scripts/faddr2line: show the code context

scripts/faddr2line: show the code context

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

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Changbin Du <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Kate Stewart <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>