PowerPC64 ELFv2 ABI 1/6: Code refactoring

This is the first patch to support the new ELFv2 ABI in glibc.

As preparation, this patch simply refactors some of the powerpc64 assembler
code to move all code related to creating function descriptors (.opd section)
or using function descriptors (function pointer call) into a central place
in sysdep.h.

Note that most locations creating .opd entries were already using macros
in sysdep.h, this patch simply extends this to the remaining places.

No relevant change in generated code expected.

diff --git a/ChangeLog b/ChangeLog
index f56f9f6920a978174425956e8f906f5364b5ad7a..61302a4c24a13ba397536b233daf29ad08e06efc 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,21 @@
+2013-12-04  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
+
+       * sysdeps/powerpc/powerpc64/sysdep.h [ASSEMBLER] (PPC64_LOAD_FUNCPTR):
+       New assembler macro.
+       [ASSEMBLER] (ENTRY_1): Do not switch to .text section here ...
+       [ASSEMBLER] (ENTRY): ... but instead here ...
+       [ASSEMBLER] (EALIGN): ... and here.
+       [!ASSEMBLER] (PPC64_LOAD_FUNCPTR): New macro.
+       [!ASSEMBLER] (ENTRY_1): New macro; set up .opd entry.
+       [!ASSEMBLER] (ENTRY_2): Use it.
+       * sysdeps/powerpc/powerpc64/dl-machine.h (RTLD_START): Update for
+       ENTRY_2 changes.  Use PPC64_LOAD_FUNCPTR.
+       * sysdeps/powerpc/powerpc64/dl-trampoline.S (_dl_runtime_resolve,
+       _dl_profile_resolve): Use PPC64_LOAD_FUNCPTR.
+       * sysdeps/powerpc/powerpc64/crti.S (_init, _fini): Use ENTRY_2.
+       * sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (clone):
+       Use PPC64_LOAD_FUNCPTR.
+
 2013-12-04  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
 
        * sysdeps/powerpc/tls.h (tcbhead_t): Add __private_ss field.

diff --git a/sysdeps/powerpc/powerpc64/crti.S b/sysdeps/powerpc/powerpc64/crti.S
index 967dc669bb979c088e0284beadb4c071c72a930d..116199da6b9528b60f6c06dff1fa7641d2c453e2 100644 (file)
--- a/sysdeps/powerpc/powerpc64/crti.S
+++ b/sysdeps/powerpc/powerpc64/crti.S
@@ -59,19 +59,9 @@
        .section ".toc", "aw"
 .LC0:
        .tc PREINIT_FUNCTION[TC], PREINIT_FUNCTION
-#endif
-       .type BODY_LABEL (_init), @function
-       .globl _init
-       .section ".opd", "aw"
-       .align 3
-_init: OPD_ENT (_init)
-#ifdef HAVE_ASM_GLOBAL_DOT_NAME
-       .globl BODY_LABEL (_init)
-       .size _init, 24
-#else
-       .type _init, @function
 #endif
        .section ".init", "ax", @progbits
+       ENTRY_2(_init)
        .align ALIGNARG (2)
 BODY_LABEL (_init):
        mflr 0
@@ -87,18 +77,8 @@ BODY_LABEL (_init):
        nop
 1:
 
-       .type BODY_LABEL (_fini), @function
-       .globl _fini
-       .section ".opd", "aw"
-       .align 3
-_fini: OPD_ENT (_fini)
-#ifdef HAVE_ASM_GLOBAL_DOT_NAME
-       .globl BODY_LABEL (_fini)
-       .size _fini, 24
-#else
-       .type _fini, @function
-#endif
        .section ".fini", "ax", @progbits
+       ENTRY_2(_fini)
        .align ALIGNARG (2)
 BODY_LABEL (_fini):
        mflr 0

diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h
index 19fa4fab4bcea34f9778060de44aca6a34bcf340..a623be5f0bb7c343f430578c5f64b12661b14d5f 100644 (file)
--- a/sysdeps/powerpc/powerpc64/dl-machine.h
+++ b/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -122,14 +122,7 @@ elf_machine_dynamic (void)
 #define RTLD_START \
   asm (".pushsection \".text\"\n"                                      \
 "      .align  2\n"                                                    \
-"      .type   " BODY_PREFIX "_start,@function\n"                      \
-"      .pushsection \".opd\",\"aw\"\n"                                 \
-"      .align  3\n"                                                    \
-"      .globl  _start\n"                                               \
 "      " ENTRY_2(_start) "\n"                                          \
-"_start:\n"                                                            \
-"      " OPD_ENT(_start) "\n"                                          \
-"      .popsection\n"                                                  \
 BODY_PREFIX "_start:\n"                                                        \
 /* We start with the following on the stack, from top:                 \
    argc (4 bytes);                                                     \
@@ -154,11 +147,6 @@ BODY_PREFIX "_start:\n"                                                    \
 ".LT__start_name_end:\n"                                               \
 "      .align 2\n"                                                     \
 "      " END_2(_start) "\n"                                            \
-"      .globl  _dl_start_user\n"                                       \
-"      .pushsection \".opd\",\"aw\"\n"                                 \
-"_dl_start_user:\n"                                                    \
-"      " OPD_ENT(_dl_start_user) "\n"                                  \
-"      .popsection\n"                                                  \
 "      .pushsection    \".toc\",\"aw\"\n"                              \
 DL_STARTING_UP_DEF                                                     \
 ".LC__rtld_local:\n"                                                   \
@@ -170,7 +158,6 @@ DL_STARTING_UP_DEF                                                  \
 ".LC__dl_fini:\n"                                                      \
 "      .tc _dl_fini[TC],_dl_fini\n"                                    \
 "      .popsection\n"                                                  \
-"      .type   " BODY_PREFIX "_dl_start_user,@function\n"              \
 "      " ENTRY_2(_dl_start_user) "\n"                                  \
 /* Now, we do our main work of calling initialisation procedures.      \
    The ELF ABI doesn't say anything about parameters for these,                \
@@ -228,10 +215,7 @@ BODY_PREFIX "_dl_start_user:\n"                                            \
 /* Now, call the start function descriptor at r30...  */               \
 "      .globl  ._dl_main_dispatch\n"                                   \
 "._dl_main_dispatch:\n"                                                        \
-"      ld      0,0(30)\n"                                              \
-"      ld      2,8(30)\n"                                              \
-"      mtctr   0\n"                                                    \
-"      ld      11,16(30)\n"                                            \
+"      " PPC64_LOAD_FUNCPTR(30) "\n"                                   \
 "      bctr\n"                                                         \
 ".LT__dl_start_user:\n"                                                        \
 "      .long 0\n"                                                      \

diff --git a/sysdeps/powerpc/powerpc64/dl-trampoline.S b/sysdeps/powerpc/powerpc64/dl-trampoline.S
index 4dde2763a3df73d99f5adfa79987b327f2513beb..bffc4cbab6b9435fa5656f66d1733e0edf720d71 100644 (file)
--- a/sysdeps/powerpc/powerpc64/dl-trampoline.S
+++ b/sysdeps/powerpc/powerpc64/dl-trampoline.S
@@ -71,12 +71,8 @@ EALIGN(_dl_runtime_resolve, 4, 0)
        ld      r5,INT_PARMS+16(r1)
        ld      r4,INT_PARMS+8(r1)
        mtcrf   0xFF,r0
-/* Load the target address, toc and static chain reg from the function
-   descriptor returned by fixup.  */
-       ld      r0,0(r3)
-       ld      r2,8(r3)
-       mtctr   r0
-       ld      r11,16(r3)
+/* Prepare for calling the function returned by fixup.  */
+       PPC64_LOAD_FUNCPTR r3
        ld      r3,INT_PARMS+0(r1)
 /* Unwind the stack frame, and jump.  */
        addi    r1,r1,FRAME_SIZE
@@ -322,13 +318,9 @@ L(restoreFXR):
        ld      r5,INT_PARMS+16(r1)
        ld      r4,INT_PARMS+8(r1)
        mtcrf   0xFF,r0
-/* Load the target address, toc and static chain reg from the function
-   descriptor returned by fixup.  */
-       ld      r0,0(r3)
-       ld      r2,8(r3)
-       ld      r11,16(r3)
+/* Prepare for calling the function returned by fixup.  */
+       PPC64_LOAD_FUNCPTR r3
        ld      r3,INT_PARMS+0(r1)
-       mtctr   r0
 /* Load the floating point registers.  */
        lfd     fp1,FPR_PARMS+0(r1)
        lfd     fp2,FPR_PARMS+8(r1)
@@ -386,14 +378,10 @@ L(restoreFXR2):
        ld      r5,INT_PARMS+16(r1)
        ld      r4,INT_PARMS+8(r1)
        mtcrf   0xFF,r0
-/* Load the target address, toc and static chain reg from the function
-   descriptor returned by fixup.  */
-       ld      r0,0(r3)
+/* Prepare for calling the function returned by fixup.  */
        std     r2,40(r1)
-       ld      r2,8(r3)
-       ld      r11,16(r3)
+       PPC64_LOAD_FUNCPTR r3
        ld      r3,INT_PARMS+0(r1)
-       mtctr   r0
 /* Load the floating point registers.  */
        lfd     fp1,FPR_PARMS+0(r1)
        lfd     fp2,FPR_PARMS+8(r1)

diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index 57fa8ba78f686afcedac1cf5e52f904eb66f2680..cc89b3ce80b7363e7691786086a27da0dc5ee358 100644 (file)
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -74,6 +74,14 @@
 #endif
        .endm
 
