i915, uaccess: Fix redundant CLAC

New tooling noticed this:

 drivers/gpu/drm/i915/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x3c: redundant UACCESS disable
 drivers/gpu/drm/i915/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x66: redundant UACCESS disable

You don't need user_access_end() if user_access_begin() fails.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 02adcaf..16f80a4 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1667,6 +1667,7 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb)
                                             len)) {
 end_user:
                                user_access_end();
+end:
                                kvfree(relocs);
                                err = -EFAULT;
                                goto err;
@@ -1686,7 +1687,7 @@ end_user:
                 * relocations were valid.
                 */
                if (!user_access_begin(urelocs, size))
-                       goto end_user;
+                       goto end;
 
                for (copied = 0; copied < nreloc; copied++)
                        unsafe_put_user(-1,
@@ -2695,7 +2696,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
                 * when we did the "copy_from_user()" above.
                 */
                if (!user_access_begin(user_exec_list, count * sizeof(*user_exec_list)))
-                       goto end_user;
+                       goto end;
 
                for (i = 0; i < args->buffer_count; i++) {
                        if (!(exec2_list[i].offset & UPDATE))
@@ -2709,6 +2710,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
                }
 end_user:
                user_access_end();
+end:;
        }
 
        args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;