PowerPC64 ELFv2 ABI 5/6: LD_AUDIT interface changes

The ELFv2 ABI changes the calling convention by passing and returning
structures in registers in more cases than the old ABI:
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01145.html
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01147.html

For the most part, this does not affect glibc, since glibc assembler
files do not use structure parameters / return values.  However, one
place is affected: the LD_AUDIT interface provides a structure to
the audit routine that contains all registers holding function
argument and return values for the intercepted PLT call.

Since the new ABI now sometimes uses registers to return values
that were never used for this purpose in the old ABI, this structure
has to be extended.  To force audit routines to be modified for the
new ABI if necessary, the patch defines v2 variants of the la_ppc64
types and routines.

In addition, the patch contains two unrelated changes to the
PLT trampoline routines: it fixes a bug where FPR return values
were stored in the wrong place, and it removes the unnecessary
save/restore of CR.
This commit is contained in:
Ulrich Weigand 2013-12-04 06:59:37 -06:00 committed by Adhemerval Zanella
parent 8b8a692cfd
commit 61cd8fe401
6 changed files with 186 additions and 45 deletions

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@ -1,3 +1,26 @@
2013-11-12 Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Alan Modra <amodra@gmail.com>
* sysdeps/powerpc/bits/link.h (La_ppc64v2_regs, La_ppc64v2_retval):
New versions for use with the ELFv2 ABI.
(la_ppc64v2_gnu_pltenter, la_ppc64v2_gnu_pltexit): Add prototypes.
* sysdeps/powerpc/lsdodefs.h (struct La_ppc64v2_regs): Add forward
declaration.
(struct La_ppc64v2_retval): Likewise.
(ARCH_PLTENTER_MEMBERS): Add ppc64v2_gnu_pltenter.
(ARCH_PLTEXIT_MEMBERS): Add ppc64v2_gnu_pltexit.
* sysdeps/powerpc/powerpc64/dl-machine.h (ARCH_LA_PLTENTER): Define
to ppc64v2_gnu_pltenter if _CALL_ELF == 2.
(ARCH_LA_PLTEXIT): Define to ppc64v2_gnu_pltexit if _CALL_ELF == 2.
* sysdeps/powerpc/powerpc64/dl-trampoline.S (_dl_runtime_resolve):
Do not save or restore CR.
(FRAME_SIZE, VR_RTN): Provide updated values for _CALL_ELF == 2.
(_dl_profile_resolve): Do no save or restore CR. Support extended
return values for ELFv2 ABI. Fix location of FPR return registers.
* sysdeps/powerpc/powerpc64/tst-audit.h (pltenter, pltexit): Provide
updated values for _CALL_ELF == 2.
(La_regs, La_retval, int_retval): Likewise.
2013-12-04 Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
* sysdeps/powerpc/powerpc64/sysdep.h (FRAME_MIN_SIZE): Define.

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@ -63,7 +63,7 @@ extern unsigned int la_ppc32_gnu_pltexit (Elf32_Sym *__sym,
__END_DECLS
#else
#elif _CALL_ELF != 2
/* Registers for entry into PLT on PPC64. */
typedef struct La_ppc64_regs
@ -107,4 +107,48 @@ extern unsigned int la_ppc64_gnu_pltexit (Elf64_Sym *__sym,
__END_DECLS
#else
/* Registers for entry into PLT on PPC64 in the ELFv2 ABI. */
typedef struct La_ppc64v2_regs
{
uint64_t lr_reg[8];
double lr_fp[13];
uint32_t __padding;
uint32_t lr_vrsave;
uint32_t lr_vreg[12][4] __attribute__ ((aligned (16)));
uint64_t lr_r1;
uint64_t lr_lr;
} La_ppc64v2_regs;
/* Return values for calls from PLT on PPC64 in the ELFv2 ABI. */
typedef struct La_ppc64v2_retval
{
uint64_t lrv_r3;
uint64_t lrv_r4;
double lrv_fp[10];
uint32_t lrv_vreg[8][4] __attribute__ ((aligned (16)));
} La_ppc64v2_retval;
__BEGIN_DECLS
extern Elf64_Addr la_ppc64v2_gnu_pltenter (Elf64_Sym *__sym,
unsigned int __ndx,
uintptr_t *__refcook,
uintptr_t *__defcook,
La_ppc64v2_regs *__regs,
unsigned int *__flags,
const char *__symname,
long int *__framesizep);
extern unsigned int la_ppc64v2_gnu_pltexit (Elf64_Sym *__sym,
unsigned int __ndx,
uintptr_t *__refcook,
uintptr_t *__defcook,
const La_ppc64v2_regs *__inregs,
La_ppc64v2_retval *__outregs,
const char *__symname);
__END_DECLS
#endif

