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18173559a2
Fix usage of tabort in generated syscalls. r0 has special meaning when used with this instruction, thus it will not generate persistent errors, nor return an error code. This mitigates poor CPU usage when performing elided critical sections. Additionally, transactions should be aborted when entering a user invoked syscall. Otherwise the results of the transaction may be undefined. 2015-08-25 Paul E. Murphy <murphyp@linux.vnet.ibm.com> * sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION): Use register other than r0 for tabort, it has special meaning. * sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION): Likewise * sysdeps/unix.sysv/linux/powerpc/syscall.S (syscall): Abort transaction before starting syscall.
175 lines
4.8 KiB
C
175 lines
4.8 KiB
C
/* Assembly macros for 32-bit PowerPC.
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Copyright (C) 1999-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdeps/powerpc/sysdep.h>
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#ifdef __ASSEMBLER__
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/* If compiled for profiling, call `_mcount' at the start of each
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function. */
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#ifdef PROF
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/* The mcount code relies on a the return address being on the stack
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to locate our caller and so it can restore it; so store one just
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for its benefit. */
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# define CALL_MCOUNT \
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mflr r0; \
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stw r0,4(r1); \
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cfi_offset (lr, 4); \
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bl JUMPTARGET(_mcount);
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#else /* PROF */
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# define CALL_MCOUNT /* Do nothing. */
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#endif /* PROF */
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#define ENTRY(name) \
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.globl C_SYMBOL_NAME(name); \
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.type C_SYMBOL_NAME(name),@function; \
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.align ALIGNARG(2); \
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C_LABEL(name) \
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cfi_startproc; \
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CALL_MCOUNT
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/* helper macro for accessing the 32-bit powerpc GOT. */
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#define SETUP_GOT_ACCESS(regname,GOT_LABEL) \
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bcl 20,31,GOT_LABEL ; \
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GOT_LABEL: ; \
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mflr (regname)
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#define EALIGN_W_0 /* No words to insert. */
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#define EALIGN_W_1 nop
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#define EALIGN_W_2 nop;nop
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#define EALIGN_W_3 nop;nop;nop
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#define EALIGN_W_4 EALIGN_W_3;nop
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#define EALIGN_W_5 EALIGN_W_4;nop
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#define EALIGN_W_6 EALIGN_W_5;nop
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#define EALIGN_W_7 EALIGN_W_6;nop
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/* EALIGN is like ENTRY, but does alignment to 'words'*4 bytes
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past a 2^align boundary. */
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#ifdef PROF
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# define EALIGN(name, alignt, words) \
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.globl C_SYMBOL_NAME(name); \
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.type C_SYMBOL_NAME(name),@function; \
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.align ALIGNARG(2); \
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C_LABEL(name) \
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cfi_startproc; \
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CALL_MCOUNT \
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b 0f; \
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.align ALIGNARG(alignt); \
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EALIGN_W_##words; \
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0:
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#else /* PROF */
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# define EALIGN(name, alignt, words) \
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.globl C_SYMBOL_NAME(name); \
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.type C_SYMBOL_NAME(name),@function; \
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.align ALIGNARG(alignt); \
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EALIGN_W_##words; \
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C_LABEL(name) \
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cfi_startproc;
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#endif
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#undef END
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#define END(name) \
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cfi_endproc; \
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ASM_SIZE_DIRECTIVE(name)
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#if ! IS_IN(rtld) && defined (ENABLE_LOCK_ELISION)
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# define ABORT_TRANSACTION \
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cmpwi 2,0; \
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beq 1f; \
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lwz 0,TM_CAPABLE(2); \
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cmpwi 0,0; \
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beq 1f; \
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li 11,_ABORT_SYSCALL; \
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tabort. 11; \
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.align 4; \
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1:
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#else
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# define ABORT_TRANSACTION
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#endif
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#define DO_CALL(syscall) \
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ABORT_TRANSACTION \
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li 0,syscall; \
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sc
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#undef JUMPTARGET
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#ifdef PIC
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# define JUMPTARGET(name) name##@plt
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#else
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# define JUMPTARGET(name) name
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#endif
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#if defined SHARED && defined PIC && !defined NO_HIDDEN
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# undef HIDDEN_JUMPTARGET
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# define HIDDEN_JUMPTARGET(name) __GI_##name##@local
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#endif
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#define PSEUDO(name, syscall_name, args) \
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.section ".text"; \
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ENTRY (name) \
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DO_CALL (SYS_ify (syscall_name));
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#define PSEUDO_RET \
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bnslr+; \
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b __syscall_error@local
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#define ret PSEUDO_RET
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#undef PSEUDO_END
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#define PSEUDO_END(name) \
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END (name)
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#define PSEUDO_NOERRNO(name, syscall_name, args) \
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.section ".text"; \
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ENTRY (name) \
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DO_CALL (SYS_ify (syscall_name));
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#define PSEUDO_RET_NOERRNO \
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blr
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#define ret_NOERRNO PSEUDO_RET_NOERRNO
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#undef PSEUDO_END_NOERRNO
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#define PSEUDO_END_NOERRNO(name) \
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END (name)
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#define PSEUDO_ERRVAL(name, syscall_name, args) \
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.section ".text"; \
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ENTRY (name) \
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DO_CALL (SYS_ify (syscall_name));
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#define PSEUDO_RET_ERRVAL \
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blr
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#define ret_ERRVAL PSEUDO_RET_ERRVAL
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#undef PSEUDO_END_ERRVAL
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#define PSEUDO_END_ERRVAL(name) \
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END (name)
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/* Local labels stripped out by the linker. */
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#undef L
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#define L(x) .L##x
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#define XGLUE(a,b) a##b
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#define GLUE(a,b) XGLUE (a,b)
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#define GENERATE_GOT_LABEL(name) GLUE (.got_label, name)
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/* Label in text section. */
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#define C_TEXT(name) name
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#endif /* __ASSEMBLER__ */
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