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authorDaniel Jacobowitz <drow@false.org>2007-08-06 18:47:21 +0000
committerDaniel Jacobowitz <drow@false.org>2007-08-06 18:47:21 +0000
commitbd97cb95f84989bc1e3e771718098411c34338e2 (patch)
tree041fb5b71696f46b423fb8f9c3900129b609c15b
parentc981028a3fde8b53596ba2ab6dbf935e769e0c18 (diff)
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2007-08-06 Paul Brook <paul@codesourcery.com>
* elf32-arm.c (elf32_arm_link_hash_entry): Add plt_maybe_thumb_refcount. (elf32_arm_link_hash_newfunc): Set plt_maybe_thumb_refcount. (elf32_arm_copy_indirect_symbol): Ditto. (elf32_arm_adjust_dynamic_symbol): Ditto. (bfd_elf32_arm_process_before_allocation): Handle R_ARM_THM_JUMP24. (arm_add_to_rel): Ditto. (elf32_arm_final_link_relocate): Merge R_ARM_THM_JUMP24 with R_ARM_THM_CALL. Handle R_ARM_THM_JUMP19 against a PLT stub. (elf32_arm_gc_sweep_hook): Call check_use_blx. Update plt counts for R_ARM_THM_JUMP24 and R_ARM_THM_JUMP19. (elf32_arm_check_relocs): Update plt counts for R_ARM_THM_JUMP24 and R_ARM_THM_JUMP19. (allocate_dynrelocs): Use plt_maybe_thumb_refcount. (elf32_arm_finish_dynamic_symbol): Ditto. (elf32_arm_output_plt_map): Ditto.
-rw-r--r--bfd/ChangeLog19
-rw-r--r--bfd/elf32-arm.c158
2 files changed, 90 insertions, 87 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 50ce8c0..a410c9e 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,22 @@
+2007-08-06 Paul Brook <paul@codesourcery.com>
+
+ * elf32-arm.c (elf32_arm_link_hash_entry): Add
+ plt_maybe_thumb_refcount.
+ (elf32_arm_link_hash_newfunc): Set plt_maybe_thumb_refcount.
+ (elf32_arm_copy_indirect_symbol): Ditto.
+ (elf32_arm_adjust_dynamic_symbol): Ditto.
+ (bfd_elf32_arm_process_before_allocation): Handle R_ARM_THM_JUMP24.
+ (arm_add_to_rel): Ditto.
+ (elf32_arm_final_link_relocate): Merge R_ARM_THM_JUMP24 with
+ R_ARM_THM_CALL. Handle R_ARM_THM_JUMP19 against a PLT stub.
+ (elf32_arm_gc_sweep_hook): Call check_use_blx. Update plt counts
+ for R_ARM_THM_JUMP24 and R_ARM_THM_JUMP19.
+ (elf32_arm_check_relocs): Update plt counts for R_ARM_THM_JUMP24
+ and R_ARM_THM_JUMP19.
+ (allocate_dynrelocs): Use plt_maybe_thumb_refcount.
+ (elf32_arm_finish_dynamic_symbol): Ditto.
+ (elf32_arm_output_plt_map): Ditto.
+
2007-08-06 Daniel Jacobowitz <dan@codesourcery.com>
* elf.c (rewrite_elf_program_header): Handle sections not sorted
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index ed877f7..ef066d3 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -2129,6 +2129,10 @@ struct elf32_arm_link_hash_entry
so that we can emit the Thumb trampoline only if needed. */
bfd_signed_vma plt_thumb_refcount;
+ /* Some references from Thumb code may be eliminated by BL->BLX
+ conversion, so record them separately. */
+ bfd_signed_vma plt_maybe_thumb_refcount;
+
/* Since PLT entries have variable size if the Thumb prologue is
used, we need to record the index into .got.plt instead of
recomputing it from the PLT offset. */
@@ -2267,6 +2271,7 @@ elf32_arm_link_hash_newfunc (struct bfd_hash_entry * entry,
ret->relocs_copied = NULL;
ret->tls_type = GOT_UNKNOWN;
ret->plt_thumb_refcount = 0;
+ ret->plt_maybe_thumb_refcount = 0;
ret->plt_got_offset = -1;
ret->export_glue = NULL;
}
@@ -2422,6 +2427,8 @@ elf32_arm_copy_indirect_symbol (struct bfd_link_info *info,
/* Copy over PLT info. */
edir->plt_thumb_refcount += eind->plt_thumb_refcount;