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@ -25,6 +25,8 @@ struct La_ppc32_regs;
struct La_ppc32_retval;
struct La_ppc64_regs;
struct La_ppc64_retval;
struct La_ppc64v2_regs;
struct La_ppc64v2_retval;
#define ARCH_PLTENTER_MEMBERS \
Elf32_Addr (*ppc32_gnu_pltenter) (Elf32_Sym *, unsigned int, uintptr_t *, \
@ -34,7 +36,12 @@ struct La_ppc64_retval;
Elf64_Addr (*ppc64_gnu_pltenter) (Elf64_Sym *, unsigned int, uintptr_t *, \
uintptr_t *, struct La_ppc64_regs *, \
unsigned int *, const char *name, \
long int *framesizep)
long int *framesizep); \
Elf64_Addr (*ppc64v2_gnu_pltenter) (Elf64_Sym *, unsigned int, \
uintptr_t *, uintptr_t *, \
struct La_ppc64v2_regs *, \
unsigned int *, const char *name, \
long int *framesizep)
#define ARCH_PLTEXIT_MEMBERS \
unsigned int (*ppc32_gnu_pltexit) (Elf32_Sym *, unsigned int, \
@ -47,7 +54,14 @@ struct La_ppc64_retval;
uintptr_t *, \
uintptr_t *, \
const struct La_ppc64_regs *, \
struct La_ppc64_retval *, const char *)
struct La_ppc64_retval *, \
const char *); \
unsigned int (*ppc64v2_gnu_pltexit) (Elf64_Sym *, unsigned int, \
uintptr_t *, \
uintptr_t *, \
const struct La_ppc64v2_regs *,\
struct La_ppc64v2_retval *, \
const char *)
#include_next <ldsodefs.h>

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@ -545,8 +545,13 @@ elf_machine_plt_value (struct link_map *map, const Elf64_Rela *reloc,
/* Names of the architecture-specific auditing callback functions. */
#if _CALL_ELF != 2
#define ARCH_LA_PLTENTER ppc64_gnu_pltenter
#define ARCH_LA_PLTEXIT ppc64_gnu_pltexit
#else
#define ARCH_LA_PLTENTER ppc64v2_gnu_pltenter
#define ARCH_LA_PLTEXIT ppc64v2_gnu_pltexit
#endif
#endif /* dl_machine_h */

