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-rw-r--r--arch/loongarch/include/asm/unwind.h29
-rw-r--r--arch/loongarch/kernel/Makefile2
-rw-r--r--arch/loongarch/kernel/traps.c3
-rw-r--r--arch/loongarch/kernel/unwind.c32
-rw-r--r--arch/loongarch/kernel/unwind_guess.c52
-rw-r--r--arch/loongarch/kernel/unwind_prologue.c157
6 files changed, 129 insertions, 146 deletions
diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h
index 834ba6bd15d2..36584b95ef8b 100644
--- a/arch/loongarch/include/asm/unwind.h
+++ b/arch/loongarch/include/asm/unwind.h
@@ -27,6 +27,8 @@ struct unwind_state {
unsigned long sp, pc, ra;
};
+bool default_next_frame(struct unwind_state *state);
+
void unwind_start(struct unwind_state *state,
struct task_struct *task, struct pt_regs *regs);
bool unwind_next_frame(struct unwind_state *state);
@@ -50,4 +52,31 @@ static inline unsigned long unwind_graph_addr(struct unwind_state *state,
return ftrace_graph_ret_addr(state->task, &state->graph_idx,
pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET));
}
+
+static __always_inline void __unwind_start(struct unwind_state *state,
+ struct task_struct *task, struct pt_regs *regs)
+{
+ memset(state, 0, sizeof(*state));
+ if (regs) {
+ state->sp = regs->regs[3];
+ state->pc = regs->csr_era;
+ state->ra = regs->regs[1];
+ } else if (task && task != current) {
+ state->sp = thread_saved_fp(task);
+ state->pc = thread_saved_ra(task);
+ state->ra = 0;
+ } else {
+ state->sp = (unsigned long)__builtin_frame_address(0);
+ state->pc = (unsigned long)__builtin_return_address(0);
+ state->ra = 0;
+ }
+ state->task = task;
+ get_stack_info(state->sp, state->task, &state->stack_info);
+ state->pc = unwind_graph_addr(state, state->pc, state->sp);
+}
+
+static __always_inline unsigned long __unwind_get_return_address(struct unwind_state *state)
+{
+ return unwind_done(state) ? 0 : state->pc;
+}
#endif /* _ASM_UNWIND_H */
diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile
index fcaa024a685e..c8cfbd562921 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -8,7 +8,7 @@ extra-y := vmlinux.lds
obj-y += head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \
traps.o irq.o idle.o process.o dma.o mem.o io.o reset.o switch.o \
elf.o syscall.o signal.o time.o topology.o inst.o ptrace.o vdso.o \
- alternative.o unaligned.o
+ alternative.o unaligned.o unwind.o
obj-$(CONFIG_ACPI) += acpi.o
obj-$(CONFIG_EFI) += efi.o
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
index 7ea62faeeadb..c38a146a973b 100644
--- a/arch/loongarch/kernel/traps.c
+++ b/arch/loongarch/kernel/traps.c
@@ -72,9 +72,6 @@ static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
if (!task)
task = current;
- if (user_mode(regs))
- state.type = UNWINDER_GUESS;
-
printk("%sCall Trace:", loglvl);
for (unwind_start(&state, task, pregs);
!unwind_done(&state); unwind_next_frame(&state)) {
diff --git a/arch/loongarch/kernel/unwind.c b/arch/loongarch/kernel/unwind.c
new file mode 100644
index 000000000000..a463d6961344
--- /dev/null
+++ b/arch/loongarch/kernel/unwind.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+
+#include <asm/unwind.h>
+
+bool default_next_frame(struct unwind_state *state)
+{
+ struct stack_info *info = &state->stack_info;
+ unsigned long addr;
+
+ if (unwind_done(state))
+ return false;
+
+ do {
+ for (state->sp += sizeof(unsigned long);
+ state->sp < info->end; state->sp += sizeof(unsigned long)) {
+ addr = *(unsigned long *)(state->sp);
+ state->pc = unwind_graph_addr(state, addr, state->sp + 8);
+ if (__kernel_text_address(state->pc))
+ return true;
+ }
+
+ state->sp = info->next_sp;
+