eind->plt_thumb_refcount = 0;
+ edir->plt_maybe_thumb_refcount += eind->plt_maybe_thumb_refcount;
+ eind->plt_maybe_thumb_refcount = 0;
if (dir->got.refcount <= 0)
{
@@ -3162,7 +3169,8 @@ bfd_elf32_arm_process_before_allocation (bfd *abfd,
&& r_type != R_ARM_PLT32
&& r_type != R_ARM_CALL
&& r_type != R_ARM_JUMP24
- && r_type != R_ARM_THM_CALL)
+ && r_type != R_ARM_THM_CALL
+ && r_type != R_ARM_THM_JUMP24)
continue;
/* Get the section contents if we haven't done so already. */
@@ -3216,10 +3224,12 @@ bfd_elf32_arm_process_before_allocation (bfd *abfd,
break;
case R_ARM_THM_CALL:
+ case R_ARM_THM_JUMP24:
/* This one is a call from thumb code. We look
up the target of the call. If it is not a thumb
target, we insert glue. */
- if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC && !globals->use_blx
+ if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC
+ && !(globals->use_blx && r_type == R_ARM_THM_CALL)
&& h->root.type != bfd_link_hash_undefweak)
record_thumb_to_arm_glue (link_info, h);
break;
@@ -4996,6 +5006,7 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
case R_ARM_THM_XPC22:
case R_ARM_THM_CALL:
+ case R_ARM_THM_JUMP24:
/* Thumb BL (branch long instruction). */
{
bfd_vma relocation;
@@ -5059,7 +5070,7 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
&& (h == NULL || splt == NULL
|| h->plt.offset == (bfd_vma) -1))
{
- if (globals->use_blx)
+ if (globals->use_blx && r_type == R_ARM_THM_CALL)
{
/* Convert BL to BLX. */
lower_insn = (lower_insn & ~0x1000) | 0x0800;
@@ -5072,7 +5083,8 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
else
return bfd_reloc_dangerous;
}
- else if (sym_flags == STT_ARM_TFUNC && globals->use_blx)
+ else if (sym_flags == STT_ARM_TFUNC && globals->use_blx
+ && r_type == R_ARM_THM_CALL)
{
/* Make sure this is a BL. */
lower_insn |= 0x1800;
@@ -5085,7 +5097,7 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
value = (splt->output_section->vma
+ splt->output_offset
+ h->plt.offset);
- if (globals->use_blx)
+ if (globals->use_blx && r_type == R_ARM_THM_CALL)
{
/* If the Thumb BLX instruction is available, convert the
BL to a BLX instruction to call the ARM-mode PLT entry. */
@@ -5125,7 +5137,7 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
overflow = TRUE;
- if ((lower_insn & 0x1800) == 0x0800)
+ if ((lower_insn & 0x5000) == 0x4000)
/* For a BLX instruction, make sure that the relocation is rounded up
to a word boundary. This follows the semantics of the instruction
which specifies that bit 1 of the target address will come from bit
@@ -5152,79 +5164,6 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
}
break;
- case R_ARM_THM_JUMP24:
- /* Thumb32 unconditional branch instruction. */
- {
- bfd_vma relocation;
- bfd_boolean overflow = FALSE;
- bfd_vma upper_insn = bfd_get_16 (input_bfd, hit_data);
- bfd_vma lower_insn = bfd_get_16 (input_bfd, hit_data + 2);
- bfd_signed_vma reloc_signed_max = ((1 << (howto->bitsize - 1)) - 1) >> howto->rightshift;
- bfd_signed_vma reloc_signed_min = ~ reloc_signed_max;
- bfd_vma check;
- bfd_signed_vma signed_check;
-
- /* Need to refetch the addend, reconstruct the top three bits, and glue the
- two pieces together. */
- if (globals->use_rel)
- {
- bfd_vma S = (upper_insn & 0x0400) >> 10;
- bfd_vma hi = (upper_insn & 0x03ff);
- bfd_vma I1 = (lower_insn & 0x2000) >> 13;
