3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu mhiramat@kernel.org
commit 86c0bf8539e7f46d91bd105e55eda96e0064caef upstream.
Fix to show calling lines of inlined functions (where an inline function is called).
die_walk_lines() filtered out the lines inside inlined functions based on the address. However this also filtered out the lines which call those inlined functions from the target function.
To solve this issue, check the call_file and call_line attributes and do not filter out if it matches to the line information.
Without this fix, perf probe -L doesn't show some lines correctly. (don't see the lines after 17)
# perf probe -L vfs_read <vfs_read@/home/mhiramat/ksrc/linux/fs/read_write.c:0> 0 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) 1 { 2 ssize_t ret;
4 if (!(file->f_mode & FMODE_READ)) return -EBADF; 6 if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; 8 if (unlikely(!access_ok(buf, count))) return -EFAULT;
11 ret = rw_verify_area(READ, file, pos, count); 12 if (!ret) { 13 if (count > MAX_RW_COUNT) count = MAX_RW_COUNT; 15 ret = __vfs_read(file, buf, count, pos); 16 if (ret > 0) { fsnotify_access(file); add_rchar(current, ret); }
With this fix:
# perf probe -L vfs_read <vfs_read@/home/mhiramat/ksrc/linux/fs/read_write.c:0> 0 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) 1 { 2 ssize_t ret;
4 if (!(file->f_mode & FMODE_READ)) return -EBADF; 6 if (!(file->f_mode & FMODE_CAN_READ)) return -EINVAL; 8 if (unlikely(!access_ok(buf, count))) return -EFAULT;
11 ret = rw_verify_area(READ, file, pos, count); 12 if (!ret) { 13 if (count > MAX_RW_COUNT) count = MAX_RW_COUNT; 15 ret = __vfs_read(file, buf, count, pos); 16 if (ret > 0) { 17 fsnotify_access(file); 18 add_rchar(current, ret); } 20 inc_syscr(current); }
Fixes: 4cc9cec636e7 ("perf probe: Introduce lines walker interface") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Link: http://lore.kernel.org/lkml/157241937995.32002.17899884017011512577.stgit@de... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- tools/perf/util/dwarf-aux.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
--- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -714,7 +714,7 @@ int die_walk_lines(Dwarf_Die *rt_die, li Dwarf_Lines *lines; Dwarf_Line *line; Dwarf_Addr addr; - const char *fname, *decf = NULL; + const char *fname, *decf = NULL, *inf = NULL; int lineno, ret = 0; int decl = 0, inl; Dwarf_Die die_mem, *cu_die; @@ -765,13 +765,21 @@ int die_walk_lines(Dwarf_Die *rt_die, li */ if (!dwarf_haspc(rt_die, addr)) continue; + if (die_find_inlinefunc(rt_die, addr, &die_mem)) { + /* Call-site check */ + inf = die_get_call_file(&die_mem); + if ((inf && !strcmp(inf, decf)) && + die_get_call_lineno(&die_mem) == lineno) + goto found; + dwarf_decl_line(&die_mem, &inl); if (inl != decl || decf != dwarf_decl_file(&die_mem)) continue; } } +found: /* Get source line */ fname = dwarf_linesrc(line, NULL, NULL);