+ } while (!get_stack_info(state->sp, state->task, info));
+
+ return false;
+}
diff --git a/arch/loongarch/kernel/unwind_guess.c b/arch/loongarch/kernel/unwind_guess.c
index e7e637bdba17..98379b7d4147 100644
--- a/arch/loongarch/kernel/unwind_guess.c
+++ b/arch/loongarch/kernel/unwind_guess.c
@@ -2,41 +2,18 @@
/*
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
-#include <linux/kernel.h>
-#include <linux/ftrace.h>
-
#include <asm/unwind.h>
unsigned long unwind_get_return_address(struct unwind_state *state)
{
- if (unwind_done(state))
- return 0;
-
- return state->pc;
+ return __unwind_get_return_address(state);
}
EXPORT_SYMBOL_GPL(unwind_get_return_address);
void unwind_start(struct unwind_state *state, struct task_struct *task,
struct pt_regs *regs)
{
- memset(state, 0, sizeof(*state));
-
- if (regs) {
- state->sp = regs->regs[3];
- state->pc = regs->csr_era;
- } else if (task && task != current) {
- state->sp = thread_saved_fp(task);
- state->pc = thread_saved_ra(task);
- } else {
- state->sp = (unsigned long)__builtin_frame_address(0);
- state->pc = (unsigned long)__builtin_return_address(0);
- }
-
- state->task = task;
- state->first = true;
- state->pc = unwind_graph_addr(state, state->pc, state->sp);
- get_stack_info(state->sp, state->task, &state->stack_info);
-
+ __unwind_start(state, task, regs);
if (!unwind_done(state) && !__kernel_text_address(state->pc))
unwind_next_frame(state);
}
@@ -44,29 +21,6 @@ EXPORT_SYMBOL_GPL(unwind_start);
bool unwind_next_frame(struct unwind_state *state)
{
- struct stack_info *info = &state->stack_info;
- unsigned long addr;
-
- if (unwind_done(state))
- return false;
-
- if (state->first)
- state->first = false;
-
- do {
- for (state->sp += sizeof(unsigned long);
- state->sp < info->end;
- state->sp += sizeof(unsigned long)) {
- addr = *(unsigned long *)(state->sp);
- state->pc = unwind_graph_addr(state, addr, state->sp + 8);
- if (__kernel_text_address(state->pc))
- return true;
- }
-
- state->sp = info->next_sp;
-
- } while (!get_stack_info(state->sp, state->task, info));
-
- return false;
+ return default_next_frame(state);
}
EXPORT_SYMBOL_GPL(unwind_next_frame);
diff --git a/arch/loongarch/kernel/unwind_prologue.c b/arch/loongarch/kernel/unwind_prologue.c
index 463ba2391bdf..dfc352dba746 100644
--- a/arch/loongarch/kernel/unwind_prologue.c
+++ b/arch/loongarch/kernel/unwind_prologue.c
@@ -19,32 +19,14 @@ static inline void unwind_state_fixup(struct unwind_state *state)
#endif
}
-unsigned long unwind_get_return_address(struct unwind_state *state)
-{
- if (unwind_done(state))
- return 0;
-
- return state->pc;
-}
-EXPORT_SYMBOL_GPL(unwind_get_return_address);
-
-static bool unwind_by_guess(struct unwind_state *state)
-{
- struct stack_info *info = &state->stack_info;
- unsigned long addr;
-
- for (state->sp += sizeof(unsigned long);
- state->sp < info->end;
- state->sp += sizeof(unsigned long)) {
- addr = *(unsigned long *)(state->sp);
- state->pc = unwind_graph_addr(state, addr, state->sp + 8);
- if (__kernel_text_address(state->pc))
- return true;
- }
-
- return false;
-}
-
+/*
+ * LoongArch function prologue is like follows,
+ * [instructions not use stack var]
+ * addi.d sp, sp, -imm
+ * st.d xx, sp, offset <- save callee saved regs and
+ * st.d yy, sp, offset save ra if function is nest.
+ * [others instructions]
+ */
static bool unwind_by_prologue(struct unwind_state *state)
{
long frame_ra = -1;
@@ -91,6 +73,10 @@ static bool unwind_by_prologue(struct unwind_state *state)
ip++;
}
+ /*
+ * Can't find stack alloc action, PC may be in a leaf function. Only the
+ * first being true is reasonable, otherwise indicate analysis is broken.