- bfd_vma I2 = (lower_insn & 0x0800) >> 11;
- bfd_vma lo = (lower_insn & 0x07ff);
-
- I1 = !(I1 ^ S);
- I2 = !(I2 ^ S);
- S = !S;
-
- signed_addend = (S << 24) | (I1 << 23) | (I2 << 22) | (hi << 12) | (lo << 1);
- signed_addend -= (1 << 24); /* Sign extend. */
- }
-
- /* ??? Should handle interworking? GCC might someday try to
- use this for tail calls. */
-
- relocation = value + signed_addend;
- relocation -= (input_section->output_section->vma
- + input_section->output_offset
- + rel->r_offset);
-
- check = relocation >> howto->rightshift;
-
- /* If this is a signed value, the rightshift just dropped
- leading 1 bits (assuming twos complement). */
- if ((bfd_signed_vma) relocation >= 0)
- signed_check = check;
- else
- signed_check = check | ~((bfd_vma) -1 >> howto->rightshift);
-
- /* Assumes two's complement. */
- if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
- overflow = TRUE;
-
- /* Put RELOCATION back into the insn. */
- {
- bfd_vma S = (relocation & 0x01000000) >> 24;
- bfd_vma I1 = (relocation & 0x00800000) >> 23;
- bfd_vma I2 = (relocation & 0x00400000) >> 22;
- bfd_vma hi = (relocation & 0x003ff000) >> 12;
- bfd_vma lo = (relocation & 0x00000ffe) >> 1;
-
- I1 = !(I1 ^ S);
- I2 = !(I2 ^ S);
-
- upper_insn = (upper_insn & (bfd_vma) 0xf800) | (S << 10) | hi;
- lower_insn = (lower_insn & (bfd_vma) 0xd000) | (I1 << 13) | (I2 << 11) | lo;
- }
-
- /* Put the relocated value back in the object file: */
- bfd_put_16 (input_bfd, upper_insn, hit_data);
- bfd_put_16 (input_bfd, lower_insn, hit_data + 2);
-
- return (overflow ? bfd_reloc_overflow : bfd_reloc_ok);
- }
-
case R_ARM_THM_JUMP19:
/* Thumb32 conditional branch instruction. */
{
@@ -5255,6 +5194,17 @@ elf32_arm_final_link_relocate (reloc_howto_type * howto,
signed_addend = addend;
}
+ /* Handle calls via the PLT. */
+ if (h != NULL && splt != NULL && h->plt.offset != (bfd_vma) -1)
+ {
+ value = (splt->output_section->vma
+ + splt->output_offset
+ + h->plt.offset);
+ /* Target the Thumb stub before the ARM PLT entry. */
+ value -= PLT_THUMB_STUB_SIZE;
+ *unresolved_reloc_p = FALSE;
+ }
+
/* ??? Should handle interworking? GCC might someday try to
use this for tail calls. */
@@ -6266,7 +6216,8 @@ arm_add_to_rel (bfd * abfd,
{
bfd_signed_vma addend;
- if (howto->type == R_ARM_THM_CALL)
+ if (howto->type == R_ARM_THM_CALL
+ || howto->type == R_ARM_THM_JUMP24)
{
int upper_insn, lower_insn;
int upper, lower;
@@ -7400,6 +7351,8 @@ elf32_arm_gc_sweep_hook (bfd * abfd,
sym_hashes = elf_sym_hashes (abfd);
local_got_refcounts = elf_local_got_refcounts (abfd);
+ check_use_blx(globals);
+
relend = relocs + sec->reloc_count;
for (rel = relocs; rel < relend; rel++)
{
@@ -7450,6 +7403,8 @@ elf32_arm_gc_sweep_hook (bfd * abfd,
case R_ARM_JUMP24:
case R_ARM_PREL31:
case R_ARM_THM_CALL:
+ case R_ARM_THM_JUMP24:
+ case R_ARM_THM_JUMP19:
case R_ARM_MOVW_ABS_NC:
case R_ARM_MOVT_ABS:
case R_ARM_MOVW_PREL_NC:
@@ -7471,7 +7426,11 @@ elf32_arm_gc_sweep_hook (bfd * abfd,
if (h->plt.refcount > 0)
{
h->plt.refcount -= 1;
- if (ELF32_R_TYPE (rel->r_info) == R_ARM_THM_CALL)
+ if (r_type == R_ARM_THM_CALL)
+ eh->plt_maybe_thumb_refcount--;
+
+ if (r_type == R_ARM_THM_JUMP24
+ || r_type == R_ARM_THM_JUMP19)
eh->plt_thumb_refcount--;
}
@@ -7673,6 +7632,8 @@ elf32_arm_check_relocs (bfd *abfd, struct bfd_link_info *info,
case R_ARM_JUMP24:
case R_ARM_PREL31:
case R_ARM_THM_CALL:
