[PATCH] elf-reader: reclaim fd and mem before break

[Xiaole He <hexiaole1994@126.com>]

In 'src/abg-elf-reader.cc':

/* src/abg-elf-reader.cc begin */
1  void
2  locate_alt_ctf_debug_info()
3  {
4      ...
5      for (const auto& path : rdr.debug_info_root_paths())
6      {
7          ...
8          int fd;
9          if ((fd = open(file_path.c_str(), O_RDONLY)) == -1)
10             continue;
11
12         ...
13         Elf *hdl;
14         if ((hdl = elf_begin(fd, ELF_C_READ, nullptr)) == nullptr)
15             ...
16
17         alt_ctf_section =
18             elf_helpers::find_section(hdl, ".ctf", SHT_PROGBITS);
19         break;
20
21         elf_end(hdl);
22         close(fd);
23     }
24     ...
25 }
/* src/abg-elf-reader.cc end */

The file descriptor 'fd' and the memory that 'hdl' pointed to can have
a chance where they were only created but nerver been destroyed when
above code reach the line 19. Thus cause the leakage of file descriptor
and memory.

This leakage problem had already occured on our system, and the problem
finally cause process can not open any more file and complaint
'Errno 24: Too many open files'.

This patch fix above problem.

        * src/abg-elf-reader.cc (locate_alt_ctf_debug_info):
        reclaim fd and mem before break.

Signed-off-by: Xiaole He <hexiaole@kylinos.cn>
---
 src/abg-elf-reader.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/abg-elf-reader.cc b/src/abg-elf-reader.cc
index c07f0655..979f0aae 100644
--- a/src/abg-elf-reader.cc
+++ b/src/abg-elf-reader.cc
@@ -453,10 +453,10 @@ struct reader::priv
 	  // unlikely .ctf was designed to be present in stripped file
 	  alt_ctf_section =
 	    elf_helpers::find_section(hdl, ".ctf", SHT_PROGBITS);
-          break;
 
 	  elf_end(hdl);
 	  close(fd);
+          break;
 	}
   }
 
-- 
2.27.0