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@ -50,11 +50,8 @@ EALIGN(_dl_runtime_resolve, 4, 0)
/* Store the LR in the LR Save area. */
std r0,FRAME_SIZE+FRAME_LR_SAVE(r1)
cfi_offset (lr, FRAME_LR_SAVE)
mfcr r0
std r9,INT_PARMS+48(r1)
std r10,INT_PARMS+56(r1)
/* I'm almost certain we don't have to save cr... be safe. */
std r0,FRAME_SIZE+FRAME_CR_SAVE(r1)
bl JUMPTARGET(_dl_fixup)
#ifndef SHARED
nop
@ -66,11 +63,9 @@ EALIGN(_dl_runtime_resolve, 4, 0)
ld r8,INT_PARMS+40(r1)
ld r7,INT_PARMS+32(r1)
mtlr r0
ld r0,FRAME_SIZE+FRAME_CR_SAVE(r1)
ld r6,INT_PARMS+24(r1)
ld r5,INT_PARMS+16(r1)
ld r4,INT_PARMS+8(r1)
mtcrf 0xFF,r0
/* Prepare for calling the function returned by fixup. */
PPC64_LOAD_FUNCPTR r3
ld r3,INT_PARMS+0(r1)
@ -85,18 +80,30 @@ END(_dl_runtime_resolve)
#undef FRAME_SIZE
#undef INT_PARMS
/* Stack layout:
(Note: some of these are not required for the ELFv2 ABI.)
+592 previous backchain
+584 spill_r31
+576 spill_r30
+560 v1
+552 fp4
+544 fp3
+536 fp2
+528 fp1
+520 r4
+512 r3
/* Stack layout: ELFv2 ABI.
+752 previous backchain
+744 spill_r31
+736 spill_r30
+720 v8
+704 v7
+688 v6
+672 v5
+656 v4
+640 v3
+624 v2
+608 v1
+600 fp10
ELFv1 ABI +592 fp9
+592 previous backchain +584 fp8
+584 spill_r31 +576 fp7
+576 spill_r30 +568 fp6
+560 v1 +560 fp5
+552 fp4 +552 fp4
+544 fp3 +544 fp3
+536 fp2 +536 fp2
+528 fp1 +528 fp1
+520 r4 +520 r4
+512 r3 +512 r3
return values
+504 free
+496 stackframe
@ -157,10 +164,15 @@ END(_dl_runtime_resolve)
+8 CR save area
r1+0 stack back chain
*/
#define FRAME_SIZE 592
#if _CALL_ELF == 2
# define FRAME_SIZE 752
# define VR_RTN 608
#else
# define FRAME_SIZE 592
# define VR_RTN 560
#endif
#define INT_RTN 512
#define FPR_RTN 528
#define VR_RTN 560
#define STACK_FRAME 496
#define CALLING_LR 488
#define CALLING_SP 480
@ -205,18 +217,14 @@ EALIGN(_dl_profile_resolve, 4, 0)
mflr r5
std r7,INT_PARMS+32(r1)
std r8,INT_PARMS+40(r1)
/* Store the LR in the LR Save area of the previous frame. */
/* XXX Do we have to do this? */
/* Store the LR in the LR Save area. */
la r8,FRAME_SIZE(r1)
std r5,FRAME_SIZE+FRAME_LR_SAVE(r1)
cfi_offset (lr, FRAME_LR_SAVE)
std r5,CALLING_LR(r1)
mfcr r0
std r9,INT_PARMS+48(r1)
std r10,INT_PARMS+56(r1)
std r8,CALLING_SP(r1)
/* I'm almost certain we don't have to save cr... be safe. */
std r0,FRAME_SIZE+FRAME_CR_SAVE(r1)
ld r12,.LC__dl_hwcap@toc(r2)
#ifdef SHARED
/* Load _rtld_local_ro._dl_hwcap. */
@ -319,11 +327,9 @@ L(restoreFXR):
ld r8,INT_PARMS+40(r1)
ld r7,INT_PARMS+32(r1)
mtlr r0
ld r0,FRAME_SIZE+FRAME_CR_SAVE(r1)
ld r6,INT_PARMS+24(r1)
ld r5,INT_PARMS+16(r1)
ld r4,INT_PARMS+8(r1)
mtcrf 0xFF,r0
/* Prepare for calling the function returned by fixup. */
PPC64_LOAD_FUNCPTR r3
ld r3,INT_PARMS+0(r1)
@ -346,10 +352,11 @@ L(restoreFXR):
lfd fp12,FPR_PARMS+88(r1)
