#include <asm/uaccess.h>
#include <asm/unaligned.h>
-extern void die_if_kernel(char *str, struct pt_regs *regs, long err) __attribute__ ((noreturn));
+extern void die_if_kernel(char *str, struct pt_regs *regs, long err);
#undef DEBUG_UNALIGNED_TRAP
#define IA64_FIRST_ROTATING_FR 32
#define SIGN_EXT9 0xffffffffffffff00ul
+/*
+ * sysctl settable hook which tells the kernel whether to honor the
+ * IA64_THREAD_UAC_NOPRINT prctl. Because this is user settable, we want
+ * to allow the super user to enable/disable this for security reasons
+ * (i.e. don't allow attacker to fill up logs with unaligned accesses).
+ */
+int no_unaligned_warning;
+static int noprint_warning;
+
/*
* For M-unit:
*
if ((current->thread.flags & IA64_THREAD_UAC_SIGBUS) != 0)
goto force_sigbus;
- if (!(current->thread.flags & IA64_THREAD_UAC_NOPRINT)
- && within_logging_rate_limit())
+ if (!no_unaligned_warning &&
+ !(current->thread.flags & IA64_THREAD_UAC_NOPRINT) &&
+ within_logging_rate_limit())
{
char buf[200]; /* comm[] is at most 16 bytes... */
size_t len;
if (user_mode(regs))
tty_write_message(current->signal->tty, buf);
buf[len-1] = '\0'; /* drop '\r' */
- printk(KERN_WARNING "%s", buf); /* watch for command names containing %s */
+ /* watch for command names containing %s */
+ printk(KERN_WARNING "%s", buf);
+ } else {
+ if (no_unaligned_warning && !noprint_warning) {
+ noprint_warning = 1;
+ printk(KERN_WARNING "%s(%d) encountered an "
+ "unaligned exception which required\n"
+ "kernel assistance, which degrades "
+ "the performance of the application.\n"
+ "Unaligned exception warnings have "
+ "been disabled by the system "
+ "administrator\n"
+ "echo 0 > /proc/sys/kernel/ignore-"
+ "unaligned-usertrap to re-enable\n",
+ current->comm, current->pid);
+ }
}
} else {
if (within_logging_rate_limit())