Allocate the first .plt entry space only if needed

Commit dd7e64d45b may optimize out
i386/x86-64 JUMP_SLOT relocation.  If there is no JUMP_SLOT relocation
left, we don't need to the first .plt entry.  This patch allocates
space for the first .plt entry only if we also reserve space for a PLT
slot for JUMP_SLOT relocation.

bfd/

	* elf32-i386.c (elf_i386_allocate_dynrelocs): Allocate space
	for the first .plt entry only if needed.
	* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise.

ld/testsuite/

	* ld-i386/i386.exp: Run pltgot-1 for Linux targets.
	* ld-x86-64/x86-64.exp: Likewise.
	* ld-i386/pltgot-1.d: New file.
	* ld-i386/pltgot-1.s: Likewise.
	* ld-x86-64/pltgot-1.d: Likewise.
	* ld-x86-64/pltgot-1.s: Likewise.
This commit is contained in:
H.J. Lu 2015-05-12 13:11:48 -07:00
parent 98624574ea
commit a3747075ae
10 changed files with 63 additions and 11 deletions

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@ -1,3 +1,9 @@
2015-05-12 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (elf_i386_allocate_dynrelocs): Allocate space
for the first .plt entry only if needed.
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise.
2015-05-11 H.J. Lu <hongjiu.lu@intel.com>
* Makefile.am (ALL_MACHINES): Add cpu-iamcu.lo.

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@ -2338,15 +2338,16 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
asection *s = htab->elf.splt;
asection *got_s = htab->plt_got;
/* If this is the first .plt entry, make room for the special
first entry. */
if (s->size == 0)
s->size = plt_entry_size;
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
h->plt.offset = s->size;
{
/* If this is the first .plt entry, make room for the
special first entry. */
if (s->size == 0)
s->size = plt_entry_size;
h->plt.offset = s->size;
}
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this

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@ -2558,15 +2558,14 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
asection *bnd_s = htab->plt_bnd;
asection *got_s = htab->plt_got;
/* If this is the first .plt entry, make room for the special
first entry. */
if (s->size == 0)
s->size = plt_entry_size;
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
{
/* If this is the first .plt entry, make room for the
special first entry. */
if (s->size == 0)
s->size = plt_entry_size;
h->plt.offset = s->size;
if (bnd_s)
eh->plt_bnd.offset = bnd_s->size;

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@ -1,3 +1,12 @@
2015-05-12 H.J. Lu <hongjiu.lu@intel.com>
* ld-i386/i386.exp: Run pltgot-1 for Linux targets.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pltgot-1.d: New file.
* ld-i386/pltgot-1.s: Likewise.
* ld-x86-64/pltgot-1.d: Likewise.
* ld-x86-64/pltgot-1.s: Likewise.
2015-05-11 H.J. Lu <hongjiu.lu@intel.com>
* ld-i386/i386.exp (iamcu_tests): Run iamcu-4.

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@ -493,3 +493,11 @@ if { [isnative]
] \
]
}
if { !([istarget "i?86-*-linux*"]
|| [istarget "x86_64-*-linux*"]) } {
return
}
# Linux only tests
run_dump_test "pltgot-1"

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@ -0,0 +1,8 @@
#ld: -shared -melf_i386
#readelf: -S --wide
#as: --32
#failif
#...
+\[ [0-9]+\] \.plt +PROGBITS +.*
#...

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@ -0,0 +1,6 @@
.text
.globl plt
.type plt, @function
plt:
call *puts@GOT(%ebx)
jmp puts@PLT

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@ -0,0 +1,8 @@
#ld: -shared -melf_x86_64
#readelf: -S --wide
#as: --64
#failif
#...
+\[ [0-9]+\] \.plt +PROGBITS +.*
#...

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@ -0,0 +1,6 @@
.text
.globl plt
.type plt, @function
plt:
call *puts@GOTPCREL(%rip)
jmp puts@PLT

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@ -549,3 +549,4 @@ if { ![istarget "x86_64-*-linux*"]} {
# Linux only tests
run_dump_test "pr17618"
run_dump_test "pltgot-1"