summaryrefslogtreecommitdiff
path: root/sysdeps/powerpc/dl-machine.h
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/dl-machine.h')
-rw-r--r--sysdeps/powerpc/dl-machine.h152
1 files changed, 79 insertions, 73 deletions
diff --git a/sysdeps/powerpc/dl-machine.h b/sysdeps/powerpc/dl-machine.h
index 917e4f7970..771b711a14 100644
--- a/sysdeps/powerpc/dl-machine.h
+++ b/sysdeps/powerpc/dl-machine.h
@@ -149,33 +149,34 @@ elf_machine_load_address (void)
#define elf_machine_relplt elf_machine_rela
/* This code is used in dl-runtime.c to call the `fixup' function
- and then redirect to the address it returns. It is called
- from code built in the PLT by elf_machine_runtime_setup. */
+ and then redirect to the address it returns. It is called
+ from code built in the PLT by elf_machine_runtime_setup. */
#define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
.section \".text\"
.align 2
.globl _dl_runtime_resolve
.type _dl_runtime_resolve,@function
_dl_runtime_resolve:
- # We need to save the registers used to pass parameters.
- # We build a stack frame to put them in.
+ # We need to save the registers used to pass parameters, and register 0,
+ # which is used by _mcount; the registers are saved in a stack frame.
stwu 1,-48(1)
- mflr 0
+ stw 0,12(1)
stw 3,16(1)
stw 4,20(1)
- stw 0,52(1)
+ # The code that calls this has put parameters for `fixup' in r12 and r11.
+ mr 3,12
stw 5,24(1)
- # We also need to save some of the condition register fields.
- mfcr 0
+ mr 4,11
stw 6,28(1)
+ mflr 0
+ # We also need to save some of the condition register fields.
stw 7,32(1)
+ stw 0,52(1)
stw 8,36(1)
+ mfcr 0
stw 9,40(1)
stw 10,44(1)
- stw 0,12(1)
- # The code that calls this has put parameters for `fixup' in r12 and r11.
- mr 3,12
- mr 4,11
+ stw 0,8(1)
bl fixup@local
# 'fixup' returns the address we want to branch to.
mtctr 3
@@ -184,20 +185,21 @@ _dl_runtime_resolve:
lwz 10,44(1)
lwz 9,40(1)
mtlr 0
- lwz 0,12(1)
lwz 8,36(1)
+ lwz 0,8(1)
lwz 7,32(1)
lwz 6,28(1)
mtcrf 0xFF,0
lwz 5,24(1)
lwz 4,20(1)
lwz 3,16(1)
+ lwz 0,12(1)
# ...unwind the stack frame, and jump to the PLT entry we updated.
addi 1,1,48
bctr
0:
.size _dl_runtime_resolve,0b-_dl_runtime_resolve
- # undo '.section text'.
+ # Undo '.section text'.
.previous
");
@@ -213,20 +215,20 @@ asm ("\
.type _start,@function
_start:
# We start with the following on the stack, from top:
- # argc (4 bytes)
- # arguments for program (terminated by NULL)
- # environment variables (terminated by NULL)
- # arguments for the program loader
+ # argc (4 bytes);
+ # arguments for program (terminated by NULL);
+ # environment variables (terminated by NULL);
+ # arguments for the program loader.
# FIXME: perhaps this should do the same trick as elf/start.c?
# Call _dl_start with one parameter pointing at argc
- mr 3,1
+ mr 3,1
# (we have to frob the stack pointer a bit to allow room for
# _dl_start to save the link register)
- li 4,0
+ li 4,0
addi 1,1,-16
- stw 4,0(1)
- bl _dl_start@local
+ stw 4,0(1)
+ bl _dl_start@local
# Now, we do our main work of calling initialisation procedures.
# The ELF ABI doesn't say anything about parameters for these,
@@ -234,70 +236,72 @@ _start:
# Changing these is strongly discouraged (not least because argc is
# passed by value!).
- # put our GOT pointer in r31
- bl _GLOBAL_OFFSET_TABLE_-4@local
+ # Put our GOT pointer in r31,
+ bl _GLOBAL_OFFSET_TABLE_-4@local
mflr 31
- # the address of _start in r30
- mr 30,3
- # &_dl_argc in 29, &_dl_argv in 27, and _dl_default_scope in 28
- lwz 28,_dl_default_scope@got(31)
- lwz 29,_dl_argc@got(31)
- lwz 27,_dl_argv@got(31)
+ # the address of _start in r30,
+ mr 30,3
+ # &_dl_argc in 29, &_dl_argv in 27, and _dl_default_scope in 28.
+ lwz 28,_dl_default_scope@got(31)
+ lwz 29,_dl_argc@got(31)
+ lwz 27,_dl_argv@got(31)
0:
- # call initfunc = _dl_init_next(_dl_default_scope[2])
- lwz 3,8(28)
- bl _dl_init_next@plt
- # if initfunc is NULL, we exit the loop
- mr. 0,3
- beq 1f
+ # Set initfunc = _dl_init_next(_dl_default_scope[2])
+ lwz 3,8(28)
+ bl _dl_init_next@plt
+ # If initfunc is NULL, we exit the loop; otherwise,
+ cmpwi 3,0
+ beq 1f
# call initfunc(_dl_argc, _dl_argv, _dl_argv+_dl_argc+1)
- mtlr 0
- lwz 3,0(29)
- lwz 4,0(27)
+ mtlr 3
+ lwz 3,0(29)
+ lwz 4,0(27)
slwi 5,3,2
- add 5,4,5
+ add 5,4,5
addi 5,5,4
blrl
# and loop.
- b 0b
+ b 0b
1:
# Now, to conform to the ELF ABI, we have to:
- # pass argv (actually _dl_argv) in r4
- lwz 4,0(27)
- # pass argc (actually _dl_argc) in r3
- lwz 3,0(29)
- # pass envp (actually _dl_argv+_dl_argc+1) in r5
+ # Pass argc (actually _dl_argc) in r3;
+ lwz 3,0(29)
+ # pass argv (actually _dl_argv) in r4;
+ lwz 4,0(27)
+ # pass envp (actually _dl_argv+_dl_argc+1) in r5;
slwi 5,3,2
- add 5,4,5
- addi 5,5,4
- # pass the auxilary vector in r6. This is passed just after _envp.
