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Diffstat (limited to 'libc/string/generic/bp-checks.h')
| -rw-r--r-- | libc/string/generic/bp-checks.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/libc/string/generic/bp-checks.h b/libc/string/generic/bp-checks.h new file mode 100644 index 000000000..efbb84716 --- /dev/null +++ b/libc/string/generic/bp-checks.h @@ -0,0 +1,129 @@ +/* Bounded-pointer checking macros for C. + Copyright (C) 2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Greg McGary <greg@mcgary.org> + + 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_checks_h_ +#define _bp_checks_h_ 1 + +#if __BOUNDED_POINTERS__ + +# define BOUNDS_VIOLATED (__builtin_trap (), 0) + +/* Verify that pointer's value >= low. Return pointer value. */ +# define CHECK_BOUNDS_LOW(ARG) \ + (((__ptrvalue (ARG) < __ptrlow (ARG)) && BOUNDS_VIOLATED), \ + __ptrvalue (ARG)) + +/* Verify that pointer's value < high. Return pointer value. */ +# define CHECK_BOUNDS_HIGH(ARG) \ + (((__ptrvalue (ARG) > __ptrhigh (ARG)) && BOUNDS_VIOLATED), \ + __ptrvalue (ARG)) + +# define _CHECK_N(ARG, N, COND) \ + (((COND) \ + && (__ptrvalue (ARG) < __ptrlow (ARG) \ + || __ptrvalue (ARG) + (N) > __ptrhigh (ARG)) \ + && BOUNDS_VIOLATED), \ + __ptrvalue (ARG)) + +extern void *__unbounded __ubp_memchr (const void *__unbounded, int, unsigned); + +# define _CHECK_STRING(ARG, COND) \ + (((COND) \ + && (__ptrvalue (ARG) < __ptrlow (ARG) \ + || !__ubp_memchr (__ptrvalue (ARG), '\0', \ + (__ptrhigh (ARG) - __ptrvalue (ARG)))) \ + && BOUNDS_VIOLATED), \ + __ptrvalue (ARG)) + +/* Check bounds of a pointer seated to an array of N objects. */ +# define CHECK_N(ARG, N) _CHECK_N ((ARG), (N), 1) +/* Same as CHECK_N, but tolerate ARG == NULL. */ +# define CHECK_N_NULL_OK(ARG, N) _CHECK_N ((ARG), (N), __ptrvalue (ARG)) + +/* Check bounds of a pointer seated to a single object. */ +# define CHECK_1(ARG) CHECK_N ((ARG), 1) +/* Same as CHECK_1, but tolerate ARG == NULL. */ +# define CHECK_1_NULL_OK(ARG) CHECK_N_NULL_OK ((ARG), 1) + +/* Check for NUL-terminator within string's bounds. */ +# define CHECK_STRING(ARG) _CHECK_STRING ((ARG), 1) +/* Same as CHECK_STRING, but tolerate ARG == NULL. */ +# define CHECK_STRING_NULL_OK(ARG) _CHECK_STRING ((ARG), __ptrvalue (ARG)) + +/* Check bounds of signal syscall args with type sigset_t. */ +# define CHECK_SIGSET(SET) CHECK_N ((SET), _NSIG / (8 * sizeof *(SET))) +/* Same as CHECK_SIGSET, but tolerate SET == NULL. */ +# define CHECK_SIGSET_NULL_OK(SET) CHECK_N_NULL_OK ((SET), _NSIG / (8 * sizeof *(SET))) + +# if defined (_IOC_SIZESHIFT) && defined (_IOC_SIZEBITS) +/* Extract the size of the ioctl data and check its bounds. */ +# define CHECK_IOCTL(ARG, CMD) \ + CHECK_N ((const char *) (ARG), \ + (((CMD) >> _IOC_SIZESHIFT) & ((1 << _IOC_SIZEBITS) - 1))) +# else +/* We don't know the size of the ioctl data, so the best we can do + is check that the first byte is within bounds. */ +# define CHECK_IOCTL(ARG, CMD) CHECK_1 ((const char *) ARG) +# endif + +/* Check bounds of `struct flock *' for the locking fcntl commands. */ +# define CHECK_FCNTL(ARG, CMD) \ + (((CMD) == F_GETLK || (CMD) == F_SETLK || (CMD) == F_SETLKW) \ + ? CHECK_1 ((struct flock *) ARG) : (unsigned long) (ARG)) + +/* Check bounds of an array of mincore residency-status flags that + cover a region of NBYTES. Such a vector occupies one byte per page + of memory. */ +# define CHECK_N_PAGES(ARG, NBYTES) \ + ({ int _page_size_ = sysconf (_SC_PAGE_SIZE); \ + CHECK_N ((const char *) (ARG), \ + ((NBYTES) + _page_size_ - 1) / _page_size_); }) + +/* Return a bounded pointer with value PTR that satisfies CHECK_N (PTR, N). */ +# define BOUNDED_N(PTR, N) \ + ({ __typeof (PTR) __bounded _p_; \ + __ptrvalue _p_ = __ptrlow _p_ = __ptrvalue (PTR); \ + __ptrhigh _p_ = __ptrvalue _p_ + (N); \ + _p_; }) + +#else /* !__BOUNDED_POINTERS__ */ + +/* Do nothing if not compiling with -fbounded-pointers. */ + +# define BOUNDS_VIOLATED +# define CHECK_BOUNDS_LOW(ARG) (ARG) +# define CHECK_BOUNDS_HIGH(ARG) (ARG) +# define CHECK_1(ARG) (ARG) +# define CHECK_1_NULL_OK(ARG) (ARG) +# define CHECK_N(ARG, N) (ARG) +# define CHECK_N_NULL_OK(ARG, N) (ARG) +# define CHECK_STRING(ARG) (ARG) +# define CHECK_SIGSET(SET) (SET) +# define CHECK_SIGSET_NULL_OK(SET) (SET) +# define CHECK_IOCTL(ARG, CMD) (ARG) +# define CHECK_FCNTL(ARG, CMD) (ARG) +# define CHECK_N_PAGES(ARG, NBYTES) (ARG) +# define BOUNDED_N(PTR, N) (PTR) + +#endif /* !__BOUNDED_POINTERS__ */ + +#define BOUNDED_1(PTR) BOUNDED_N (PTR, 1) + +#endif /* _bp_checks_h_ */ |