return false;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long sp)
+{
+ struct stack_info *info = &state->stack_info;
+ unsigned long *mask = &state->stack_mask;
+ struct stack_frame *sf;
+ unsigned long ip;
+ bool reliable;
+
+ memset(state, 0, sizeof(*state));
+ state->task = task;
+ state->regs = regs;
+
+ /* Don't even attempt to start from user mode regs: */
+ if (regs && user_mode(regs)) {
+ info->type = STACK_TYPE_UNKNOWN;
+ return;
+ }
+
+ /* Get current stack pointer and initialize stack info */
+ if (get_stack_info(sp, task, info, mask) != 0 ||
+ !on_stack(info, sp, sizeof(struct stack_frame))) {
+ /* Something is wrong with the stack pointer */
+ info->type = STACK_TYPE_UNKNOWN;
+ state->error = true;
+ return;
+ }
+
+ /* Get the instruction pointer from pt_regs or the stack frame */
+ if (regs) {
+ ip = READ_ONCE_TASK_STACK(state->task, regs->psw.addr);
+ reliable = true;
+ } else {
+ sf = (struct stack_frame *) sp;
+ ip = READ_ONCE_TASK_STACK(state->task, sf->gprs[8]);
+ reliable = false;
+ }
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ /* Decode any ftrace redirection */
+ if (ip == (unsigned long) return_to_handler)
+ ip = ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ ip, NULL);
+#endif
+
+ /* Update unwind state */
+ state->sp = sp;
+ state->ip = ip;
+ state->reliable = reliable;
+}
+EXPORT_SYMBOL_GPL(__unwind_start);
#include <linux/cpu.h>
#include <asm/ctl_reg.h>
#include <asm/io.h>
+#include <asm/stacktrace.h>
static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
{
#include <linux/oprofile.h>
#include <linux/init.h>
#include <asm/processor.h>
-
-static int __s390_backtrace(void *data, unsigned long address, int reliable)
-{
- unsigned int *depth = data;
-
- if (*depth == 0)
- return 1;
- (*depth)--;
- oprofile_add_trace(address);
- return 0;
-}
+#include <asm/unwind.h>
static void s390_backtrace(struct pt_regs *regs, unsigned int depth)
{
- if (user_mode(regs))
- return;
- dump_trace(__s390_backtrace, &depth, NULL, regs->gprs[15]);
+ struct unwind_state state;
+
+ unwind_for_each_frame(&state, current, regs, 0) {
+ if (depth-- == 0)
+ break;
+ oprofile_add_trace(state.ip);
+ }
}
int __init oprofile_arch_init(struct oprofile_operations *ops)
projects / linux.git / commitdiff