s390/uprobes: architecture backend for uprobes

Signed-off-by: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 22 insertions, 11 deletions

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index c5762324d9ee..e3e06a4fdfce 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -58,15 +58,10 @@ int is_valid_bugaddr(unsigned long addr)
         return 1;
 }
 
-static void __kprobes do_trap(struct pt_regs *regs,
-                              int si_signo, int si_code, char *str)
+void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
 {
         siginfo_t info;
 
-        if (notify_die(DIE_TRAP, str, regs, 0,
-                       regs->int_code, si_signo) == NOTIFY_STOP)
-                return;
-
         if (user_mode(regs)) {
                 info.si_signo = si_signo;
                 info.si_errno = 0;
@@ -90,6 +85,15 @@ static void __kprobes do_trap(struct pt_regs *regs,
         }
 }
 
+static void __kprobes do_trap(struct pt_regs *regs, int si_signo, int si_code,
+                              char *str)
+{
+        if (notify_die(DIE_TRAP, str, regs, 0,
+                       regs->int_code, si_signo) == NOTIFY_STOP)
+                return;
+        do_report_trap(regs, si_signo, si_code, str);
+}
+
 void __kprobes do_per_trap(struct pt_regs *regs)
 {
         siginfo_t info;
@@ -178,6 +182,7 @@ void __kprobes illegal_op(struct pt_regs *regs)
         siginfo_t info;
         __u8 opcode[6];
         __u16 __user *location;
+        int is_uprobe_insn = 0;
         int signal = 0;
 
         location = get_trap_ip(regs);
@@ -194,6 +199,10 @@ void __kprobes illegal_op(struct pt_regs *regs)
                                 force_sig_info(SIGTRAP, &info, current);
                         } else
                                 signal = SIGILL;
+#ifdef CONFIG_UPROBES
+                } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
+                        is_uprobe_insn = 1;
+#endif
 #ifdef CONFIG_MATHEMU
                 } else if (opcode[0] == 0xb3) {
                         if (get_user(*((__u16 *) (opcode+2)), location+1))
@@ -219,11 +228,13 @@ void __kprobes illegal_op(struct pt_regs *regs)
 #endif
                 } else
                         signal = SIGILL;
-        } else {
-                /*
-                 * If we get an illegal op in kernel mode, send it through the
-                 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
-                 */
+        }
+        /*
+         * We got either an illegal op in kernel mode, or user space trapped
+         * on a uprobes illegal instruction. See if kprobes or uprobes picks
+         * it up. If not, SIGILL.
+         */
+        if (is_uprobe_insn || !user_mode(regs)) {
                 if (notify_die(DIE_BPT, "bpt", regs, 0,
                                3, SIGTRAP) != NOTIFY_STOP)
                         signal = SIGILL;