From: Masami Hiramatsu (Google) <mhira...@kernel.org>
Add ftrace_fill_perf_regs() which should be compatible with the
perf_fetch_caller_regs(). In other words, the pt_regs returned from the
ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be
used for stack tracing.
Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
---
arch/arm64/include/asm/ftrace.h | 7 +++++++
arch/powerpc/include/asm/ftrace.h | 7 +++++++
arch/s390/include/asm/ftrace.h | 5 +++++
arch/x86/include/asm/ftrace.h | 7 +++++++
include/linux/ftrace.h | 31 +++++++++++++++++++++++++++++++
5 files changed, 57 insertions(+)
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
index 5ad24f315d52..5fbe8fe3e8a5 100644
--- a/arch/arm64/include/asm/ftrace.h
+++ b/arch/arm64/include/asm/ftrace.h
@@ -148,6 +148,13 @@ ftrace_partial_regs(const struct ftrace_regs *fregs,
struct pt_regs *regs)
return regs;
}
+#define arch_ftrace_fill_perf_regs(fregs, _regs) do { \
+ (_regs)->pc = (fregs)->pc; \
+ (_regs)->regs[29] = (fregs)->fp; \
+ (_regs)->sp = (fregs)->sp; \
+ (_regs)->pstate = PSR_MODE_EL1h; \
+ } while (0)
+
int ftrace_regs_query_register_offset(const char *name);
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
diff --git a/arch/powerpc/include/asm/ftrace.h
b/arch/powerpc/include/asm/ftrace.h
index 9e5a39b6a311..53fa39ef476b 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -52,6 +52,13 @@ static __always_inline struct pt_regs
*arch_ftrace_get_regs(struct ftrace_regs *
return fregs->regs.msr ? &fregs->regs : NULL;
}
+#define arch_ftrace_fill_perf_regs(fregs, _regs) do { \
+ (_regs)->result = 0; \
+ (_regs)->nip = (fregs)->regs.nip; \
+ (_regs)->gpr[1] = (fregs)->regs.gpr[1]; \
+ asm volatile("mfmsr %0" : "=r" ((_regs)->msr)); \
+ } while (0)
+
static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
unsigned long ip)
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 6de3bf4d0092..94ceb9564d44 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -99,6 +99,11 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs
*fregs,
#define ftrace_regs_query_register_offset(name) \
regs_query_register_offset(name)
+#define arch_ftrace_fill_perf_regs(fregs, _regs) do { \
+ (_regs)->psw.addr = (fregs)->regs.psw.addr; \
+ (_regs)->gprs[15] = (fregs)->regs.gprs[15]; \
+ } while (0)
+
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 897cf02c20b1..800c2af8af01 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -48,6 +48,13 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs)
return &fregs->regs;
}
+#define arch_ftrace_fill_perf_regs(fregs, _regs) do { \
+ (_regs)->ip = (fregs)->regs.ip; \
+ (_regs)->sp = (fregs)->regs.sp; \
+ (_regs)->cs = __KERNEL_CS; \
+ (_regs)->flags = 0; \
+ } while (0)
+
#define ftrace_regs_set_instruction_pointer(fregs, _ip) \
do { (fregs)->regs.ip = (_ip); } while (0)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 819511ab75b7..962c3e6c5e3b 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -190,6 +190,37 @@ ftrace_partial_regs(struct ftrace_regs *fregs, struct
pt_regs *regs)
#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS ||
CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST */
+#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
+
+/*
+ * Please define arch dependent pt_regs which compatible to the
+ * perf_arch_fetch_caller_regs() but based on ftrace_regs.
+ * This requires
+ * - user_mode(_regs) returns false (always kernel mode).
+ * - able to use the _regs for stack trace.
+ */
+#ifndef arch_ftrace_fill_perf_regs
+/* As same as perf_arch_fetch_caller_regs(), do nothing by default */
+#define arch_ftrace_fill_perf_regs(fregs, _regs) do {} while (0)
+#endif
+
+static __always_inline struct pt_regs *
+ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs)
+{
+ arch_ftrace_fill_perf_regs(fregs, regs);
+ return regs;
+}
+
+#else /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
+
+static __always_inline struct pt_regs *
+ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs)
+{
+ return &fregs->regs;
+}
+
+#endif
+
/*
* When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
* Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
