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From:   joao@overdrivepizza.com
To:     linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Cc:     joao@overdrivepizza.com, peterz@infradead.org, jpoimboe@redhat.com,
        andrew.cooper3@citrix.com, keescook@chromium.org,
        samitolvanen@google.com, mark.rutland@arm.com, hjl.tools@gmail.com,
        alyssa.milburn@linux.intel.com, ndesaulniers@google.com,
        gabriel.gomes@linux.intel.com, rick.p.edgecombe@intel.com
Subject: [RFC PATCH 07/11] x86/lib: Prevent UACCESS call warning from objtool
Date:   Tue, 19 Apr 2022 17:42:37 -0700
Message-Id: <20220420004241.2093-8-joao@overdrivepizza.com>
In-Reply-To: <20220420004241.2093-1-joao@overdrivepizza.com>
References: <20220420004241.2093-1-joao@overdrivepizza.com>
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From: Joao Moreira <joao@overdrivepizza.com>

Objtool emits a warning whenever it finds a call that may happen with
UACCESS enabled. Prevent this b not emitting calls to the
__fineibt_handler in such circumstances, making the function
coarse-grained.

Signed-off-by: Joao Moreira <joao@overdrivepizza.com>
---
 arch/x86/lib/copy_mc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c
index 80efd45a7761..554e6c6ecea2 100644
--- a/arch/x86/lib/copy_mc.c
+++ b/arch/x86/lib/copy_mc.c
@@ -22,7 +22,7 @@ void enable_copy_mc_fragile(void)
  * Similar to copy_user_handle_tail, probe for the write fault point, or
  * source exception point.
  */
-__visible notrace unsigned long
+__visible notrace unsigned long __coarseendbr
 copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
 {
 	for (; len; --len, to++, from++)
-- 
2.35.1