+ */
if (!frame_size) {
if (state->first)
goto first;
@@ -108,6 +94,7 @@ static bool unwind_by_prologue(struct unwind_state *state)
ip++;
}
+ /* Can't find save $ra action, PC may be in a leaf function, too. */
if (frame_ra < 0) {
if (state->first) {
state->sp = state->sp + frame_size;
@@ -116,96 +103,48 @@ static bool unwind_by_prologue(struct unwind_state *state)
return false;
}
- if (state->first)
- state->first = false;
-
state->pc = *(unsigned long *)(state->sp + frame_ra);
state->sp = state->sp + frame_size;
goto out;
first:
- state->first = false;
- if (state->pc == state->ra)
- return false;
-
state->pc = state->ra;
out:
+ state->first = false;
unwind_state_fixup(state);
return !!__kernel_text_address(state->pc);
}
-void unwind_start(struct unwind_state *state, struct task_struct *task,
- struct pt_regs *regs)
-{
- memset(state, 0, sizeof(*state));
- state->type = UNWINDER_PROLOGUE;
-
- if (regs) {
- state->sp = regs->regs[3];
- state->pc = regs->csr_era;
- state->ra = regs->regs[1];
- if (!__kernel_text_address(state->pc))
- state->type = UNWINDER_GUESS;
- } else if (task && task != current) {
- state->sp = thread_saved_fp(task);
- state->pc = thread_saved_ra(task);
- state->ra = 0;
- } else {
- state->sp = (unsigned long)__builtin_frame_address(0);
- state->pc = (unsigned long)__builtin_return_address(0);
- state->ra = 0;
- }
-
- state->task = task;
- state->first = true;
- state->pc = unwind_graph_addr(state, state->pc, state->sp);
- get_stack_info(state->sp, state->task, &state->stack_info);
-
- if (!unwind_done(state) && !__kernel_text_address(state->pc))
- unwind_next_frame(state);
-}
-EXPORT_SYMBOL_GPL(unwind_start);
-
-bool unwind_next_frame(struct unwind_state *state)
+static bool next_frame(struct unwind_state *state)
{
- struct stack_info *info = &state->stack_info;
- struct pt_regs *regs;
unsigned long pc;
+ struct pt_regs *regs;
+ struct stack_info *info = &state->stack_info;
if (unwind_done(state))
return false;
do {
- switch (state->type) {
- case UNWINDER_GUESS:
- state->first = false;
- if (unwind_by_guess(state))
- return true;
- break;
-
- case UNWINDER_PROLOGUE:
- if (unwind_by_prologue(state)) {
- state->pc = unwind_graph_addr(state, state->pc, state->sp);
- return true;
- }
+ if (unwind_by_prologue(state)) {
+ state->pc = unwind_graph_addr(state, state->pc, state->sp);
+ return true;
+ }
- if (info->type == STACK_TYPE_IRQ &&
- info->end == state->sp) {
- regs = (struct pt_regs *)info->next_sp;
- pc = regs->csr_era;
+ if (info->type == STACK_TYPE_IRQ && info->end == state->sp) {
+ regs = (struct pt_regs *)info->next_sp;
+ pc = regs->csr_era;
- if (user_mode(regs) || !__kernel_text_address(pc))
- return false;
+ if (user_mode(regs) || !__kernel_text_address(pc))
+ return false;
- state->first = true;
- state->ra = regs->regs[1];
- state->sp = regs->regs[3];
- state->pc = pc;
- get_stack_info(state->sp, state->task, info);
+ state->first = true;
+ state->pc = pc;
+ state->ra = regs->regs[1];
+ state->sp = regs->regs[3];
+ get_stack_info(state->sp, state->task, info);
- return true;
- }
+ return true;
}
state->sp = info->next_sp;
@@ -214,4 +153,36 @@ bool unwind_next_frame(struct unwind_state *state)
return false;
}
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ return __unwind_get_return_address(state);
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs)
+{
+ __unwind_start(state, task, regs);
+ state->type = UNWINDER_PROLOGUE;
+ state->first = true;
+
+ /*
+ * The current PC is not kernel text address, we cannot find its
+ * relative symbol. Thus, prologue analysis will be broken. Luckily,
+ * we can use the default_next_frame().
+ */
+ if (!__kernel_text_address(state->pc)) {
+ state->type = UNWINDER_GUESS;
+ if (!unwind_done(state))
+ unwind_next_frame(state);
+ }
+}
+EXPORT_SYMBOL_GPL(unwind_start);
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ return state->type == UNWINDER_PROLOGUE ?
+ next_frame(state) : default_next_frame(state);
+}
EXPORT_SYMBOL_GPL(unwind_next_frame);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 01:04:24 +0000