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author | Vladimir Murzin <vladimir.murzin@arm.com> | 2014-12-01 10:53:08 +0000 |
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committer | Will Deacon <will.deacon@arm.com> | 2014-12-01 13:31:12 +0000 |
commit | a2d25a5391ca219f196f9fee7b535c40d201c6bf (patch) | |
tree | 4b2e208ebac21cf53793db6ba4ed5a74b04a6d59 /arch/arm64/kernel/sys_compat.c | |
parent | a1ae65b219416a72c15577bd4c8c11174fffbb8b (diff) | |
download | linux-stable-a2d25a5391ca219f196f9fee7b535c40d201c6bf.tar.gz linux-stable-a2d25a5391ca219f196f9fee7b535c40d201c6bf.tar.bz2 linux-stable-a2d25a5391ca219f196f9fee7b535c40d201c6bf.zip |
arm64: compat: align cacheflush syscall with arch/arm
Update handling of cacheflush syscall with changes made in arch/arm
counterpart:
- return error to userspace when flushing syscall fails
- split user cache-flushing into interruptible chunks
- don't bother rounding to nearest vma
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
[will: changed internal return value from -EINTR to 0 to match arch/arm/]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/sys_compat.c')
-rw-r--r-- | arch/arm64/kernel/sys_compat.c | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c index dc47e53e9e28..28c511b06edf 100644 --- a/arch/arm64/kernel/sys_compat.c +++ b/arch/arm64/kernel/sys_compat.c @@ -28,29 +28,39 @@ #include <asm/cacheflush.h> #include <asm/unistd.h> -static inline void -do_compat_cache_op(unsigned long start, unsigned long end, int flags) +static long +__do_compat_cache_op(unsigned long start, unsigned long end) { - struct mm_struct *mm = current->active_mm; - struct vm_area_struct *vma; + long ret; - if (end < start || flags) - return; + do { + unsigned long chunk = min(PAGE_SIZE, end - start); - down_read(&mm->mmap_sem); - vma = find_vma(mm, start); - if (vma && vma->vm_start < end) { - if (start < vma->vm_start) - start = vma->vm_start; - if (end > vma->vm_end) - end = vma->vm_end; - up_read(&mm->mmap_sem); - __flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end)); - return; - } - up_read(&mm->mmap_sem); + if (fatal_signal_pending(current)) + return 0; + + ret = __flush_cache_user_range(start, start + chunk); + if (ret) + return ret; + + cond_resched(); + start += chunk; + } while (start < end); + + return 0; } +static inline long +do_compat_cache_op(unsigned long start, unsigned long end, int flags) +{ + if (end < start || flags) + return -EINVAL; + + if (!access_ok(VERIFY_READ, start, end - start)) + return -EFAULT; + + return __do_compat_cache_op(start, end); +} /* * Handle all unrecognised system calls. */ @@ -74,8 +84,7 @@ long compat_arm_syscall(struct pt_regs *regs) * the specified region). */ case __ARM_NR_compat_cacheflush: - do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]); - return 0; + return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]); case __ARM_NR_compat_set_tls: current->thread.tp_value = regs->regs[0]; |