提交 f4d27817 编写于 作者: D David Woodhouse 提交者: Linus Torvalds

fix radeon setparam on 32/64 systems, harder.

Commit 9b01bd5b introduced a
compat_ioctl handler for RADEON_SETPARAM, the sole purpose of which was
to handle the fact that on i386, alignof(uint64_t)==4.

Unfortunately, this handler was installed for _all_ 64-bit
architectures, instead of only x86_64 and ia64.  And thus it breaks
32-bit compatibility on every other arch, where 64-bit integers are
aligned to 8 bytes in 32-bit mode just the same as in 64-bit mode.

Arnd has a cunning plan to use 'compat_u64' with appropriate alignment
attributes according to the 32-bit ABI, but for now let's just make the
compat_radeon_cp_setparam routine entirely disappear on 64-bit machines
whose 32-bit compat support isn't for i386.  It would be a no-op with
compat_u64 anyway.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 de7f928c
......@@ -349,6 +349,8 @@ static int compat_radeon_irq_emit(struct file *file, unsigned int cmd,
DRM_IOCTL_RADEON_IRQ_EMIT, (unsigned long)request);
}
/* The two 64-bit arches where alignof(u64)==4 in 32-bit code */
#if defined (CONFIG_X86_64) || defined(CONFIG_IA64)
typedef struct drm_radeon_setparam32 {
int param;
u64 value;
......@@ -373,6 +375,9 @@ static int compat_radeon_cp_setparam(struct file *file, unsigned int cmd,
return drm_ioctl(file->f_dentry->d_inode, file,
DRM_IOCTL_RADEON_SETPARAM, (unsigned long) request);
}
#else
#define compat_radeon_cp_setparam NULL
#endif /* X86_64 || IA64 */
drm_ioctl_compat_t *radeon_compat_ioctls[] = {
[DRM_RADEON_CP_INIT] = compat_radeon_cp_init,
......
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