diff mbox series

powerpc: Use the correct flag for 32-bit known libraries

Message ID 20211022211201.983646-1-lamm@linux.ibm.com
State Rejected
Headers show
Series powerpc: Use the correct flag for 32-bit known libraries | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686
codonell/TryBot-64bit success Build for 64bit

Commit Message

Lucas A. M. Magalhaes Oct. 22, 2021, 9:12 p.m. UTC
In systems with more versions of the known libraries, i.e. on IBM
Advance Toolchain, ldconfig will order them incorrectly on ld.cache.

The issue only occurs with 32-bit libraries that don't depend on libc or
libm. That's because process_elf32_file check if the elf depends on one
of the libraries at known_libs to select the elf flag. For example, as
libc.so.6 don't depend on itself or on libm it will be flagged as
FLAG_ELF instead of FLAG_LIBC6 as expected.

This commit fixes this by checking if a appropriate flag was set by
process_elf32_file. If not it will search on known_libs and use the flag
in there.
---
 sysdeps/unix/sysv/linux/powerpc/readelflib.c | 21 +++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

Comments

Florian Weimer Oct. 25, 2021, 6:22 p.m. UTC | #1
* Lucas A. M. Magalhaes via Libc-alpha:

> In systems with more versions of the known libraries, i.e. on IBM
> Advance Toolchain, ldconfig will order them incorrectly on ld.cache.
>
> The issue only occurs with 32-bit libraries that don't depend on libc or
> libm. That's because process_elf32_file check if the elf depends on one
> of the libraries at known_libs to select the elf flag. For example, as
> libc.so.6 don't depend on itself or on libm it will be flagged as
> FLAG_ELF instead of FLAG_LIBC6 as expected.

FLAG_ELF_LIBC6 instead of FLAG_LIBC6.

I have not looked at this patch in detail.  I would prefer if we removed
unified cache support for libc.so.4, libc.so.5 and always wrote
FLAG_ELF_LIBC6 to the cache instead.  The older Linux libcs have been
obsolete for more than twenty years.  I do not know how much work this
would be, so if someone can review your patch and it can go in, that's
fine with me.

Thanks,
Florian
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/powerpc/readelflib.c b/sysdeps/unix/sysv/linux/powerpc/readelflib.c
index 51f8a9496a..94da21c407 100644
--- a/sysdeps/unix/sysv/linux/powerpc/readelflib.c
+++ b/sysdeps/unix/sysv/linux/powerpc/readelflib.c
@@ -33,11 +33,26 @@  process_elf_file (const char *file_name, const char *lib, int *flag,
 		  char **soname, void *file_contents, size_t file_length)
 {
   ElfW(Ehdr) *elf_header = (ElfW(Ehdr) *) file_contents;
-  int ret;
+  int ret, j;
 
   if (elf_header->e_ident [EI_CLASS] == ELFCLASS32)
-    return process_elf32_file (file_name, lib, flag, osversion, isa_level,
-			       soname, file_contents, file_length);
+    {
+      ret = process_elf32_file (file_name, lib, flag, osversion, isa_level,
+                                soname, file_contents, file_length);
+      /* Use the apropriate flag for known_libs instead of FLAG_ELF.  */
+      if (*flag == FLAG_ELF)
+        {
+          for (j = 0;
+               j < sizeof (known_libs) / sizeof (known_libs [0]);
+               ++j)
+            if (strcmp (lib, known_libs [j].soname) == 0)
+              {
+                *flag = known_libs [j].flag;
+                break;
+              }
+        }
+      return ret;
+    }
   else
     {
       ret = process_elf64_file (file_name, lib, flag, osversion, isa_level,