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56cf276381
Linux kernel powerpc documentation states issuing a syscall inside a transaction is not recommended and may lead to undefined behavior. It also states syscalls does not abort transactoin neither they run in transactional state. To avoid side-effects being visible outside transactions, GLIBC with lock elision enabled will issue a transaction abort instruction just before all syscalls if hardware supports hardware transactions.
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 0,_ABORT_SYSCALL; \
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tabort. 0; \
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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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