- addi 6,5,-4
+ add 6,4,5
+ addi 5,6,4
+ # pass the auxilary vector in r6. This is passed to us just after _envp.
2: lwzu 0,4(6)
- cmpwi 1,0,0
- bne 2b
+ cmpwi 0,0,0
+ bne 2b
addi 6,6,4
- # pass a termination function pointer (in this case _dl_fini) in r7
- lwz 7,_dl_fini@got(31)
- # now, call the start function in r30...
+ # Pass a termination function pointer (in this case _dl_fini) in r7.
+ lwz 7,_dl_fini@got(31)
+ # Now, call the start function in r30...
mtctr 30
- # pass the stack pointer in r1 (so far so good), pointing to a NULL value
- # (this lets our startup code distinguish between a program linked statically,
+ lwz 26,_dl_starting_up@got(31)
+ # Pass the stack pointer in r1 (so far so good), pointing to a NULL value.
+ # (This lets our startup code distinguish between a program linked statically,
# which linux will call with argc on top of the stack which will hopefully
# never be zero, and a dynamically linked program which will always have
# a NULL on the top of the stack).
# Take the opportunity to clear LR, so anyone who accidentally returns
- # from _start gets SEGV.
- li 0,0
- stw 0,0(1)
- mtlr 0
- # and also clear _dl_starting_up
- lwz 26,_dl_starting_up@got(31)
- stw 0,0(26)
- # go do it!
+ # from _start gets SEGV. Also clear the next few words of the stack.
+ li 31,0
+ stw 31,0(1)
+ mtlr 31
+ stw 31,4(1)
+ stw 31,8(1)
+ stw 31,12(1)
+ # Clear _dl_starting_up.
+ stw 31,0(26)
+ # Go do it!
bctr
0:
.size _start,0b-_start
- # undo '.section text'.
+ # Undo '.section text'.
.previous
");
@@ -346,7 +350,7 @@ static ElfW(Addr) _dl_preferred_address = 1
/* We require the address of the PLT entry returned from fixup, not
the first word of the PLT entry. */
-#define ELF_FIXUP_RETURN_VALUE(map, result) (&(result))
+#define ELF_FIXUP_RETURN_VALUE(map, result) ((Elf32_Addr) &(result))
/* Nonzero iff TYPE should not be allowed to resolve to one of
the main executable's symbols, as for a COPY reloc. */
@@ -396,7 +400,7 @@ elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
{
if (map->l_info[DT_JMPREL])
{
- int i;
+ Elf32_Word i;
/* Fill in the PLT. Its initial contents are directed to a
function earlier in the PLT which arranges for the dynamic
linker to be called back. */
@@ -516,10 +520,10 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
{
#ifndef RTLD_BOOTSTRAP
const Elf32_Sym *const refsym = sym;
+ extern char **_dl_argv;
#endif
Elf32_Word loadbase, finaladdr;
const int rinfo = ELF32_R_TYPE (reloc->r_info);
- extern char **_dl_argv;
if (rinfo == R_PPC_NONE)
return;
@@ -551,9 +555,9 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
+ reloc->r_addend);
}
- /* This is an if/else if chain because GCC 2.7.2.[012] turns case
- statements into non-PIC table lookups. When a later version
- comes out that fixes this, this should be changed. */
+ /* This is still an if/else if chain because GCC uses the GOT to find
+ the table for table-based switch statements, and we haven't set it
+ up yet. */
if (rinfo == R_PPC_UADDR32 ||
rinfo == R_PPC_GLOB_DAT ||
rinfo == R_PPC_ADDR32 ||
@@ -561,6 +565,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
{
*reloc_addr = finaladdr;
}
+#ifndef RTLD_BOOTSTRAP
else if (rinfo == R_PPC_ADDR16_LO)
{
*(Elf32_Half*) reloc_addr = finaladdr;
@@ -573,7 +578,6 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
{
*(Elf32_Half*) reloc_addr = (finaladdr + 0x8000) >> 16;
}
-#ifndef RTLD_BOOTSTRAP
else if (rinfo == R_PPC_REL24)
{
Elf32_Sword delta = finaladdr - (Elf32_Word) (char *) reloc_addr;
@@ -693,12 +697,14 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
#endif
}
+#ifndef RTLD_BOOTSTRAP
if (rinfo == R_PPC_ADDR16_LO ||
rinfo == R_PPC_ADDR16_HI ||
rinfo == R_PPC_ADDR16_HA ||
rinfo == R_PPC_REL24 ||
rinfo == R_PPC_ADDR24)
MODIFIED_CODE_NOQUEUE (reloc_addr);
+#endif
}
#define ELF_MACHINE_NO_REL 1
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-14 19:25:50 +0000