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-rw-r--r--arch/x86/kernel/Makefile5
-rw-r--r--arch/x86/kernel/ftrace_64.S24
-rw-r--r--arch/x86/kernel/unwind_orc.c48
-rw-r--r--include/linux/ftrace.h2
-rw-r--r--kernel/trace/ftrace.c29
-rw-r--r--kernel/trace/trace.c34
-rw-r--r--kernel/trace/trace_events_trigger.c13
-rw-r--r--kernel/trace/trace_functions.c49
8 files changed, 152 insertions, 52 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 81bb565f4497..7e2baf7304ae 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -29,10 +29,13 @@ KASAN_SANITIZE_stacktrace.o := n
KASAN_SANITIZE_paravirt.o := n
OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y
-OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y
OBJECT_FILES_NON_STANDARD_test_nx.o := y
OBJECT_FILES_NON_STANDARD_paravirt_patch_$(BITS).o := y
+ifdef CONFIG_FRAME_POINTER
+OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y
+endif
+
# If instrumentation of this dir is enabled, boot hangs during first second.
# Probably could be more selective here, but note that files related to irqs,
# boot, dumpstack/stacktrace, etc are either non-interesting or can lead to
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 7cb8ba08beb9..ef61f540cf0a 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -8,6 +8,7 @@
#include <asm/ftrace.h>
#include <asm/export.h>
#include <asm/nospec-branch.h>
+#include <asm/unwind_hints.h>
.code64
.section .entry.text, "ax"
@@ -20,7 +21,6 @@ EXPORT_SYMBOL(__fentry__)
EXPORT_SYMBOL(mcount)
#endif
-/* All cases save the original rbp (8 bytes) */
#ifdef CONFIG_FRAME_POINTER
# ifdef CC_USING_FENTRY
/* Save parent and function stack frames (rip and rbp) */
@@ -31,7 +31,7 @@ EXPORT_SYMBOL(mcount)
# endif
#else
/* No need to save a stack frame */
-# define MCOUNT_FRAME_SIZE 8
+# define MCOUNT_FRAME_SIZE 0
#endif /* CONFIG_FRAME_POINTER */
/* Size of stack used to save mcount regs in save_mcount_regs */
@@ -64,10 +64,10 @@ EXPORT_SYMBOL(mcount)
*/
.macro save_mcount_regs added=0
- /* Always save the original rbp */
+#ifdef CONFIG_FRAME_POINTER
+ /* Save the original rbp */
pushq %rbp
-#ifdef CONFIG_FRAME_POINTER
/*
* Stack traces will stop at the ftrace trampoline if the frame pointer
* is not set up properly. If fentry is used, we need to save a frame
@@ -105,7 +105,11 @@ EXPORT_SYMBOL(mcount)
* Save the original RBP. Even though the mcount ABI does not
* require this, it helps out callers.
*/
+#ifdef CONFIG_FRAME_POINTER
movq MCOUNT_REG_SIZE-8(%rsp), %rdx
+#else
+ movq %rbp, %rdx
+#endif
movq %rdx, RBP(%rsp)
/* Copy the parent address into %rsi (second parameter) */
@@ -148,7 +152,7 @@ EXPORT_SYMBOL(mcount)
ENTRY(function_hook)
retq
-END(function_hook)
+ENDPROC(function_hook)
ENTRY(ftrace_caller)
/* save_mcount_regs fills in first two parameters */
@@ -184,7 +188,7 @@ GLOBAL(ftrace_graph_call)
/* This is weak to keep gas from relaxing the jumps */
WEAK(ftrace_stub)
retq
-END(ftrace_caller)
+ENDPROC(ftrace_caller)
ENTRY(ftrace_regs_caller)
/* Save the current flags before any operations that can change them */
@@ -255,7 +259,7 @@ GLOBAL(ftrace_regs_caller_end)
jmp ftrace_epilogue
-END(ftrace_regs_caller)
+ENDPROC(ftrace_regs_caller)
#else /* ! CONFIG_DYNAMIC_FTRACE */
@@ -313,9 +317,10 @@ ENTRY(ftrace_graph_caller)
restore_mcount_regs
retq
-END(ftrace_graph_caller)
+ENDPROC(ftrace_graph_caller)
-GLOBAL(return_to_handler)
+ENTRY(return_to_handler)
+ UNWIND_HINT_EMPTY
subq $24, %rsp
/* Save the return values */
@@ -330,4 +335,5 @@ GLOBAL(return_to_handler)
movq (%rsp), %rax
addq $24, %rsp
JMP_NOSPEC %rdi
+END(return_to_handler)
#endif
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index be86a865087a..1f9188f5357c 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -74,8 +74,50 @@ static struct orc_entry *orc_module_find(unsigned long ip)
}
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+static struct orc_entry *orc_find(unsigned long ip);
+
+/*
+ * Ftrace dynamic trampolines do not have orc entries of their own.
