From 05005ae0fb3fe47123b7a370f6d43dc680cb313c Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Feb 2019 13:52:31 +0100
Subject: [PATCH] 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>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 02adcaf6ebea6..16f80a4488206 100644
--- 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;
--
2.39.5