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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-06-18 14:09:09 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-07-10 16:52:50 -0300 |
| commit | a008c76b56e4f958cf5a0d6f67d29fade89421b7 (patch) | |
| tree | c3f73587250f781b2c298d10762b14e09032b6b3 /sysdeps/unix/sysv | |
| parent | 99135114ba23c3110b7e4e650fabdc5e639746b7 (diff) | |
| download | glibc-a008c76b56e4f958cf5a0d6f67d29fade89421b7.tar.gz | |
posix: Fix large mmap64 offset for mips64n32 (BZ#24699)
The fix for BZ#21270 (commit 158d5fa0e19) added a mask to avoid offset larger
than 1^44 to be used along __NR_mmap2. However mips64n32 users __NR_mmap,
as mips64n64, but still defines off_t as old non-LFS type (other ILP32, such
x32, defines off_t being equal to off64_t). This leads to use the same
mask meant only for __NR_mmap2 call for __NR_mmap, thus limiting the maximum
offset it can use with mmap64.
This patch fixes by setting the high mask only for __NR_mmap2 usage. The
posix/tst-mmap-offset.c already tests it and also fails for mips64n32. The
patch also change the test to check for an arch-specific header that defines
the maximum supported offset.
Checked on x86_64-linux-gnu, i686-linux-gnu, and I also tests tst-mmap-offset
on qemu simulated mips64 with kernel 3.2.0 kernel for both mips-linux-gnu and
mips64-n32-linux-gnu.
[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.
Diffstat (limited to 'sysdeps/unix/sysv')
| -rw-r--r-- | sysdeps/unix/sysv/linux/mips/mmap_info.h | 13 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/mmap64.c | 9 |
2 files changed, 21 insertions, 1 deletions
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) |