+ case R_ARM_THM_JUMP24:
+ case R_ARM_THM_JUMP19:
case R_ARM_MOVW_ABS_NC:
case R_ARM_MOVT_ABS:
case R_ARM_MOVW_PREL_NC:
@@ -7708,7 +7669,15 @@ elf32_arm_check_relocs (bfd *abfd, struct bfd_link_info *info,
it, even if it's an ABS32 relocation. */
h->plt.refcount += 1;
+ /* It's too early to use htab->use_blx here, so we have to
+ record possible blx references separately from
+ relocs that definitely need a thumb stub. */
+
if (r_type == R_ARM_THM_CALL)
+ eh->plt_maybe_thumb_refcount += 1;
+
+ if (r_type == R_ARM_THM_JUMP24
+ || r_type == R_ARM_THM_JUMP19)
eh->plt_thumb_refcount += 1;
}
@@ -8059,6 +8028,7 @@ elf32_arm_adjust_dynamic_symbol (struct bfd_link_info * info,
linkage table, and we can just do a PC24 reloc instead. */
h->plt.offset = (bfd_vma) -1;
eh->plt_thumb_refcount = 0;
+ eh->plt_maybe_thumb_refcount = 0;
h->needs_plt = 0;
}
@@ -8073,6 +8043,7 @@ elf32_arm_adjust_dynamic_symbol (struct bfd_link_info * info,
the link may change h->type. So fix it now. */
h->plt.offset = (bfd_vma) -1;
eh->plt_thumb_refcount = 0;
+ eh->plt_maybe_thumb_refcount = 0;
}
/* If this is a weak symbol, and there is a real definition, the
@@ -8150,6 +8121,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
struct elf32_arm_link_hash_table *htab;
struct elf32_arm_link_hash_entry *eh;
struct elf32_arm_relocs_copied *p;
+ bfd_signed_vma thumb_refs;
eh = (struct elf32_arm_link_hash_entry *) h;
@@ -8191,7 +8163,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* If we will insert a Thumb trampoline before this PLT, leave room
for it. */
- if (!htab->use_blx && eh->plt_thumb_refcount > 0)
+ thumb_refs = eh->plt_thumb_refcount;
+ if (!htab->use_blx)
+ thumb_refs += eh->plt_maybe_thumb_refcount;
+
+ if (thumb_refs > 0)
{
h->plt.offset += PLT_THUMB_STUB_SIZE;
s->size += PLT_THUMB_STUB_SIZE;
@@ -8900,6 +8876,7 @@ elf32_arm_finish_dynamic_symbol (bfd * output_bfd, struct bfd_link_info * info,
}
else
{
+ bfd_signed_vma thumb_refs;
/* Calculate the displacement between the PLT slot and the
entry in the GOT. The eight-byte offset accounts for the
value produced by adding to pc in the first instruction
@@ -8908,7 +8885,11 @@ elf32_arm_finish_dynamic_symbol (bfd * output_bfd, struct bfd_link_info * info,
BFD_ASSERT ((got_displacement & 0xf0000000) == 0);
- if (!htab->use_blx && eh->plt_thumb_refcount > 0)
+ thumb_refs = eh->plt_thumb_refcount;
+ if (!htab->use_blx)
+ thumb_refs += eh->plt_maybe_thumb_refcount;
+
+ if (thumb_refs > 0)
{
put_thumb_insn (htab, output_bfd,
elf32_arm_plt_thumb_stub[0], ptr - 4);
@@ -9638,10 +9619,13 @@ elf32_arm_output_plt_map (struct elf_link_hash_entry *h, void *inf)
}
else
{
- bfd_boolean thumb_stub;
+ bfd_signed_vma thumb_refs;
+
+ thumb_refs = eh->plt_thumb_refcount;
+ if (!htab->use_blx)
+ thumb_refs += eh->plt_maybe_thumb_refcount;
- thumb_stub = eh->plt_thumb_refcount > 0 && !htab->use_blx;
- if (thumb_stub)
+ if (thumb_refs > 0)
{
if (!elf32_arm_ouput_plt_map_sym (osi, ARM_MAP_THUMB, addr - 4))
return FALSE;
@@ -9655,7 +9639,7 @@ elf32_arm_output_plt_map (struct elf_link_hash_entry *h, void *inf)
/* A three-word PLT with no Thumb thunk contains only Arm code,
so only need to output a mapping symbol for the first PLT entry and
entries with thumb thunks. */
- if (thumb_stub || addr == 20)
+ if (thumb_refs > 0 || addr == 20)
{
if (!elf32_arm_ouput_plt_map_sym (osi, ARM_MAP_ARM, addr))
return FALSE;