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dc9a5d2ccd
Fix to get the declared file name even if it uses file index 0
in DWARF5, using custom die_get_decl_file() function.
Actually, the DWARF5 standard says file index 0 of the DW_AT_decl_file
is invalid(1), but there is a discussion and maybe this will be updated
[2].
Anyway, clang generates such DWARF5 file for the linux kernel. Thus it
must be handled.
Without this, 'perf probe' returns an error:
$ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
Debuginfo analysis failed.
Error: Failed to show lines.
With this, it can handle the case correctly:
$ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
<vfs_read@$SRC_PATH/fs/read_write.c:10>
11 ret = rw_verify_area(READ, file, pos, count);
12 if (ret)
return ret;
[1] DWARF5 specification 2.14 says "The value 0 indicates that no source file has been specified.")
[2] http://wiki.dwarfstd.org/index.php?title=DWARF5_Line_Table_File_Numbers)
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/166731052936.2100653.13380621874859467731.stgit@devnote3
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.