Patchwork allow to load android binary

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Submitter matthieu castet
Date March 2, 2011, 4:14 p.m.
Message ID <4D6E6CE5.5020805@free.fr>
Download mbox | patch
Permalink /patch/85097/
State New
Headers show

Comments

matthieu castet - March 2, 2011, 4:14 p.m.
Hi,

Android binary start with a weird elf program header : the first
one is of size 0 pointing to NULL addr.

Ignore LOAD program where MemSiz is 0.

Elf file type is EXEC (Executable file)
Entry point 0xb0001000
There are 5 program headers, starting at offset 52

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x0000d4 0x00000000 0xb0000000 0x00000 0x00000 R   0x1000
  LOAD           0x001000 0xb0001000 0xb0001000 0x073d4 0x073d4 R E 0x1000
  LOAD           0x009000 0xb0009000 0xb0009000 0x0068c 0x0969c RW  0x1000
  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RW  0
  EXIDX          0x00801c 0xb000801c 0xb000801c 0x003b8 0x003b8 R   0x4

 Section to Segment mapping:
  Segment Sections...
   00
   01     .text .rodata .ARM.extab .ARM.exidx
   02     .preinit_array .init_array .fini_array .ctors .data.rel.ro .got .data .bss
   03
   04     .ARM.exidx
vincent - March 28, 2012, 1:58 p.m.
matthieu castet <castet.matthieu <at> free.fr> writes:
> 
> Android binary start with a weird elf program header : the first
> one is of size 0 pointing to NULL addr.
> 
> Ignore LOAD program where MemSiz is 0.
> 
...
>
> Attachment (0001-allow-to-load-android-binary.patch): text/x-diff, 2172 bytes

This old patch (not mine) is required to run Android binaries with
QEMU user-mode but it was integrated yet, there was no reply indeed.
Do you want me to resend it with a more detailed description?
Peter Maydell - March 28, 2012, 2:15 p.m.
2012/3/28 C├ędric VINCENT <cedric.vincent@st.com>:
> matthieu castet <castet.matthieu <at> free.fr> writes:
>>
>> Android binary start with a weird elf program header : the first
>> one is of size 0 pointing to NULL addr.
>>
>> Ignore LOAD program where MemSiz is 0.

> This old patch (not mine) is required to run Android binaries with
> QEMU user-mode but it was integrated yet, there was no reply indeed.
> Do you want me to resend it with a more detailed description?

There was also this thread:
http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg02810.html
about a different patch attempting to fix the same issue. I'm not
sure which patch is better, haven't looked closely...

-- PMM

Patch

From 4d986b66e9ae04efeabde9ad73f60d3c2d6912f9 Mon Sep 17 00:00:00 2001
From: Matthieu CASTET <castet.matthieu@free.fr>
Date: Wed, 2 Mar 2011 17:04:39 +0100
Subject: [PATCH] allow to load android binary

Android binary start with a weird elf program header : the first
one is of size 0 pointing to NULL addr.

Ignore LOAD program where MemSiz is 0.

Elf file type is EXEC (Executable file)
Entry point 0xb0001000
There are 5 program headers, starting at offset 52

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x0000d4 0x00000000 0xb0000000 0x00000 0x00000 R   0x1000
  LOAD           0x001000 0xb0001000 0xb0001000 0x073d4 0x073d4 R E 0x1000
  LOAD           0x009000 0xb0009000 0xb0009000 0x0068c 0x0969c RW  0x1000
  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RW  0
  EXIDX          0x00801c 0xb000801c 0xb000801c 0x003b8 0x003b8 R   0x4

 Section to Segment mapping:
  Segment Sections...
   00
   01     .text .rodata .ARM.extab .ARM.exidx
   02     .preinit_array .init_array .fini_array .ctors .data.rel.ro .got .data .bss
   03
   04     .ARM.exidx
---
 linux-user/elfload.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 33d776d..284f3be 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1201,7 +1201,7 @@  static void load_elf_image(const char *image_name, int image_fd,
        amount of memory to handle that.  */
     loaddr = -1, hiaddr = 0;
     for (i = 0; i < ehdr->e_phnum; ++i) {
-        if (phdr[i].p_type == PT_LOAD) {
+        if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz) {
             abi_ulong a = phdr[i].p_vaddr;
             if (a < loaddr) {
                 loaddr = a;
@@ -1301,7 +1301,7 @@  static void load_elf_image(const char *image_name, int image_fd,
 
     for (i = 0; i < ehdr->e_phnum; i++) {
         struct elf_phdr *eppnt = phdr + i;
-        if (eppnt->p_type == PT_LOAD) {
+        if (eppnt->p_type == PT_LOAD && eppnt->p_memsz) {
             abi_ulong vaddr, vaddr_po, vaddr_ps, vaddr_ef, vaddr_em;
             int elf_prot = 0;
 
-- 
1.7.4.1