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authorJinyang He <hejinyang@loongson.cn>2023-01-17 06:42:16 +0300
committerHuacai Chen <chenhuacai@loongson.cn>2023-01-17 06:42:16 +0300
commit5bb8d34449c4a2eb94d657b992170afafac274f9 (patch)
tree4f63968d33455e8d61c205c9e957bf93e02b9cc8 /arch
parent429a9671f235c94fc4b5d6687308714b74adc820 (diff)
downloadlinux-5bb8d34449c4a2eb94d657b992170afafac274f9.tar.xz
LoongArch: Use correct sp value to get graph addr in stack unwinders
The stack frame when function_graph enable like follows, --------- <- function sp_on_entry | | | FAKE_RA <- sp_on_entry - sizeof(pt_regs) + PT_R1 | --------- <- sp_on_entry - sizeof(pt_regs) So if we want to get the &FAKE_RA we should get sp_on_entry first. In the unwinder_prologue case, we can get the sp_on_entry as state->sp, because we try to calculate each CFA and the ra saved address. But in the unwinder_guess case, we cannot get it because we do not try to calculate the CFA. Although LoongArch have not fixed frame, the $ra is saved at CFA - 8 in most cases, we can try guess, too. As we store the pc in state, we not need to dereference state->sp, too. Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch')
-rw-r--r--arch/loongarch/include/asm/ftrace.h2
-rw-r--r--arch/loongarch/include/asm/unwind.h10
-rw-r--r--arch/loongarch/kernel/unwind_guess.c11
-rw-r--r--arch/loongarch/kernel/unwind_prologue.c21
4 files changed, 20 insertions, 24 deletions
diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
index 90f9d3399b2a..3418d32d4fc7 100644
--- a/arch/loongarch/include/asm/ftrace.h
+++ b/arch/loongarch/include/asm/ftrace.h
@@ -10,8 +10,6 @@
#define FTRACE_REGS_PLT_IDX 1
#define NR_FTRACE_PLTS 2
-#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1]))
-
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h
index f2b52b9ea93d..834ba6bd15d2 100644
--- a/arch/loongarch/include/asm/unwind.h
+++ b/arch/loongarch/include/asm/unwind.h
@@ -8,7 +8,9 @@
#define _ASM_UNWIND_H
#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
#include <asm/stacktrace.h>
enum unwinder_type {
@@ -40,4 +42,12 @@ static inline bool unwind_error(struct unwind_state *state)
return state->error;
}
+#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1]))
+
+static inline unsigned long unwind_graph_addr(struct unwind_state *state,
+ unsigned long pc, unsigned long cfa)
+{
+ return ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET));
+}
#endif /* _ASM_UNWIND_H */
diff --git a/arch/loongarch/kernel/unwind_guess.c b/arch/loongarch/kernel/unwind_guess.c
index 9ef5f2a47f88..e7e637bdba17 100644
--- a/arch/loongarch/kernel/unwind_guess.c
+++ b/arch/loongarch/kernel/unwind_guess.c
@@ -11,10 +11,8 @@ unsigned long unwind_get_return_address(struct unwind_state *state)
{
if (unwind_done(state))
return 0;
- else if (state->first)
- return state->pc;
- return *(unsigned long *)(state->sp);
+ return state->pc;
}
EXPORT_SYMBOL_GPL(unwind_get_return_address);
@@ -36,7 +34,7 @@ void unwind_start(struct unwind_state *state, struct task_struct *task,
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))
@@ -60,9 +58,8 @@ bool unwind_next_frame(struct unwind_state *state)
state->sp < info->end;
state->sp += sizeof(unsigned long)) {
addr = *(unsigned long *)(state->sp);
- state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
- addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
- if (__kernel_text_address(addr))
+ state->pc = unwind_graph_addr(state, addr, state->sp + 8);
+ if (__kernel_text_address(state->pc))
return true;
}
diff --git a/arch/loongarch/kernel/unwind_prologue.c b/arch/loongarch/kernel/unwind_prologue.c
index 613545ce6a97..463ba2391bdf 100644
--- a/arch/loongarch/kernel/unwind_prologue.c
+++ b/arch/loongarch/kernel/unwind_prologue.c
@@ -21,16 +21,10 @@ static inline void unwind_state_fixup(struct unwind_state *state)
unsigned long unwind_get_return_address(struct unwind_state *state)
{
-
if (unwind_done(state))
return 0;
- else if (state->type)
- return state->pc;
- else if (state->first)
- return state->pc;
-
- return *(unsigned long *)(state->sp);
+ return state->pc;
}
EXPORT_SYMBOL_GPL(unwind_get_return_address);
@@ -43,9 +37,8 @@ static bool unwind_by_guess(struct unwind_state *state)
state->sp < info->end;
state->sp += sizeof(unsigned long)) {
addr = *(unsigned long *)(state->sp);
- state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
- addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
- if (__kernel_text_address(addr))
+ state->pc = unwind_graph_addr(state, addr, state->sp + 8);
+ if (__kernel_text_address(state->pc))
return true;
}
@@ -166,7 +159,7 @@ void unwind_start(struct unwind_state *state, struct task_struct *task,
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))
@@ -193,8 +186,7 @@ bool unwind_next_frame(struct unwind_state *state)
case UNWINDER_PROLOGUE:
if (unwind_by_prologue(state)) {
- state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
- state->pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
+ state->pc = unwind_graph_addr(state, state->pc, state->sp);
return true;
}
@@ -209,8 +201,7 @@ bool unwind_next_frame(struct unwind_state *state)
state->first = true;
state->ra = regs->regs[1];
state->sp = regs->regs[3];
- state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
- pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
+ state->pc = pc;
get_stack_info(state->sp, state->task, info);
return true;