diff options
| author | Chris Metcalf <cmetcalf@tilera.com> | 2013-03-04 11:19:09 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-14 11:26:25 -0700 |
| commit | 04825f04ac5042a966865ecc8fd6359fe59fa883 (patch) | |
| tree | 330b9c3b5f3310f9a32740724be6d651a1fdf756 /arch | |
| parent | 6474cd4cf32ac9edf960903db0f7b9955618ae4a (diff) | |
tile: work around bug in the generic sys_llseek
commit 5a114b98661e3aaa0ac085eb931584dce3b0ef9b upstream.
sys_llseek should specify the high and low 32-bit seek values as "unsigned
int" but instead it specifies "unsigned long". Since compat syscall
arguments are always sign-extended on tile, this means that a seek value
of 0xffffffff will be incorrectly interpreted as a value of -1ULL.
To avoid the risk of breaking binary compatibility on architectures
that already use sys_llseek this way, we follow the same path as MIPS
and provide a wrapper override.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/tile/include/asm/compat.h | 3 | ||||
| -rw-r--r-- | arch/tile/kernel/compat.c | 13 |
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h index 88f3c227afd9..59e35747c182 100644 --- a/arch/tile/include/asm/compat.h +++ b/arch/tile/include/asm/compat.h @@ -296,6 +296,9 @@ long compat_sys_sync_file_range2(int fd, unsigned int flags, long compat_sys_fallocate(int fd, int mode, u32 offset_lo, u32 offset_hi, u32 len_lo, u32 len_hi); +long compat_sys_llseek(unsigned int fd, unsigned int offset_high, + unsigned int offset_low, loff_t __user * result, + unsigned int origin); /* Assembly trampoline to avoid clobbering r0. */ long _compat_sys_rt_sigreturn(void); diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c index 7f72401b4f45..d8e3b7ea60ed 100644 --- a/arch/tile/kernel/compat.c +++ b/arch/tile/kernel/compat.c @@ -76,6 +76,18 @@ long compat_sys_fallocate(int fd, int mode, ((loff_t)len_hi << 32) | len_lo); } +/* + * Avoid bug in generic sys_llseek() that specifies offset_high and + * offset_low as "unsigned long", thus making it possible to pass + * a sign-extended high 32 bits in offset_low. + */ +long compat_sys_llseek(unsigned int fd, unsigned int offset_high, + unsigned int offset_low, loff_t __user * result, + unsigned int origin) +{ + return sys_llseek(fd, offset_high, offset_low, result, origin); +} + /* Provide the compat syscall number to call mapping. */ #undef __SYSCALL #define __SYSCALL(nr, call) [nr] = (call), @@ -83,6 +95,7 @@ long compat_sys_fallocate(int fd, int mode, /* See comments in sys.c */ #define compat_sys_fadvise64_64 sys32_fadvise64_64 #define compat_sys_readahead sys32_readahead +#define sys_llseek compat_sys_llseek /* Call the assembly trampolines where necessary. */ #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn |