[PATCH] BFD: Deal with relocations which are 3 bytes in size
Alan Modra
amodra@gmail.com
Sat Aug 11 04:16:00 GMT 2018
On Thu, Aug 09, 2018 at 06:46:51PM +0200, John Darrington wrote:
> bfd/
> * reloc.c (_bfd_relocate_contents): Deal with case 3.
> * reloc.c (_bfd_clear_contents): ditto
> * reloc.c ( bfd_perform_relocation): ditto
> * reloc.c ( bfd_install_relocation): ditto
Applied.
I'm also applying this followup, which would have made your patch
simpler.
----
Factor out common relocation processing
This patch factors out some code common to both bfd_perform_relocation
and bfd_install_relocation, in the process fixing the omission of
"case -1" in bfd_install_relocation.
* reloc.c (bfd_get_reloc_size): Sort switch.
(read_reloc, write_reloc, apply_reloc): New functions.
(bfd_perform_relocation, bfd_install_relocation): Use apply_reloc.
(_bfd_relocate_contents): Use read_reloc and write_reloc.
(_bfd_clear_contents): Likewise.
diff --git a/bfd/reloc.c b/bfd/reloc.c
index 775a4403ef..aaf3a801fd 100644
--- a/bfd/reloc.c
+++ b/bfd/reloc.c
@@ -431,15 +431,15 @@ bfd_get_reloc_size (reloc_howto_type *howto)
{
switch (howto->size)
{
- case 5: return 3;
case 0: return 1;
- case 1: return 2;
- case 2: return 4;
+ case 1:
+ case -1: return 2;
+ case 2:
+ case -2: return 4;
case 3: return 0;
case 4: return 8;
+ case 5: return 3;
case 8: return 16;
- case -1: return 2;
- case -2: return 4;
default: abort ();
}
}
@@ -574,6 +574,100 @@ bfd_reloc_offset_in_range (reloc_howto_type *howto,
return octet <= octet_end && octet + reloc_size <= octet_end;
}
+/* Read and return the section contents at DATA converted to a host
+ integer (bfd_vma). The number of bytes read is given by the HOWTO. */
+
+static bfd_vma
+read_reloc (bfd *abfd, bfd_byte *data, reloc_howto_type *howto)
+{
+ switch (howto->size)
+ {
+ case 0:
+ return bfd_get_8 (abfd, data);
+
+ case 1:
+ case -1:
+ return bfd_get_16 (abfd, data);
+
+ case 2:
+ case -2:
+ return bfd_get_32 (abfd, data);
+
+ case 3:
+ break;
+
+#ifdef BFD64
+ case 4:
+ return bfd_get_64 (abfd, data);
+#endif
+
+ case 5:
+ return bfd_get_24 (abfd, data);
+
+ default:
+ abort ();
+ }
+ return 0;
+}
+
+/* Convert VAL to target format and write to DATA. The number of
+ bytes written is given by the HOWTO. */
+
+static void
+write_reloc (bfd *abfd, bfd_vma val, bfd_byte *data, reloc_howto_type *howto)
+{
+ switch (howto->size)
+ {
+ case 0:
+ bfd_put_8 (abfd, val, data);
+ break;
+
+ case 1:
+ case -1:
+ bfd_put_16 (abfd, val, data);
+ break;
+
+ case 2:
+ case -2:
+ bfd_put_32 (abfd, val, data);
+ break;
+
+ case 3:
+ break;
+
+#ifdef BFD64
+ case 4:
+ bfd_put_64 (abfd, val, data);
+ break;
+#endif
+
+ case 5:
+ bfd_put_24 (abfd, val, data);
+ break;
+
+ default:
+ abort ();
+ }
+}
+
+/* Apply RELOCATION value to target bytes at DATA, according to
+ HOWTO. */
+
+static void
+apply_reloc (bfd *abfd, bfd_byte *data, reloc_howto_type *howto,
+ bfd_vma relocation)
+{
+ bfd_vma val = read_reloc (abfd, data, howto);
+
+ if (howto->size < 0)
+ relocation = -relocation;
+
+ val = ((val & ~howto->dst_mask)
+ | (((val & howto->src_mask) + relocation) & howto->dst_mask));
+
+ write_reloc (abfd, val, data, howto);
+}
+
/*
FUNCTION
bfd_perform_relocation
@@ -913,78 +1007,8 @@ space consuming. For each target:
= R R R R R R R R R R put into bfd_put<size>
*/
-#define DOIT(x) \
- x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
-
- switch (howto->size)
- {
- case 5:
- {
- long x = bfd_get_24 (abfd, (bfd_byte *) data + octets);
- DOIT (x);
- bfd_put_24 (abfd, (bfd_vma) x, (unsigned char *) data + octets);
- }
- break;
-
- case 0:
- {
- char x = bfd_get_8 (abfd, (char *) data + octets);
- DOIT (x);
- bfd_put_8 (abfd, x, (unsigned char *) data + octets);
- }
- break;
-
- case 1:
- {
- short x = bfd_get_16 (abfd, (bfd_byte *) data + octets);
- DOIT (x);
- bfd_put_16 (abfd, (bfd_vma) x, (unsigned char *) data + octets);
- }
- break;
- case 2:
- {
- long x = bfd_get_32 (abfd, (bfd_byte *) data + octets);
- DOIT (x);
- bfd_put_32 (abfd, (bfd_vma) x, (bfd_byte *) data + octets);
- }
- break;
- case -2:
- {
- long x = bfd_get_32 (abfd, (bfd_byte *) data + octets);
- relocation = -relocation;
- DOIT (x);
- bfd_put_32 (abfd, (bfd_vma) x, (bfd_byte *) data + octets);
- }
- break;
-
- case -1:
- {
- long x = bfd_get_16 (abfd, (bfd_byte *) data + octets);
- relocation = -relocation;
- DOIT (x);
- bfd_put_16 (abfd, (bfd_vma) x, (bfd_byte *) data + octets);
- }
- break;
-
- case 3:
- /* Do nothing */
- break;
-
- case 4:
-#ifdef BFD64
- {
- bfd_vma x = bfd_get_64 (abfd, (bfd_byte *) data + octets);
- DOIT (x);
- bfd_put_64 (abfd, x, (bfd_byte *) data + octets);
- }
-#else
- abort ();
-#endif
- break;
- default:
- return bfd_reloc_other;
- }
-
+ data = (bfd_byte *) data + octets;
+ apply_reloc (abfd, data, howto, relocation);
return flag;
}
@@ -1309,66 +1333,8 @@ space consuming. For each target:
= R R R R R R R R R R put into bfd_put<size>
*/
-#define DOIT(x) \
- x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
-
data = (bfd_byte *) data_start + (octets - data_start_offset);
-
- switch (howto->size)
- {
- case 0:
- {
- char x = bfd_get_8 (abfd, data);
- DOIT (x);
- bfd_put_8 (abfd, x, data);
- }
- break;
-
- case 1:
- {
- short x = bfd_get_16 (abfd, data);
- DOIT (x);
- bfd_put_16 (abfd, (bfd_vma) x, data);
- }
- break;
- case 2:
- {
- long x = bfd_get_32 (abfd, data);
- DOIT (x);
- bfd_put_32 (abfd, (bfd_vma) x, data);
- }
- break;
- case 5:
- {
- long x = bfd_get_24 (abfd, data);
- DOIT (x);
- bfd_put_24 (abfd, (bfd_vma) x, data);
- }
- break;
- case -2:
- {
- long x = bfd_get_32 (abfd, data);
- relocation = -relocation;
- DOIT (x);
- bfd_put_32 (abfd, (bfd_vma) x, data);
- }
- break;
-
- case 3:
- /* Do nothing */
- break;
-
- case 4:
- {
- bfd_vma x = bfd_get_64 (abfd, data);
- DOIT (x);
- bfd_put_64 (abfd, x, data);
- }
- break;
- default:
- return bfd_reloc_other;
- }
-
+ apply_reloc (abfd, data, howto, relocation);
return flag;
}
@@ -1447,8 +1413,7 @@ _bfd_relocate_contents (reloc_howto_type *howto,
bfd_vma relocation,
bfd_byte *location)
{
- int size;
- bfd_vma x = 0;
+ bfd_vma x;
bfd_reloc_status_type flag;
unsigned int rightshift = howto->rightshift;
unsigned int bitpos = howto->bitpos;
@@ -1459,33 +1424,7 @@ _bfd_relocate_contents (reloc_howto_type *howto,
relocation = -relocation;
/* Get the value we are going to relocate. */
- size = bfd_get_reloc_size (howto);
- switch (size)
- {
- default:
- abort ();
- case 0:
- return bfd_reloc_ok;
- case 1:
- x = bfd_get_8 (input_bfd, location);
- break;
- case 2:
- x = bfd_get_16 (input_bfd, location);
- break;
- case 3:
- x = bfd_get_24 (input_bfd, location);
- break;
- case 4:
- x = bfd_get_32 (input_bfd, location);
- break;
- case 8:
-#ifdef BFD64
- x = bfd_get_64 (input_bfd, location);
-#else
- abort ();
-#endif
- break;
- }
+ x = read_reloc (input_bfd, location, howto);
/* Check for overflow. FIXME: We may drop bits during the addition
which we don't check for. We must either check at every single
@@ -1591,31 +1530,7 @@ _bfd_relocate_contents (reloc_howto_type *howto,
| (((x & howto->src_mask) + relocation) & howto->dst_mask));
/* Put the relocated value back in the object file. */
- switch (size)
- {
- default:
- abort ();
- case 1:
- bfd_put_8 (input_bfd, x, location);
- break;
- case 2:
- bfd_put_16 (input_bfd, x, location);
- break;
- case 3:
- bfd_put_24 (input_bfd, x, location);
- break;
- case 4:
- bfd_put_32 (input_bfd, x, location);
- break;
- case 8:
-#ifdef BFD64
- bfd_put_64 (input_bfd, x, location);
-#else
- abort ();
-#endif
- break;
- }
-
+ write_reloc (input_bfd, x, location, howto);
return flag;
}
@@ -1630,37 +1545,10 @@ _bfd_clear_contents (reloc_howto_type *howto,
asection *input_section,
bfd_byte *location)
{
- int size;
- bfd_vma x = 0;
+ bfd_vma x;
/* Get the value we are going to relocate. */
- size = bfd_get_reloc_size (howto);
- switch (size)
- {
- default:
- abort ();
- case 0:
- return;
- case 1:
- x = bfd_get_8 (input_bfd, location);
- break;
- case 2:
- x = bfd_get_16 (input_bfd, location);
- break;
- case 3:
- x = bfd_get_24 (input_bfd, location);
- break;
- case 4:
- x = bfd_get_32 (input_bfd, location);
- break;
- case 8:
-#ifdef BFD64
- x = bfd_get_64 (input_bfd, location);
-#else
- abort ();
-#endif
- break;
- }
+ x = read_reloc (input_bfd, location, howto);
/* Zero out the unwanted bits of X. */
x &= ~howto->dst_mask;
@@ -1673,31 +1561,7 @@ _bfd_clear_contents (reloc_howto_type *howto,
x |= 1;
/* Put the relocated value back in the object file. */
- switch (size)
- {
- default:
- case 0:
- abort ();
- case 1:
- bfd_put_8 (input_bfd, x, location);
- break;
- case 2:
- bfd_put_16 (input_bfd, x, location);
- break;
- case 3:
- bfd_put_24 (input_bfd, x, location);
- break;
- case 4:
- bfd_put_32 (input_bfd, x, location);
- break;
- case 8:
-#ifdef BFD64
- bfd_put_64 (input_bfd, x, location);
-#else
- abort ();
-#endif
- break;
- }
+ write_reloc (input_bfd, x, location, howto);
}
/*
--
Alan Modra
Australia Development Lab, IBM
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