From: GNU Libc Maintainers <debian-glibc@lists.debian.org>
Date: Mon, 16 Jan 2017 17:43:37 +0000 (+0000)
Subject: local-fptr-table-size
X-Git-Tag: archive/raspbian/2.25-3+rpi1~1^2^2^2^2^2^2^2~155
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=96ff4b9fa820b2658aaa2e9b39be2fffeb407ff0;p=glibc.git

local-fptr-table-size

===================================================================

Gbp-Pq: Topic hppa
Gbp-Pq: Name local-fptr-table-size.diff
---

diff --git a/sysdeps/hppa/dl-fptr.c b/sysdeps/hppa/dl-fptr.c
index 083242b7e..04ed10c82 100644
--- a/sysdeps/hppa/dl-fptr.c
+++ b/sysdeps/hppa/dl-fptr.c
@@ -28,6 +28,7 @@
 #include <dl-fptr.h>
 #include <dl-unmap-segments.h>
 #include <atomic.h>
+#include <libc-internal.h>
 
 #ifndef ELF_MACHINE_BOOT_FPTR_TABLE_LEN
 /* ELF_MACHINE_BOOT_FPTR_TABLE_LEN should be greater than the number of
@@ -181,24 +182,29 @@ make_fdesc (ElfW(Addr) ip, ElfW(Addr) gp)
 static inline ElfW(Addr) * __attribute__ ((always_inline))
 make_fptr_table (struct link_map *map)
 {
-  const ElfW(Sym) *symtab
-    = (const void *) D_PTR (map, l_info[DT_SYMTAB]);
+  const ElfW(Sym) *symtab = (const void *) D_PTR (map, l_info[DT_SYMTAB]);
   const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
   ElfW(Addr) *fptr_table;
   size_t size;
   size_t len;
+  const ElfW(Sym) *symtabend;
 
-  /* XXX Apparently the only way to find out the size of the dynamic
-     symbol section is to assume that the string table follows right
-     afterwards...  */
-  len = ((strtab - (char *) symtab)
+  /* Determine the end of the dynamic symbol table using the hash.  */
+  if (map->l_info[DT_HASH] != NULL)
+    symtabend = (symtab + ((Elf_Symndx *) D_PTR (map, l_info[DT_HASH]))[1]);
+  else
+  /* There is no direct way to determine the number of symbols in the
+     dynamic symbol table and no hash table is present.  The ELF
+     binary is ill-formed but what shall we do?  Use the beginning of
+     the string table which generally follows the symbol table.  */
+    symtabend = (const ElfW(Sym) *) strtab;
+
+  len = (((char *) symtabend - (char *) symtab)
 	 / map->l_info[DT_SYMENT]->d_un.d_val);
-  size = ((len * sizeof (fptr_table[0]) + GLRO(dl_pagesize) - 1)
-	  & -GLRO(dl_pagesize));
-  /* XXX We don't support here in the moment systems without MAP_ANON.
-     There probably are none for IA-64.  In case this is proven wrong
-     we will have to open /dev/null here and use the file descriptor
-     instead of the hard-coded -1.  */
+  size = ALIGN_UP (len * sizeof (fptr_table[0]), GLRO(dl_pagesize));
+
+  /* We don't support systems without MAP_ANON.  We avoid using malloc
+     because this might get called before malloc is setup.  */
   fptr_table = __mmap (NULL, size,
 		       PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,
 		       -1, 0);