+ * But they are copies of the ftrace entries that are static and
+ * defined in ftrace_*.S, which do have orc entries.
+ *
+ * If the undwinder comes across a ftrace trampoline, then find the
+ * ftrace function that was used to create it, and use that ftrace
+ * function's orc entrie, as the placement of the return code in
+ * the stack will be identical.
+ */
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+ struct ftrace_ops *ops;
+ unsigned long caller;
+
+ ops = ftrace_ops_trampoline(ip);
+ if (!ops)
+ return NULL;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ caller = (unsigned long)ftrace_regs_call;
+ else
+ caller = (unsigned long)ftrace_call;
+
+ /* Prevent unlikely recursion */
+ if (ip == caller)
+ return NULL;
+
+ return orc_find(caller);
+}
+#else
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+ return NULL;
+}
+#endif
+
static struct orc_entry *orc_find(unsigned long ip)
{
+ static struct orc_entry *orc;
+
if (!orc_init)
return NULL;
@@ -111,7 +153,11 @@ static struct orc_entry *orc_find(unsigned long ip)
__stop_orc_unwind_ip - __start_orc_unwind_ip, ip);
/* Module lookup: */
- return orc_module_find(ip);
+ orc = orc_module_find(ip);
+ if (orc)
+ return orc;
+
+ return orc_ftrace_find(ip);
}
static void orc_sort_swap(void *_a, void *_b, int size)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 2bab81951ced..3319df9727aa 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -332,6 +332,8 @@ extern int ftrace_text_reserved(const void *start, const void *end);
extern int ftrace_nr_registered_ops(void);
+struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
+
bool is_ftrace_trampoline(unsigned long addr);
/*
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ccdf3664e4a9..554b517c61a0 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1119,15 +1119,11 @@ static struct ftrace_ops global_ops = {
};
/*
- * This is used by __kernel_text_address() to return true if the
- * address is on a dynamically allocated trampoline that would
- * not return true for either core_kernel_text() or
- * is_module_text_address().
+ * Used by the stack undwinder to know about dynamic ftrace trampolines.
*/
-bool is_ftrace_trampoline(unsigned long addr)
+struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
{
- struct ftrace_ops *op;
- bool ret = false;
+ struct ftrace_ops *op = NULL;
/*
* Some of the ops may be dynamically allocated,
@@ -1144,15 +1140,24 @@ bool is_ftrace_trampoline(unsigned long addr)
if (op->trampoline && op->trampoline_size)
if (addr >= op->trampoline &&
addr < op->trampoline + op->trampoline_size) {
- ret = true;
- goto out;
+ preempt_enable_notrace();
+ return op;
}
} while_for_each_ftrace_op(op);
-
- out:
preempt_enable_notrace();
- return ret;
+ return NULL;
+}
+
+/*
+ * This is used by __kernel_text_address() to return true if the
+ * address is on a dynamically allocated trampoline that would
+ * not return true for either core_kernel_text() or
+ * is_module_text_address().
+ */
+bool is_ftrace_trampoline(unsigned long addr)
+{
+ return ftrace_ops_trampoline(addr) != NULL;
}
struct ftrace_page {
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2a8d8a294345..8e3f20a18a06 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2374,6 +2374,15 @@ void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
}
EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
+/*
+ * Skip 3:
+ *
+ * trace_buffer_unlock_commit_regs()
+ * trace_event_buffer_commit()
+ * trace_event_raw_event_xxx()
+*/
+# define STACK_SKIP 3
+
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct ring_buffer *buffer,
struct ring_buffer_event *event,
@@ -2383,16 +2392,12 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
__buffer_unlock_commit(buffer, event);
/*
- * If regs is not set, then skip the following callers:
- * trace_buffer_unlock_commit_regs
- * event_trigger_unlock_commit
- * trace_event_buffer_commit
- * trace_event_raw_event_sched_switch
+ * If regs is not set, then skip the necessary functions.
