* [PATCH] Find .note.ABI-tag notes even when multiple notes are in one PT_NOTE segment
@ 2007-06-29 9:07 Jakub Jelinek
0 siblings, 0 replies; only message in thread
From: Jakub Jelinek @ 2007-06-29 9:07 UTC (permalink / raw)
To: Ulrich Drepper, Roland McGrath; +Cc: Glibc hackers
Hi!
All other places in glibc that handle notes already handle multiple
notes in PT_NOTE segment (which ELF gABI allows), just .note.ABI-tag
code in ld.so and ldconfig insisted it is the only note present.
2007-06-29 Jakub Jelinek <jakub@redhat.com>
* elf/dl-load.c (open_verify): Find .note.ABI-tag notes even
in PT_NOTE segments with multiple notes.
* elf/readelflib.c (process_elf_file): Likewise.
--- libc/elf/dl-load.c.jj 2007-06-29 10:19:54.000000000 +0200
+++ libc/elf/dl-load.c 2007-06-29 10:45:28.000000000 +0200
@@ -1634,7 +1634,7 @@ open_verify (const char *name, struct fi
{
ElfW(Ehdr) *ehdr;
ElfW(Phdr) *phdr, *ph;
- ElfW(Word) *abi_note, abi_note_buf[8];
+ ElfW(Word) *abi_note;
unsigned int osversion;
size_t maplength;
@@ -1751,20 +1751,37 @@ open_verify (const char *name, struct fi
/* Check .note.ABI-tag if present. */
for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
- if (ph->p_type == PT_NOTE && ph->p_filesz == 32 && ph->p_align >= 4)
+ if (ph->p_type == PT_NOTE && ph->p_filesz >= 32 && ph->p_align >= 4)
{
- if (ph->p_offset + 32 <= (size_t) fbp->len)
+ ElfW(Addr) size = ph->p_filesz;
+
+ if (ph->p_offset + size <= (size_t) fbp->len)
abi_note = (void *) (fbp->buf + ph->p_offset);
else
{
+ abi_note = alloca (size);
__lseek (fd, ph->p_offset, SEEK_SET);
- if (__libc_read (fd, (void *) abi_note_buf, 32) != 32)
+ if (__libc_read (fd, (void *) abi_note, size) != size)
goto read_error;
+ }
- abi_note = abi_note_buf;
+ while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
+ {
+#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
+ ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
+ + ROUND (abi_note[0])
+ + ROUND (abi_note[1]);
+
+ if (size - 32 < note_size)
+ {
+ size = 0;
+ break;
+ }
+ size -= note_size;
+ abi_note = (void *) abi_note + note_size;
}
- if (memcmp (abi_note, &expected_note, sizeof (expected_note)))
+ if (size == 0)
continue;
osversion = (abi_note[5] & 0xff) * 65536
--- libc/elf/readelflib.c.jj 2005-12-14 11:05:56.000000000 +0100
+++ libc/elf/readelflib.c 2007-06-29 10:46:00.000000000 +0200
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2001, 2002, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 1999 and
Jakub Jelinek <jakub@redhat.com>, 1999.
@@ -127,16 +127,37 @@ process_elf_file (const char *file_name,
break;
case PT_NOTE:
- if (!*osversion && segment->p_filesz == 32 && segment->p_align >= 4)
+ if (!*osversion && segment->p_filesz >= 32 && segment->p_align >= 4)
{
ElfW(Word) *abi_note = (ElfW(Word) *) (file_contents
+ segment->p_offset);
- if (abi_note [0] == 4 && abi_note [1] == 16 && abi_note [2] == 1
- && memcmp (abi_note + 3, "GNU", 4) == 0)
- *osversion = (abi_note [4] << 24) |
- ((abi_note [5] & 0xff) << 16) |
- ((abi_note [6] & 0xff) << 8) |
- (abi_note [7] & 0xff);
+ ElfW(Addr) size = segment->p_filesz;
+
+ while (abi_note [0] != 4 || abi_note [1] != 16
+ || abi_note [2] != 1
+ || memcmp (abi_note + 3, "GNU", 4) != 0)
+ {
+#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
+ ElfW(Addr) note_size = 3 * sizeof (ElfW(Word))
+ + ROUND (abi_note[0])
+ + ROUND (abi_note[1]);
+
+ if (size - 32 < note_size || note_size == 0)
+ {
+ size = 0;
+ break;
+ }
+ size -= note_size;
+ abi_note = (void *) abi_note + note_size;
+ }
+
+ if (size == 0)
+ break;
+
+ *osversion = (abi_note [4] << 24) |
+ ((abi_note [5] & 0xff) << 16) |
+ ((abi_note [6] & 0xff) << 8) |
+ (abi_note [7] & 0xff);
}
break;
Jakub
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