lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sat,  9 May 2020 19:05:36 +0800
From:   Xiaoyao Li <>
To:     Paolo Bonzini <>,
        Thomas Gleixner <>,
        Sean Christopherson <>,
        Ingo Molnar <>, Borislav Petkov <>,
        "H. Peter Anvin" <>,
        Andy Lutomirski <>,,
        Arvind Sankar <>,
        Tony Luck <>,
        Fenghua Yu <>,
        Xiaoyao Li <>
Subject: [PATCH v9 2/8] x86/split_lock: Remove bogus case in handle_guest_split_lock()

The bogus case can never happen, i.e., when sld_state == sld_off, guest
won't trigger split lock #AC and of course no handle_guest_split_lock()
will be called.

Beside, drop bogus case also makes future patch easier to remove
sld_state if we reach the alignment that it must be sld_warn or
sld_fatal when handle_guest_split_lock() is called.

Signed-off-by: Xiaoyao Li <>
  The alternative would be to remove the "SLD enabled" check from KVM so
  that a truly unexpected/bogus #AC would generate a warn.  It's not clear
  whether or not calling handle_guest_split_lock() iff SLD is enabled was
  intended in the long term.
 arch/x86/kernel/cpu/intel.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 0e6aee6ef1e8..4602dac14dcb 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1088,9 +1088,8 @@ bool handle_guest_split_lock(unsigned long ip)
 		return true;
-	pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
-		     current->comm, current->pid,
-		     sld_state == sld_fatal ? "fatal" : "bogus", ip);
+	pr_warn_once("#AC: %s/%d fatal split_lock trap at address: 0x%lx\n",
+		     current->comm, current->pid, ip);
 	current->thread.error_code = 0;
 	current->thread.trap_nr = X86_TRAP_AC;

Powered by blists - more mailing lists