* Note, we can still get here via blktrace, wakeup tracer
* and mmiotrace, but that's ok if they lose a function or
- * two. They are that meaningful.
+ * two. They are not that meaningful.
*/
- ftrace_trace_stack(tr, buffer, flags, regs ? 0 : 4, pc, regs);
+ ftrace_trace_stack(tr, buffer, flags, regs ? 0 : STACK_SKIP, pc, regs);
ftrace_trace_userstack(buffer, flags, pc);
}
@@ -2579,11 +2584,13 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
trace.skip = skip;
/*
- * Add two, for this function and the call to save_stack_trace()
+ * Add one, for this function and the call to save_stack_trace()
* If regs is set, then these functions will not be in the way.
*/
+#ifndef CONFIG_UNWINDER_ORC
if (!regs)
- trace.skip += 2;
+ trace.skip++;
+#endif
/*
* Since events can happen in NMIs there's no safe way to
@@ -2711,11 +2718,10 @@ void trace_dump_stack(int skip)
local_save_flags(flags);
- /*
- * Skip 3 more, seems to get us at the caller of
- * this function.
- */
- skip += 3;
+#ifndef CONFIG_UNWINDER_ORC
+ /* Skip 1 to skip this function. */
+ skip++;
+#endif
__ftrace_trace_stack(global_trace.trace_buffer.buffer,
flags, skip, preempt_count(), NULL);
}
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index f2ac9d44f6c4..87411482a46f 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1123,13 +1123,22 @@ static __init int register_trigger_snapshot_cmd(void) { return 0; }
#endif /* CONFIG_TRACER_SNAPSHOT */
#ifdef CONFIG_STACKTRACE
+#ifdef CONFIG_UNWINDER_ORC
+/* Skip 2:
+ * event_triggers_post_call()
+ * trace_event_raw_event_xxx()
+ */
+# define STACK_SKIP 2
+#else
/*
- * Skip 3:
+ * Skip 4:
* stacktrace_trigger()
* event_triggers_post_call()
+ * trace_event_buffer_commit()
* trace_event_raw_event_xxx()
*/
-#define STACK_SKIP 3
+#define STACK_SKIP 4
+#endif
static void
stacktrace_trigger(struct event_trigger_data *data, void *rec)
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 27f7ad12c4b1..b611cd36e22d 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -154,6 +154,24 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
preempt_enable_notrace();
}
+#ifdef CONFIG_UNWINDER_ORC
+/*
+ * Skip 2:
+ *
+ * function_stack_trace_call()
+ * ftrace_call()
+ */
+#define STACK_SKIP 2
+#else
+/*
+ * Skip 3:
+ * __trace_stack()
+ * function_stack_trace_call()
+ * ftrace_call()
+ */
+#define STACK_SKIP 3
+#endif
+
static void
function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
@@ -180,15 +198,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
if (likely(disabled == 1)) {
pc = preempt_count();
trace_function(tr, ip, parent_ip, flags, pc);
- /*
- * skip over 5 funcs:
- * __ftrace_trace_stack,
- * __trace_stack,
- * function_stack_trace_call
- * ftrace_list_func
- * ftrace_call
- */
- __trace_stack(tr, flags, 5, pc);
+ __trace_stack(tr, flags, STACK_SKIP, pc);
}
atomic_dec(&data->disabled);
@@ -367,14 +377,27 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
tracer_tracing_off(tr);
}
+#ifdef CONFIG_UNWINDER_ORC
/*
- * Skip 4:
+ * Skip 3:
+ *
+ * function_trace_probe_call()
+ * ftrace_ops_assist_func()
+ * ftrace_call()
+ */
+#define FTRACE_STACK_SKIP 3
+#else
+/*
+ * Skip 5:
+ *
+ * __trace_stack()
* ftrace_stacktrace()
* function_trace_probe_call()
- * ftrace_ops_list_func()
+ * ftrace_ops_assist_func()
* ftrace_call()
*/
-#define STACK_SKIP 4
+#define FTRACE_STACK_SKIP 5
+#endif
static __always_inline void trace_stack(struct trace_array *tr)
{
@@ -384,7 +407,7 @@ static __always_inline void trace_stack(struct trace_array *tr)
local_save_flags(flags);
pc = preempt_count();
- __trace_stack(tr, flags, STACK_SKIP, pc);
+ __trace_stack(tr, flags, FTRACE_STACK_SKIP, pc);
}
static void
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-06 14:35:19 +0000