lfd fp13,FPR_PARMS+96(r1)
/* Unwind the stack frame, and jump. */
ld r31,584(r1)
ld r30,576(r1)
ld r31,FRAME_SIZE-8(r1)
ld r30,FRAME_SIZE-16(r1)
addi r1,r1,FRAME_SIZE
bctr
L(do_pltexit):
la r10,(VR_PARMS+0)(r1)
la r9,(VR_PARMS+16)(r1)
@ -383,11 +390,9 @@ L(restoreFXR2):
ld r8,INT_PARMS+40(r1)
ld r7,INT_PARMS+32(r1)
mtlr r0
ld r0,FRAME_SIZE+FRAME_CR_SAVE(r1)
ld r6,INT_PARMS+24(r1)
ld r5,INT_PARMS+16(r1)
ld r4,INT_PARMS+8(r1)
mtcrf 0xFF,r0
/* Prepare for calling the function returned by fixup. */
std r2,FRAME_TOC_SAVE(r1)
PPC64_LOAD_FUNCPTR r3
@ -413,16 +418,37 @@ L(restoreFXR2):
/* But return here and store the return values. */
std r3,INT_RTN(r1)
std r4,INT_RTN+8(r1)
stfd fp1,FPR_PARMS+0(r1)
stfd fp2,FPR_PARMS+8(r1)
stfd fp1,FPR_RTN+0(r1)
stfd fp2,FPR_RTN+8(r1)
cmpdi cr0,r12,0
la r10,VR_RTN(r1)
stfd fp3,FPR_PARMS+16(r1)
stfd fp4,FPR_PARMS+24(r1)
stfd fp3,FPR_RTN+16(r1)
stfd fp4,FPR_RTN+24(r1)
#if _CALL_ELF == 2
la r12,VR_RTN+16(r1)
stfd fp5,FPR_RTN+32(r1)
stfd fp6,FPR_RTN+40(r1)
li r5,32
li r6,64
stfd fp7,FPR_RTN+48(r1)
stfd fp8,FPR_RTN+56(r1)
stfd fp9,FPR_RTN+64(r1)
stfd fp10,FPR_RTN+72(r1)
#endif
mr r3,r31
mr r4,r30
beq L(callpltexit)
stvx v2,0,r10
#if _CALL_ELF == 2
stvx v3,0,r12
stvx v4,r5,r10
stvx v5,r5,r12
addi r5,r5,64
stvx v6,r6,r10
stvx v7,r6,r12
stvx v8,r5,r10
stvx v9,r5,r12
#endif
L(callpltexit):
addi r5,r1,INT_PARMS
addi r6,r1,INT_RTN
@ -434,18 +460,39 @@ L(callpltexit):
lwz r12,VR_VRSAVE(r1)
ld r3,INT_RTN(r1)
ld r4,INT_RTN+8(r1)
lfd fp1,FPR_PARMS+0(r1)
lfd fp2,FPR_PARMS+8(r1)
lfd fp1,FPR_RTN+0(r1)
lfd fp2,FPR_RTN+8(r1)
cmpdi cr0,r12,0
la r10,VR_RTN(r1)
lfd fp3,FPR_PARMS+16(r1)
lfd fp4,FPR_PARMS+24(r1)
la r11,VR_RTN(r1)
lfd fp3,FPR_RTN+16(r1)
lfd fp4,FPR_RTN+24(r1)
#if _CALL_ELF == 2
la r12,VR_RTN+16(r1)
lfd fp5,FPR_RTN+32(r1)
lfd fp6,FPR_RTN+40(r1)
li r30,32
li r31,64
lfd fp7,FPR_RTN+48(r1)
lfd fp8,FPR_RTN+56(r1)
lfd fp9,FPR_RTN+64(r1)
lfd fp10,FPR_RTN+72(r1)
#endif
beq L(pltexitreturn)
lvx v2,0,r10
lvx v2,0,r11
#if _CALL_ELF == 2
lvx v3,0,r12
lvx v4,r30,r11
lvx v5,r30,r12
addi r30,r30,64
lvx v6,r31,r11
lvx v7,r31,r12
lvx v8,r30,r11
lvx v9,r30,r12
#endif
L(pltexitreturn):
ld r0,FRAME_SIZE+FRAME_LR_SAVE(r1)
ld r31,584(r1)
ld r30,576(r1)
ld r31,FRAME_SIZE-8(r1)
ld r30,FRAME_SIZE-16(r1)
mtlr r0
ld r1,0(r1)
blr

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@ -18,8 +18,16 @@
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#if _CALL_ELF != 2
#define pltenter la_ppc64_gnu_pltenter
#define pltexit la_ppc64_gnu_pltexit
#define La_regs La_ppc64_regs
#define La_retval La_ppc64_retval
#define int_retval lrv_r3
#else
#define pltenter la_ppc64v2_gnu_pltenter
#define pltexit la_ppc64v2_gnu_pltexit
#define La_regs La_ppc64v2_regs
#define La_retval La_ppc64v2_retval
#define int_retval lrv_r3
#endif