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(elf_machine_runtime_setup): If we are

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not looking at the new thread-safe .plt, don't be lazy about relocs.
(_dl_runtime_resolve): Fix up arithmetic for new .plt layout.
(elf_alpha_fix_plt): Insert wmb as appropriate to ensure safety.
This commit is contained in:
Ulrich Drepper
1997-05-24 02:10:36 +00:00
parent c751295fb8
commit 76a2c2cb6a
1 changed files with 25 additions and 9 deletions
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34
sysdeps/alpha/dl-machine.h
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@@ -86,7 +86,7 @@ elf_machine_load_address (void)
/* Set up the loaded object described by L so its unrelocated PLT /* Set up the loaded object described by L so its unrelocated PLT
entries will jump to the on-demand fixup code in dl-runtime.c. */ entries will jump to the on-demand fixup code in dl-runtime.c. */
static inline void static inline int
elf_machine_runtime_setup (struct link_map *l, int lazy) elf_machine_runtime_setup (struct link_map *l, int lazy)
{ {
Elf64_Addr plt; Elf64_Addr plt;
@@ -104,7 +104,13 @@ elf_machine_runtime_setup (struct link_map *l, int lazy)
/* Identify this shared object */ /* Identify this shared object */
*(Elf64_Addr *)(plt + 24) = (Elf64_Addr) l; *(Elf64_Addr *)(plt + 24) = (Elf64_Addr) l;
/* If the first instruction of the plt entry is not
"br $28, plt0", we cannot do lazy relocation. */
lazy = (*(unsigned *)(plt + 32) == 0xc39ffff7);
} }
return lazy;
} }
/* This code is used in dl-runtime.c to call the `fixup' function /* This code is used in dl-runtime.c to call the `fixup' function
@@ -145,9 +151,11 @@ _dl_runtime_resolve:
.prologue 1 .prologue 1
/* Set up the arguments for _dl_runtime_resolve. */ /* Set up the arguments for _dl_runtime_resolve. */
/* $16 = link_map out of plt0 */ /* $16 = link_map out of plt0 */
/* $17 = offset of reloc entry = ($28 - $27 - 20) /12 * 24 */
subq $28, $27, $17
ldq $16, 8($27) ldq $16, 8($27)
/* $17 = offset of reloc entry */ subq $17, 20, $17
mov $28, $17 addq $17, $17, $17
/* Do the fixup */ /* Do the fixup */
bsr $26, fixup..ng bsr $26, fixup..ng
/* Move the destination address into position. */ /* Move the destination address into position. */
@@ -290,14 +298,18 @@ elf_alpha_fix_plt(struct link_map *l,
lo = (short)hi; lo = (short)hi;
hi = (hi - lo) >> 16; hi = (hi - lo) >> 16;
/* Emit "ldah $27,H($27)" */
plte[0] = 0x277b0000 | (hi & 0xffff);
/* Emit "lda $27,L($27)" */ /* Emit "lda $27,L($27)" */
plte[1] = 0x237b0000 | (lo & 0xffff); plte[1] = 0x237b0000 | (lo & 0xffff);
/* Emit "br $31,function" */ /* Emit "br $31,function" */
plte[2] = 0xc3e00000 | (edisp & 0x1fffff); plte[2] = 0xc3e00000 | (edisp & 0x1fffff);
/* Think about thread-safety -- the previous instructions must be
committed to memory before the first is overwritten. */
__asm__ __volatile__("wmb" : : : "memory");
/* Emit "ldah $27,H($27)" */
plte[0] = 0x277b0000 | (hi & 0xffff);
} }
else else
{ {
@@ -310,14 +322,18 @@ elf_alpha_fix_plt(struct link_map *l,
lo = (short)hi; lo = (short)hi;
hi = (hi - lo) >> 16; hi = (hi - lo) >> 16;
/* Emit "ldah $27,H($27)" */
plte[0] = 0x277b0000 | (hi & 0xffff);
/* Emit "ldq $27,L($27)" */ /* Emit "ldq $27,L($27)" */
plte[1] = 0xa77b0000 | (lo & 0xffff); plte[1] = 0xa77b0000 | (lo & 0xffff);
/* Emit "jmp $31,($27)" */ /* Emit "jmp $31,($27)" */
plte[2] = 0x6bfb0000; plte[2] = 0x6bfb0000;
/* Think about thread-safety -- the previous instructions must be
committed to memory before the first is overwritten. */
__asm__ __volatile__("wmb" : : : "memory");
/* Emit "ldah $27,H($27)" */
plte[0] = 0x277b0000 | (hi & 0xffff);
} }
/* At this point, if we've been doing runtime resolution, Icache is dirty. /* At this point, if we've been doing runtime resolution, Icache is dirty.