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Clean up R_ARM_PC24 handling.

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This commit is contained in:
Roland McGrath 2012-10-05 09:39:23 -07:00
parent 53cea63e99
commit fb228a2d94
2 changed files with 57 additions and 69 deletions
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6
ports/ChangeLog.arm
View file

@ -1,3 +1,9 @@
2012-10-05 Roland McGrath <roland@hack.frob.com>
* sysdeps/arm/dl-machine.h (fix_bad_pc24): Rewritten, replaced with ...
(relocate_pc24): ... this new function.
(elf_machine_rel, elf_machine_rela): Update callers.
2012-10-02 Siddhesh Poyarekar <siddhesh@redhat.com>
* sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h: Fix clone

120
ports/sysdeps/arm/dl-machine.h
View file

@ -302,36 +302,56 @@ elf_machine_plt_value (struct link_map *map, const Elf32_Rel *reloc,
#define ARCH_LA_PLTEXIT arm_gnu_pltexit
#ifdef RESOLVE_MAP
/* Deal with an out-of-range PC24 reloc. */
auto Elf32_Addr
fix_bad_pc24 (Elf32_Addr *const reloc_addr, Elf32_Addr value)
/* Handle a PC24 reloc, including the out-of-range case. */
auto void
relocate_pc24 (struct link_map *map, Elf32_Addr value,
Elf32_Addr *const reloc_addr, Elf32_Sword addend)
{
static void *fix_page;
static unsigned int fix_offset;
static size_t pagesize;
Elf32_Word *fix_address;
Elf32_Addr new_value;
if (! fix_page)
/* Set NEW_VALUE based on V, and return true iff it overflows 24 bits. */
inline bool set_new_value (Elf32_Addr v)
{
new_value = v + addend - (Elf32_Addr) reloc_addr;
Elf32_Addr topbits = new_value & 0xfe000000;
return topbits != 0xfe000000 && topbits != 0x00000000;
}
if (set_new_value (value))
{
if (! pagesize)
pagesize = getpagesize ();
fix_page = mmap (NULL, pagesize, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (! fix_page)
assert (! "could not map page for fixup");
fix_offset = 0;
/* The PC-relative address doesn't fit in 24 bits! */
static void *fix_page;
static size_t fix_offset;
if (fix_page == NULL)
{
void *new_page = __mmap (NULL, GLRO(dl_pagesize),
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (new_page == MAP_FAILED)
_dl_signal_error (0, map->l_name, NULL,
"could not map page for fixup");
fix_page = new_page;
assert (fix_offset == 0);
}
Elf32_Word *fix_address = fix_page + fix_offset;
fix_address[0] = 0xe51ff004; /* ldr pc, [pc, #-4] */
fix_address[1] = value;
fix_offset += sizeof fix_address[0] * 2;
if (fix_offset >= GLRO(dl_pagesize))
{
fix_page = NULL;
fix_offset = 0;
}
if (set_new_value ((Elf32_Addr) fix_address))
_dl_signal_error (0, map->l_name, NULL,
"R_ARM_PC24 relocation out of range");
}
fix_address = (Elf32_Word *)(fix_page + fix_offset);
fix_address[0] = 0xe51ff004; /* ldr pc, [pc, #-4] */
fix_address[1] = value;
fix_offset += 8;
if (fix_offset >= pagesize)
fix_page = NULL;
return (Elf32_Addr)fix_address;
*reloc_addr = (*reloc_addr & 0xff000000) | ((new_value >> 2) & 0x00ffffff);
}
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
@ -473,30 +493,11 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc,
}
break;
case R_ARM_PC24:
{
Elf32_Sword addend;
Elf32_Addr newvalue, topbits;
addend = *reloc_addr & 0x00ffffff;
if (addend & 0x00800000) addend |= 0xff000000;
newvalue = value - (Elf32_Addr)reloc_addr + (addend << 2);
topbits = newvalue & 0xfe000000;
if (topbits != 0xfe000000 && topbits != 0x00000000)
{
newvalue = fix_bad_pc24(reloc_addr, value)
- (Elf32_Addr)reloc_addr + (addend << 2);
topbits = newvalue & 0xfe000000;
if (topbits != 0xfe000000 && topbits != 0x00000000)
{
_dl_signal_error (0, map->l_name, NULL,
"R_ARM_PC24 relocation out of range");
}
}
newvalue >>= 2;
value = (*reloc_addr & 0xff000000) | (newvalue & 0x00ffffff);
*reloc_addr = value;
}
relocate_pc24 (map, value, reloc_addr,
/* Sign-extend the 24-bit addend in the
instruction (which counts instructions), and
then shift it up two so as to count bytes. */
(((Elf32_Sword) *reloc_addr << 8) >> 8) << 2);
break;
#if !defined RTLD_BOOTSTRAP
case R_ARM_TLS_DTPMOD32:
@ -589,26 +590,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
*reloc_addr = value + reloc->r_addend;
break;
case R_ARM_PC24:
{
Elf32_Addr newvalue, topbits;
newvalue = value + reloc->r_addend - (Elf32_Addr)reloc_addr;
topbits = newvalue & 0xfe000000;
if (topbits != 0xfe000000 && topbits != 0x00000000)
{
newvalue = fix_bad_pc24(reloc_addr, value)
- (Elf32_Addr)reloc_addr + (reloc->r_addend << 2);
topbits = newvalue & 0xfe000000;
if (topbits != 0xfe000000 && topbits != 0x00000000)
{
_dl_signal_error (0, map->l_name, NULL,
"R_ARM_PC24 relocation out of range");
}
}
newvalue >>= 2;
value = (*reloc_addr & 0xff000000) | (newvalue & 0x00ffffff);
*reloc_addr = value;
}
relocate_pc24 (map, value, reloc_addr, reloc->r_addend);
break;
#if !defined RTLD_BOOTSTRAP
case R_ARM_TLS_DTPMOD32: