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authorQing Zhang <zhangqing@loongson.cn>2022-12-10 17:40:21 +0300
committerHuacai Chen <chenhuacai@loongson.cn>2022-12-14 03:41:54 +0300
commita51ac5246d2505b58229242959d2bc73d113ca50 (patch)
treea51e352384af8317ace4baf429c9457ad25d9435 /arch/loongarch
parentac7127e1cc65aeb578998c992a05dbc80fa18f0f (diff)
downloadlinux-a51ac5246d2505b58229242959d2bc73d113ca50.tar.xz
LoongArch/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
ftrace_graph_ret_addr() can be called by stack unwinding code to convert a found stack return address ('ret') to its original value, in case the function graph tracer has modified it to be 'return_to_handler'. If the hasn't been modified, the unchanged value of 'ret' is returned. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch')
-rw-r--r--arch/loongarch/include/asm/ftrace.h3
-rw-r--r--arch/loongarch/include/asm/unwind.h1
-rw-r--r--arch/loongarch/kernel/ftrace_dyn.c2
-rw-r--r--arch/loongarch/kernel/unwind_guess.c4
-rw-r--r--arch/loongarch/kernel/unwind_prologue.c15
5 files changed, 19 insertions, 6 deletions
diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
index ee7feface27a..8c7d137e4871 100644
--- a/arch/loongarch/include/asm/ftrace.h
+++ b/arch/loongarch/include/asm/ftrace.h
@@ -6,6 +6,8 @@
#ifndef _ASM_LOONGARCH_FTRACE_H
#define _ASM_LOONGARCH_FTRACE_H
+#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 */
@@ -24,6 +26,7 @@ struct dyn_ftrace;
struct dyn_arch_ftrace { };
#define ARCH_SUPPORTS_FTRACE_OPS 1
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ftrace_init_nop ftrace_init_nop
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/asm/unwind.h
index a51eec00efb8..f2b52b9ea93d 100644
--- a/arch/loongarch/include/asm/unwind.h
+++ b/arch/loongarch/include/asm/unwind.h
@@ -21,6 +21,7 @@ struct unwind_state {
struct stack_info stack_info;
struct task_struct *task;
bool first, error, is_ftrace;
+ int graph_idx;
unsigned long sp, pc, ra;
};
diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
index 439ba829b9fd..e23c3be29baa 100644
--- a/arch/loongarch/kernel/ftrace_dyn.c
+++ b/arch/loongarch/kernel/ftrace_dyn.c
@@ -135,7 +135,7 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent)
old = *parent;
- if (!function_graph_enter(old, self_addr, 0, NULL))
+ if (!function_graph_enter(old, self_addr, 0, parent))
*parent = return_hooker;
}
diff --git a/arch/loongarch/kernel/unwind_guess.c b/arch/loongarch/kernel/unwind_guess.c
index 5afa6064d73e..e2d2e4f3001f 100644
--- a/arch/loongarch/kernel/unwind_guess.c
+++ b/arch/loongarch/kernel/unwind_guess.c
@@ -3,6 +3,7 @@
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
#include <linux/kernel.h>
+#include <linux/ftrace.h>
#include <asm/unwind.h>
@@ -53,7 +54,8 @@ 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))
return true;
}
diff --git a/arch/loongarch/kernel/unwind_prologue.c b/arch/loongarch/kernel/unwind_prologue.c
index 46fe344d7fba..0f8d1451ebb8 100644
--- a/arch/loongarch/kernel/unwind_prologue.c
+++ b/arch/loongarch/kernel/unwind_prologue.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
+#include <linux/ftrace.h>
#include <linux/kallsyms.h>
#include <asm/inst.h>
@@ -42,6 +43,8 @@ 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))
return true;
}
@@ -174,8 +177,11 @@ bool unwind_next_frame(struct unwind_state *state)
break;
case UNWINDER_PROLOGUE:
- if (unwind_by_prologue(state))
+ 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));
return true;
+ }
if (info->type == STACK_TYPE_IRQ &&
info->end == state->sp) {
@@ -185,10 +191,11 @@ bool unwind_next_frame(struct unwind_state *state)
if (user_mode(regs) || !__kernel_text_address(pc))
return false;
- state->pc = pc;
- state->sp = regs->regs[3];
- state->ra = regs->regs[1];
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));
get_stack_info(state->sp, state->task, info);
return true;