diff options
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | posix/tst-mmap-offset.c | 9 | ||||
| -rw-r--r-- | sysdeps/generic/mmap_info.h | 16 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/mips/mmap_info.h | 13 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/mmap64.c | 9 |
5 files changed, 53 insertions, 5 deletions
diff --git a/ChangeLog b/ChangeLog index d42f4faeb0..90675f699c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,14 @@ +2019-07-10 Adhemerval Zanella <adhemerval.zanella@linaro.org> + + [BZ #24699] + * posix/tst-mmap-offset.c: Mention BZ #24699. + (do_test_bz21270): Rename to do_test_large_offset and use + mmap64_maximum_offset to check for maximum expected offset value. + * sysdeps/generic/mmap_info.h: New file. + * sysdeps/unix/sysv/linux/mips/mmap_info.h: Likewise. + * sysdeps/unix/sysv/linux/mmap64.c (MMAP_OFF_HIGH_MASK): Define iff + __NR_mmap2 is used. + 2019-07-10 DJ Delorie <dj@redhat.com> Sergei Trofimovich <slyfox@inbox.ru> diff --git a/posix/tst-mmap-offset.c b/posix/tst-mmap-offset.c index 676c52845f..d4e53c3e67 100644 --- a/posix/tst-mmap-offset.c +++ b/posix/tst-mmap-offset.c @@ -1,4 +1,4 @@ -/* BZ #18877 and #21270 mmap offset test. +/* BZ #18877, BZ #21270, and BZ #24699 mmap offset test. Copyright (C) 2015-2019 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -24,6 +24,7 @@ #include <unistd.h> #include <errno.h> #include <sys/mman.h> +#include <mmap_info.h> #include <support/check.h> @@ -76,7 +77,7 @@ do_test_bz18877 (void) /* Check if invalid offset are handled correctly by mmap. */ static int -do_test_bz21270 (void) +do_test_large_offset (void) { /* For architectures with sizeof (off_t) < sizeof (off64_t) mmap is implemented with __SYS_mmap2 syscall and the offset is represented in @@ -90,7 +91,7 @@ do_test_bz21270 (void) const size_t length = 4096; void *addr = mmap64 (NULL, length, prot, flags, fd, offset); - if (sizeof (off_t) < sizeof (off64_t)) + if (mmap64_maximum_offset (page_shift) < UINT64_MAX) { if ((addr != MAP_FAILED) && (errno != EINVAL)) FAIL_RET ("mmap succeed"); @@ -110,7 +111,7 @@ do_test (void) int ret = 0; ret += do_test_bz18877 (); - ret += do_test_bz21270 (); + ret += do_test_large_offset (); return ret; } diff --git a/sysdeps/generic/mmap_info.h b/sysdeps/generic/mmap_info.h new file mode 100644 index 0000000000..b3087df2d3 --- /dev/null +++ b/sysdeps/generic/mmap_info.h @@ -0,0 +1,16 @@ +/* As default architectures with sizeof (off_t) < sizeof (off64_t) the mmap is + implemented with __SYS_mmap2 syscall and the offset is represented in + multiples of page size. For offset larger than + '1 << (page_shift + 8 * sizeof (off_t))' (that is, 1<<44 on system with + page size of 4096 bytes) the system call silently truncates the offset. + For this case, glibc mmap implementation returns EINVAL. */ + +/* Return the maximum value expected as offset argument in mmap64 call. */ +static inline uint64_t +mmap64_maximum_offset (long int page_shift) +{ + if (sizeof (off_t) < sizeof (off64_t)) + return (UINT64_C(1) << (page_shift + (8 * sizeof (off_t)))) - 1; + else + return UINT64_MAX; +} diff --git a/sysdeps/unix/sysv/linux/mips/mmap_info.h b/sysdeps/unix/sysv/linux/mips/mmap_info.h new file mode 100644 index 0000000000..07c9e3a044 --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/mmap_info.h @@ -0,0 +1,13 @@ +/* mips64n32 uses __NR_mmap for mmap64 while still having sizeof (off_t) + smaller than sizeof (off64_t). So it allows mapping large offsets + using mmap64 than 32-bit archs which uses __NR_mmap2. */ + +static inline uint64_t +mmap64_maximum_offset (long int page_shift) +{ +#if _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64 + return UINT64_MAX; +#else + return (UINT64_C(1) << (page_shift + (8 * sizeof (off_t)))) - 1; +#endif +} diff --git a/sysdeps/unix/sysv/linux/mmap64.c b/sysdeps/unix/sysv/linux/mmap64.c index cb56540119..671db2b654 100644 --- a/sysdeps/unix/sysv/linux/mmap64.c +++ b/sysdeps/unix/sysv/linux/mmap64.c @@ -23,11 +23,18 @@ #include <sysdep.h> #include <mmap_internal.h> +#ifdef __NR_mmap2 /* To avoid silent truncation of offset when using mmap2, do not accept offset larger than 1 << (page_shift + off_t bits). For archictures with 32 bits off_t and page size of 4096 it would be 1^44. */ -#define MMAP_OFF_HIGH_MASK \ +# define MMAP_OFF_HIGH_MASK \ ((-(MMAP2_PAGE_UNIT << 1) << (8 * sizeof (off_t) - 1))) +#else +/* Some ABIs might use __NR_mmap while having sizeof (off_t) smaller than + sizeof (off64_t) (currently only MIPS64n32). For this case just set + zero the higher bits so mmap with large offset does not fail. */ +# define MMAP_OFF_HIGH_MASK 0x0 +#endif #define MMAP_OFF_MASK (MMAP_OFF_HIGH_MASK | MMAP_OFF_LOW_MASK) |