+/* Macro to prepare for calling via a function pointer.  */
+       .macro PPC64_LOAD_FUNCPTR PTR
+       ld      r12,0(\PTR)
+       ld      r2,8(\PTR)
+       mtctr   r12
+       ld      r11,16(\PTR)
+       .endm
+
 #ifdef USE_PPC64_OVERLAPPING_OPD
 # define OPD_ENT(name) .quad BODY_LABEL (name), .TOC.@tocbase
 #else
@@ -81,7 +89,6 @@
 #endif
 
 #define ENTRY_1(name)  \
-       .section        ".text";                \
        .type BODY_LABEL(name),@function;       \
        .globl name;                            \
        .section ".opd","aw";                   \
@@ -110,6 +117,7 @@ name##: OPD_ENT (name);                             \
 #endif
 
 #define ENTRY(name)    \
+       .section        ".text";                \
        ENTRY_2(name)                           \
        .align ALIGNARG(2);                     \
 BODY_LABEL(name):                              \
@@ -127,6 +135,7 @@ BODY_LABEL(name):                           \
 /* EALIGN is like ENTRY, but does alignment to 'words'*4 bytes
    past a 2^alignt boundary.  */
 #define EALIGN(name, alignt, words) \
+       .section        ".text";                \
        ENTRY_2(name)                           \
        .align ALIGNARG(alignt);                \
        EALIGN_W_##words;                       \
@@ -286,24 +295,42 @@ LT_LABELSUFFIX(name,_name_end): ; \
 
 #else /* !__ASSEMBLER__ */
 
+#define PPC64_LOAD_FUNCPTR(ptr) \
+       "ld     12,0(" #ptr ");\n"                                      \
+       "ld     2,8(" #ptr ");\n"                                       \
+       "mtctr  12;\n"                                                  \
+       "ld     11,16(" #ptr ");"
+
 #ifdef USE_PPC64_OVERLAPPING_OPD
 # define OPD_ENT(name) ".quad " BODY_PREFIX #name ", .TOC.@tocbase;"
 #else
 # define OPD_ENT(name) ".quad " BODY_PREFIX #name ", .TOC.@tocbase, 0;"
 #endif
 
+#define ENTRY_1(name)  \
+       ".type   " BODY_PREFIX #name ",@function;\n"                    \
+       ".globl " #name ";\n"                                           \
+       ".pushsection \".opd\",\"aw\";\n"                               \
+       ".align  3;\n"                                                  \
+#name ":\n"                                                            \
+       OPD_ENT (name) "\n"                                             \
+       ".popsection;"
+
 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
 # define DOT_PREFIX "."
 # define BODY_PREFIX "."
 # define ENTRY_2(name) \
        ".globl " BODY_PREFIX #name ";\n"                               \
+       ENTRY_1(name) "\n"                                              \
        ".size  " #name ", 24;"
 # define END_2(name)   \
        ".size " BODY_PREFIX #name ",.-" BODY_PREFIX #name ";"
 #else
 # define DOT_PREFIX ""
 # define BODY_PREFIX ".LY"
-# define ENTRY_2(name) ".type " #name ",@function;"
+# define ENTRY_2(name) \
+       ".type " #name ",@function;\n"                                  \
+       ENTRY_1(name)
 # define END_2(name)   \
        ".size " #name ",.-" BODY_PREFIX #name ";\n"                    \
        ".size " BODY_PREFIX #name ",.-" BODY_PREFIX #name ";"

diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
index cf46856e1afa5c4f4c1399be298d04eb61a787f4..4151d15c377d2beba32094e7062550f3bc4058c6 100644 (file)
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
@@ -99,9 +99,7 @@ L(oldpid):
 
        std     r2,40(r1)
        /* Call procedure.  */
-       ld      r0,0(r30)
-       ld      r2,8(r30)
-       mtctr   r0
+       PPC64_LOAD_FUNCPTR r30
        mr      r3,r31
        bctrl
        ld      r2,40(r1)