1 files changed, 60 insertions, 9 deletions

diff --git a/arch/s390/kernel/uprobes.c b/arch/s390/kernel/uprobes.c
index f6b3cd056ec2..cc7328080b60 100644
--- a/arch/s390/kernel/uprobes.c
+++ b/arch/s390/kernel/uprobes.c
@@ -48,6 +48,30 @@ bool arch_uprobe_xol_was_trapped(struct task_struct *tsk)
         return false;
 }
 
+static int check_per_event(unsigned short cause, unsigned long control,
+                           struct pt_regs *regs)
+{
+        if (!(regs->psw.mask & PSW_MASK_PER))
+                return 0;
+        /* user space single step */
+        if (control == 0)
+                return 1;
+        /* over indication for storage alteration */
+        if ((control & 0x20200000) && (cause & 0x2000))
+                return 1;
+        if (cause & 0x8000) {
+                /* all branches */
+                if ((control & 0x80800000) == 0x80000000)
+                        return 1;
+                /* branch into selected range */
+                if (((control & 0x80800000) == 0x80800000) &&
+                    regs->psw.addr >= current->thread.per_user.start &&
+                    regs->psw.addr <= current->thread.per_user.end)
+                        return 1;
+        }
+        return 0;
+}
+
 int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
 {
         int fixup = probe_get_fixup_type(auprobe->insn);
@@ -71,9 +95,13 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
                 if (regs->psw.addr - utask->xol_vaddr == ilen)
                         regs->psw.addr = utask->vaddr + ilen;
         }
-        /* If per tracing was active generate trap */
-        if (regs->psw.mask & PSW_MASK_PER)
-                do_per_trap(regs);
+        if (check_per_event(current->thread.per_event.cause,
+                            current->thread.per_user.control, regs)) {
+                /* fix per address */
+                current->thread.per_event.address = utask->vaddr;
+                /* trigger per event */
+                set_pt_regs_flag(regs, PIF_PER_TRAP);
+        }
         return 0;
 }
 
@@ -106,6 +134,7 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
         clear_thread_flag(TIF_UPROBE_SINGLESTEP);
         regs->int_code = auprobe->saved_int_code;
         regs->psw.addr = current->utask->vaddr;
+        current->thread.per_event.address = current->utask->vaddr;
 }
 
 unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline,
@@ -146,17 +175,20 @@ static void adjust_psw_addr(psw_t *psw, unsigned long len)
         __rc;                                           \
 })
 
-#define emu_store_ril(ptr, input)                       \
+#define emu_store_ril(regs, ptr, input)                 \
 ({                                                      \
         unsigned int mask = sizeof(*(ptr)) - 1;         \
+        __typeof__(ptr) __ptr = (ptr);                  \
         int __rc = 0;                                   \
                                                         \
         if (!test_facility(34))                         \
                 __rc = EMU_ILLEGAL_OP;                  \
-        else if ((u64 __force)ptr & mask)               \
+        else if ((u64 __force)__ptr & mask)             \
                 __rc = EMU_SPECIFICATION;               \
-        else if (put_user(*(input), ptr))               \
+        else if (put_user(*(input), __ptr))             \
                 __rc = EMU_ADDRESSING;                  \
+        if (__rc == 0)                                  \
+                sim_stor_event(regs, __ptr, mask + 1);  \
         __rc;                                           \
 })
 
@@ -198,6 +230,25 @@ union split_register {
 };
 
 /*
+ * If user per registers are setup to trace storage alterations and an
+ * emulated store took place on a fitting address a user trap is generated.
+ */
+static void sim_stor_event(struct pt_regs *regs, void *addr, int len)
+{
+        if (!(regs->psw.mask & PSW_MASK_PER))
+                return;
+        if (!(current->thread.per_user.control & PER_EVENT_STORE))
+                return;
+        if ((void *)current->thread.per_user.start > (addr + len))
+                return;
+        if ((void *)current->thread.per_user.end < addr)
+                return;
+        current->thread.per_event.address = regs->psw.addr;
+        current->thread.per_event.cause = PER_EVENT_STORE >> 16;
+        set_pt_regs_flag(regs, PIF_PER_TRAP);
+}
+
+/*
  * pc relative instructions are emulated, since parameters may not be
  * accessible from the xol area due to range limitations.
  */
@@ -249,13 +300,13 @@ static void handle_insn_ril(struct arch_uprobe *auprobe, struct pt_regs *regs)
                         rc = emu_load_ril((u32 __user *)uptr, &rx->u64);
                         break;
                 case 0x07: /* sthrl */
-                        rc = emu_store_ril((u16 __user *)uptr, &rx->u16[3]);
+                        rc = emu_store_ril(regs, (u16 __user *)uptr, &rx->u16[3]);
                         break;
                 case 0x0b: /* stgrl */
-                        rc = emu_store_ril((u64 __user *)uptr, &rx->u64);
+                        rc = emu_store_ril(regs, (u64 __user *)uptr, &rx->u64);
                         break;
                 case 0x0f: /* strl */
-                        rc = emu_store_ril((u32 __user *)uptr, &rx->u32[1]);
+                        rc = emu_store_ril(regs, (u32 __user *)uptr, &rx->u32[1]);
                         break;
                 }
                 break;