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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/um/bugs_32.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/um/bugs_32.c')
-rw-r--r--kernel/arch/x86/um/bugs_32.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/kernel/arch/x86/um/bugs_32.c b/kernel/arch/x86/um/bugs_32.c
new file mode 100644
index 000000000..33daff4da
--- /dev/null
+++ b/kernel/arch/x86/um/bugs_32.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <signal.h>
+#include <kern_util.h>
+#include <longjmp.h>
+#include <sysdep/ptrace.h>
+#include <generated/asm-offsets.h>
+
+/* Set during early boot */
+static int host_has_cmov = 1;
+static jmp_buf cmov_test_return;
+
+static void cmov_sigill_test_handler(int sig)
+{
+ host_has_cmov = 0;
+ longjmp(cmov_test_return, 1);
+}
+
+void arch_check_bugs(void)
+{
+ struct sigaction old, new;
+
+ printk(UM_KERN_INFO "Checking for host processor cmov support...");
+ new.sa_handler = cmov_sigill_test_handler;
+
+ /* Make sure that SIGILL is enabled after the handler longjmps back */
+ new.sa_flags = SA_NODEFER;
+ sigemptyset(&new.sa_mask);
+ sigaction(SIGILL, &new, &old);
+
+ if (setjmp(cmov_test_return) == 0) {
+ unsigned long foo = 0;
+ __asm__ __volatile__("cmovz %0, %1" : "=r" (foo) : "0" (foo));
+ printk(UM_KERN_CONT "Yes\n");
+ } else
+ printk(UM_KERN_CONT "No\n");
+
+ sigaction(SIGILL, &old, &new);
+}
+
+void arch_examine_signal(int sig, struct uml_pt_regs *regs)
+{
+ unsigned char tmp[2];
+
+ /*
+ * This is testing for a cmov (0x0f 0x4x) instruction causing a
+ * SIGILL in init.
+ */
+ if ((sig != SIGILL) || (get_current_pid() != 1))
+ return;
+
+ if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2)) {
+ printk(UM_KERN_ERR "SIGILL in init, could not read "
+ "instructions!\n");
+ return;
+ }
+
+ if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
+ return;
+
+ if (host_has_cmov == 0)
+ printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+ "processor doesn't implement. Boot a filesystem "
+ "compiled for older processors");
+ else if (host_has_cmov == 1)
+ printk(UM_KERN_ERR "SIGILL caused by cmov, which this "
+ "processor claims to implement");
+ else
+ printk(UM_KERN_ERR "Bad value for host_has_cmov (%d)",
+ host_has_cmov);
+}