Functions to walk stack and print backtrace. The stack's unadorned as
STACK: addr addr addr ...
A follow-up patch post-processes the output to pretty-print the stack.
Stack walker is just a stub on arm and ppc.
Signed-off-by: Peter Feiner <pfeiner@xxxxxxxxxx>
---
Makefile | 3 ++-
arm/Makefile.common | 1 +
lib/arm/dump_stack.c | 6 ++++++
lib/libcflat.h | 4 ++++
lib/powerpc/dump_stack.c | 6 ++++++
lib/printf.c | 37 +++++++++++++++++++++++++++++++++++++
lib/x86/dump_stack.c | 24 ++++++++++++++++++++++++
powerpc/Makefile.common | 1 +
x86/Makefile.common | 4 ++++
9 files changed, 85 insertions(+), 1 deletion(-)
create mode 100644 lib/arm/dump_stack.c
create mode 100644 lib/powerpc/dump_stack.c
create mode 100644 lib/x86/dump_stack.c
diff --git a/Makefile b/Makefile
index ddba941..40ea4ec 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,8 @@ cc-option = $(shell if $(CC) $(1) -S -o /dev/null -xc /dev/null \
CFLAGS += -g
CFLAGS += $(autodepend-flags) -Wall
-CFLAGS += $(call cc-option, -fomit-frame-pointer, "")
+frame-pointer-flag=-f$(if $(KEEP_FRAME_POINTER),no-,)omit-frame-pointer
+CFLAGS += $(call cc-option, $(frame-pointer-flag), "")
CFLAGS += $(call cc-option, -fno-stack-protector, "")
CFLAGS += $(call cc-option, -fno-stack-protector-all, "")
diff --git a/arm/Makefile.common b/arm/Makefile.common
index dd3a0ca..054bdee 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -39,6 +39,7 @@ cflatobjs += lib/arm/mmu.o
cflatobjs += lib/arm/bitops.o
cflatobjs += lib/arm/psci.o
cflatobjs += lib/arm/smp.o
+cflatobjs += lib/arm/dump_stack.o
libeabi = lib/arm/libeabi.a
eabiobjs = lib/arm/eabi_compat.o
diff --git a/lib/arm/dump_stack.c b/lib/arm/dump_stack.c
new file mode 100644
index 0000000..528ba63
--- /dev/null
+++ b/lib/arm/dump_stack.c
@@ -0,0 +1,6 @@
+#include "libcflat.h"
+
+int walk_stack(unsigned long bp, unsigned long *stack, int max_depth)
+{
+ return 0;
+}
diff --git a/lib/libcflat.h b/lib/libcflat.h
index 1f0049c..42c94df 100644
--- a/lib/libcflat.h
+++ b/lib/libcflat.h
@@ -65,6 +65,10 @@ extern void report_xfail(const char *msg_fmt, bool xfail, bool pass, ...);
extern void report_abort(const char *msg_fmt, ...);
extern int report_summary(void);
+int walk_stack(unsigned long bp, unsigned long *stack, int max_depth);
+void dump_stack(unsigned long ip, unsigned long bp);
+void dump_current_stack(void);
+
#define ARRAY_SIZE(_a) (sizeof(_a)/sizeof((_a)[0]))
#define container_of(ptr, type, member) ({ \
diff --git a/lib/powerpc/dump_stack.c b/lib/powerpc/dump_stack.c
new file mode 100644
index 0000000..528ba63
--- /dev/null
+++ b/lib/powerpc/dump_stack.c
@@ -0,0 +1,6 @@
+#include "libcflat.h"
+
+int walk_stack(unsigned long bp, unsigned long *stack, int max_depth)
+{
+ return 0;
+}
diff --git a/lib/printf.c b/lib/printf.c
index 2aec59a..e97fca9 100644
--- a/lib/printf.c
+++ b/lib/printf.c
@@ -259,3 +259,40 @@ int printf(const char *fmt, ...)
puts(buf);
return r;
}
+
+static void print_stack(unsigned long *stack, int depth,
+ bool top_is_return_address)
+{
+ int i;
+
+ printf("\tSTACK: " );
+ for (i = 0; i < depth; i++) {
+ int offset = -1;
+ if (i == 0 && !top_is_return_address)
+ offset = 0;
+ printf(" %lx", stack[i] + offset);
+ }
+ printf("\n");
+}
+
+#define MAX_DEPTH 10
+
+void dump_stack(unsigned long ip, unsigned long bp)
+{
+ unsigned long stack[MAX_DEPTH];
+ int depth;
+
+ stack[0] = ip;
+ depth = walk_stack(bp, &stack[1], MAX_DEPTH - 1);
+ print_stack(stack, depth + 1, false);
+}
+
+void dump_current_stack(void)
+{
+ unsigned long stack[MAX_DEPTH];
+ int depth;
+
+ depth = walk_stack((unsigned long)__builtin_frame_address(1), stack,
+ MAX_DEPTH);
+ print_stack(stack, depth, true);
+}
diff --git a/lib/x86/dump_stack.c b/lib/x86/dump_stack.c
new file mode 100644
index 0000000..6e9d126
--- /dev/null
+++ b/lib/x86/dump_stack.c
@@ -0,0 +1,24 @@
+#include "libcflat.h"
+
+int walk_stack(unsigned long bp, unsigned long *stack, int max_depth)
+{
+ static int walking;
+ int depth = 0;
+ unsigned long *frame = (unsigned long *) bp;
+
+ if (walking) {
+ printf("RECURSIVE STACK WALK!!!\n");
+ return 0;
+ }
+ walking = 1;
+
+ for (depth = 0; depth < max_depth; depth++) {
+ stack[depth] = frame[1];
+ if (stack[depth] == 0)
+ break;
+ frame = (unsigned long *) frame[0];
+ }
+
+ walking = 0;
+ return depth;
+}
diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
index 2ce6494..694dea0 100644
--- a/powerpc/Makefile.common
+++ b/powerpc/Makefile.common
@@ -30,6 +30,7 @@ cflatobjs += lib/powerpc/io.o
cflatobjs += lib/powerpc/hcall.o
cflatobjs += lib/powerpc/setup.o
cflatobjs += lib/powerpc/rtas.o
+cflatobjs += lib/powerpc/dump_stack.o
FLATLIBS = $(libcflat) $(LIBFDT_archive)
%.elf: CFLAGS += $(arch_CFLAGS)
diff --git a/x86/Makefile.common b/x86/Makefile.common
index 3a14fea..d7c7eab 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -12,6 +12,7 @@ cflatobjs += lib/x86/atomic.o
cflatobjs += lib/x86/desc.o
cflatobjs += lib/x86/isr.o
cflatobjs += lib/x86/acpi.o
+cflatobjs += lib/x86/dump_stack.o
$(libcflat): LDFLAGS += -nostdlib
$(libcflat): CFLAGS += -ffreestanding -I lib
@@ -19,6 +20,9 @@ $(libcflat): CFLAGS += -ffreestanding -I lib
CFLAGS += -m$(bits)
CFLAGS += -O1
+# dump_stack.o relies on frame pointers.
+KEEP_FRAME_POINTER := y
+
libgcc := $(shell $(CC) -m$(bits) --print-libgcc-file-name)
FLATLIBS = lib/libcflat.a $(libgcc)
--
2.7.0.rc3.207.g0ac5344
--
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