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Diffstat (limited to 'sysdeps/x86_64/bp-asm.h')
| -rw-r--r-- | sysdeps/x86_64/bp-asm.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/sysdeps/x86_64/bp-asm.h b/sysdeps/x86_64/bp-asm.h new file mode 100644 index 0000000000..ff140ce181 --- /dev/null +++ b/sysdeps/x86_64/bp-asm.h @@ -0,0 +1,141 @@ +/* Bounded-pointer definitions for x86-64 assembler. + Copyright (C) 2001 Free Software Foundation, Inc. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _bp_asm_h_ +# define _bp_asm_h_ 1 + +# if __ASSEMBLER__ + +# if __BOUNDED_POINTERS__ + +/* Bounded pointers occupy three words. */ +# define PTR_SIZE 24 +/* Bounded pointer return values are passed back through a hidden + argument that points to caller-allocate space. The hidden arg + occupies one word on the stack. */ +# define RTN_SIZE 6 +/* Although the caller pushes the hidden arg, the callee is + responsible for popping it. */ +# define RET_PTR ret $RTN_SIZE +/* Maintain frame pointer chain in leaf assembler functions for the benefit + of debugging stack traces when bounds violations occur. */ +# define ENTER pushq %rbp; movq %rsp, %rbp +# define LEAVE movq %rbp, %rsp; popq %rbp +/* Stack space overhead of procedure-call linkage: return address and + frame pointer. */ +# define LINKAGE 16 +/* Stack offset of return address after calling ENTER. */ +# define PCOFF 8 + +/* Int 5 is the "bound range" exception also raised by the "bound" + instruction. */ +# define BOUNDS_VIOLATED int $5 + +# define CHECK_BOUNDS_LOW(VAL_REG, BP_MEM) \ + cmpq 8+BP_MEM, VAL_REG; \ + jae 0f; /* continue if value >= low */ \ + BOUNDS_VIOLATED; \ + 0: + +# define CHECK_BOUNDS_HIGH(VAL_REG, BP_MEM, Jcc) \ + cmpq 16+BP_MEM, VAL_REG; \ + Jcc 0f; /* continue if value < high */ \ + BOUNDS_VIOLATED; \ + 0: + +# define CHECK_BOUNDS_BOTH(VAL_REG, BP_MEM) \ + cmpq 8+BP_MEM, VAL_REG; \ + jb 1f; /* die if value < low */ \ + cmpq 16+BP_MEM, VAL_REG; \ + jb 0f; /* continue if value < high */ \ + 1: BOUNDS_VIOLATED; \ + 0: + +# define CHECK_BOUNDS_BOTH_WIDE(VAL_REG, BP_MEM, LENGTH) \ + CHECK_BOUNDS_LOW(VAL_REG, BP_MEM); \ + addl LENGTH, VAL_REG; \ + cmpq 16+BP_MEM, VAL_REG; \ + jbe 0f; /* continue if value <= high */ \ + BOUNDS_VIOLATED; \ + 0: subq LENGTH, VAL_REG /* restore value */ + +/* Take bounds from BP_MEM and affix them to the pointer + value in %rax, stuffing all into memory at RTN(%esp). + Use %rdx as a scratch register. */ + +# define RETURN_BOUNDED_POINTER(BP_MEM) \ + movq RTN(%rsp), %rdx; \ + movq %rax, 0(%rdx); \ + movq 8+BP_MEM, %rax; \ + movq %rax, 4(%rdx); \ + movq 16+BP_MEM, %rax; \ + movq %rax, 8(%rdx) + +# define RETURN_NULL_BOUNDED_POINTER \ + movl RTN(%rsp), %rdx; \ + movl %rax, 0(%rdx); \ + movl %rax, 4(%rdx); \ + movl %rax, 8(%rdx) + +/* The caller of __errno_location is responsible for allocating space + for the three-word BP return-value and passing pushing its address + as an implicit first argument. */ +# define PUSH_ERRNO_LOCATION_RETURN \ + subl $16, %esp; \ + subl $8, %esp; \ + pushq %rsp + +/* __errno_location is responsible for popping the implicit first + argument, but we must pop the space for the BP itself. We also + dereference the return value in order to dig out the pointer value. */ +# define POP_ERRNO_LOCATION_RETURN \ + popq %rax; \ + addq $16, %rsp + +# else /* !__BOUNDED_POINTERS__ */ + +/* Unbounded pointers occupy one word. */ +# define PTR_SIZE 8 +/* Unbounded pointer return values are passed back in the register %rax. */ +# define RTN_SIZE 0 +/* Use simple return instruction for unbounded pointer values. */ +# define RET_PTR ret +/* Don't maintain frame pointer chain for leaf assembler functions. */ +# define ENTER +# define LEAVE +/* Stack space overhead of procedure-call linkage: return address only. */ +# define LINKAGE 8 +/* Stack offset of return address after calling ENTER. */ +# define PCOFF 0 + +# define CHECK_BOUNDS_LOW(VAL_REG, BP_MEM) +# define CHECK_BOUNDS_HIGH(VAL_REG, BP_MEM, Jcc) +# define CHECK_BOUNDS_BOTH(VAL_REG, BP_MEM) +# define CHECK_BOUNDS_BOTH_WIDE(VAL_REG, BP_MEM, LENGTH) +# define RETURN_BOUNDED_POINTER(BP_MEM) + +# define RETURN_NULL_BOUNDED_POINTER + +# define PUSH_ERRNO_LOCATION_RETURN +# define POP_ERRNO_LOCATION_RETURN + +# endif /* !__BOUNDED_POINTERS__ */ + +# endif /* __ASSEMBLER__ */ + +#endif /* _bp_asm_h_ */ |