5.4-stable patches

added patches:
	x86-drop-bogus-cc-clobber-from-__try_cmpxchg_user_asm.patch

diff --git a/queue-5.4/series b/queue-5.4/series
index 761bd574f85e558575ca9546bf9cf28fe158ff2f..c4979baf908c90fe166fafae6d3d3bc2f2a4d978 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -84,3 +84,4 @@ tty-drop-tty_schedule_flip.patch
 tty-extract-tty_flip_buffer_commit-from-tty_flip_buffer_push.patch
 tty-use-new-tty_insert_flip_string_and_push_buffer-in-pty_write.patch
 net-usb-ax88179_178a-needs-flag_send_zlp.patch
+x86-drop-bogus-cc-clobber-from-__try_cmpxchg_user_asm.patch

diff --git a/queue-5.4/x86-drop-bogus-cc-clobber-from-__try_cmpxchg_user_asm.patch b/queue-5.4/x86-drop-bogus-cc-clobber-from-__try_cmpxchg_user_asm.patch
new file mode 100644 (file)
index 0000000..dcba8a0
--- /dev/null
+++ b/queue-5.4/x86-drop-bogus-cc-clobber-from-__try_cmpxchg_user_asm.patch
@@ -0,0 +1,36 @@
+From 1df931d95f4dc1c11db1123e85d4e08156e46ef9 Mon Sep 17 00:00:00 2001
+From: Jan Beulich <jbeulich@suse.com>
+Date: Tue, 7 Jun 2022 17:00:53 +0200
+Subject: x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm()
+
+From: Jan Beulich <jbeulich@suse.com>
+
+commit 1df931d95f4dc1c11db1123e85d4e08156e46ef9 upstream.
+
+As noted (and fixed) a couple of times in the past, "=@cc<cond>" outputs
+and clobbering of "cc" don't work well together. The compiler appears to
+mean to reject such, but doesn't - in its upstream form - quite manage
+to yet for "cc". Furthermore two similar macros don't clobber "cc", and
+clobbering "cc" is pointless in asm()-s for x86 anyway - the compiler
+always assumes status flags to be clobbered there.
+
+Fixes: 989b5db215a2 ("x86/uaccess: Implement macros for CMPXCHG on user addresses")
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Message-Id: <485c0c0b-a3a7-0b7c-5264-7d00c01de032@suse.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/uaccess.h |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/x86/include/asm/uaccess.h
++++ b/arch/x86/include/asm/uaccess.h
+@@ -498,7 +498,7 @@ __pu_label:                                                        \
+                      [ptr] "+m" (*_ptr),                              \
+                      [old] "+a" (__old)                               \
+                    : [new] ltype (__new)                              \
+-                   : "memory", "cc");                                 \
++                   : "memory");                                       \
+       if (unlikely(__err))                                            \
+               goto label;                                             \
+       if (unlikely(!success))                                         \