[PATCH] scripts/faddr2line: show the code context

From: changbin . du
Date: Mon Mar 19 2018 - 03:33:01 EST


From: Changbin Du <changbin.du@xxxxxxxxx>

Inspired by gdb command 'list', show the code context of target lines.
Here is a example:

$ scripts/faddr2line vmlinux native_write_msr+0x6
native_write_msr+0x6/0x20:
arch_static_branch at arch/x86/include/asm/msr.h:105
100 return EAX_EDX_VAL(val, low, high);
101 }
102
103 static inline void notrace __wrmsr(unsigned int msr, u32 low, u32 high)
104 {
105 asm volatile("1: wrmsr\n"
106 "2:\n"
107 _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_wrmsr_unsafe)
108 : : "c" (msr), "a"(low), "d" (high) : "memory");
109 }
110
(inlined by) static_key_false at include/linux/jump_label.h:142
137 #define JUMP_TYPE_LINKED 2UL
138 #define JUMP_TYPE_MASK 3UL
139
140 static __always_inline bool static_key_false(struct static_key *key)
141 {
142 return arch_static_branch(key, false);
143 }
144
145 static __always_inline bool static_key_true(struct static_key *key)
146 {
147 return !arch_static_branch(key, true);
(inlined by) native_write_msr at arch/x86/include/asm/msr.h:150
145 static inline void notrace
146 native_write_msr(unsigned int msr, u32 low, u32 high)
147 {
148 __wrmsr(msr, low, high);
149
150 if (msr_tracepoint_active(__tracepoint_write_msr))
151 do_trace_write_msr(msr, ((u64)high << 32 | low), 0);
152 }
153
154 /* Can be uninlined because referenced by paravirt */
155 static inline int notrace

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
scripts/faddr2line | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/scripts/faddr2line b/scripts/faddr2line
index 7721d5b..9e5735a 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -163,7 +163,17 @@ __faddr2line() {

# pass real address to addr2line
echo "$func+$offset/$sym_size:"
- ${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;"
+ local file_lines=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
+ [[ -z $file_lines ]] && return
+
+ # show each line with context
+ echo "$file_lines" | while read -r line
+ do
+ echo $line
+ eval $(echo $line | awk -F "[ :]" '{printf("n1=%d;n2=%d;f=%s",$NF-5, $NF+5, $(NF-1))}')
+ awk 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") {printf("%d\t%s\n", NR, $0)}' $f
+ done
+
DONE=1

done < <(${NM} -n $objfile | awk -v fn=$func -v end=$file_end '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, "0x"$1 } END {if (found == 1) print line, end; }')
--
2.7.4