Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux-2.6-microblaze.git] / arch / s390 / kernel / ptrace.c

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 367a687..a09b9e9 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -323,6 +323,25 @@ static inline void __poke_user_per(struct task_struct *child,
                child->thread.per_user.end = data;
 }
 
+static void fixup_int_code(struct task_struct *child, addr_t data)
+{
+       struct pt_regs *regs = task_pt_regs(child);
+       int ilc = regs->int_code >> 16;
+       u16 insn;
+
+       if (ilc > 6)
+               return;
+
+       if (ptrace_access_vm(child, regs->psw.addr - (regs->int_code >> 16),
+                       &insn, sizeof(insn), FOLL_FORCE) != sizeof(insn))
+               return;
+
+       /* double check that tracee stopped on svc instruction */
+       if ((insn >> 8) != 0xa)
+               return;
+
+       regs->int_code = 0x20000 | (data & 0xffff);
+}
 /*
  * Write a word to the user area of a process at location addr. This
  * operation does have an additional problem compared to peek_user.
@@ -334,7 +353,9 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
        struct user *dummy = NULL;
        addr_t offset;
 
+
        if (addr < (addr_t) &dummy->regs.acrs) {
+               struct pt_regs *regs = task_pt_regs(child);
                /*
                 * psw and gprs are stored on the stack
                 */
@@ -352,7 +373,11 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
                                /* Invalid addressing mode bits */
                                return -EINVAL;
                }
-               *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
+
+               if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
+                       addr == offsetof(struct user, regs.gprs[2]))
+                       fixup_int_code(child, data);
+               *(addr_t *)((addr_t) &regs->psw + addr) = data;
 
        } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
                /*
@@ -718,6 +743,10 @@ static int __poke_user_compat(struct task_struct *child,
                        regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
                                (__u64)(tmp & PSW32_ADDR_AMODE);
                } else {
+
+                       if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
+                               addr == offsetof(struct compat_user, regs.gprs[2]))
+                               fixup_int_code(child, data);
                        /* gpr 0-15 */
                        *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
                }
@@ -837,40 +866,66 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
        unsigned long mask = -1UL;
+       long ret = -1;
+
+       if (is_compat_task())
+               mask = 0xffffffff;
 
        /*
         * The sysc_tracesys code in entry.S stored the system
         * call number to gprs[2].
         */
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-           (tracehook_report_syscall_entry(regs) ||
-            regs->gprs[2] >= NR_syscalls)) {
+           tracehook_report_syscall_entry(regs)) {
                /*
-                * Tracing decided this syscall should not happen or the
-                * debugger stored an invalid system call number. Skip
+                * Tracing decided this syscall should not happen. Skip
                 * the system call and the system call restart handling.
                 */
-               clear_pt_regs_flag(regs, PIF_SYSCALL);
-               return -1;
+               goto skip;
        }
 
+#ifdef CONFIG_SECCOMP
        /* Do the secure computing check after ptrace. */
-       if (secure_computing()) {
-               /* seccomp failures shouldn't expose any additional code. */
-               return -1;
+       if (unlikely(test_thread_flag(TIF_SECCOMP))) {
+               struct seccomp_data sd;
+
+               if (is_compat_task()) {
+                       sd.instruction_pointer = regs->psw.addr & 0x7fffffff;
+                       sd.arch = AUDIT_ARCH_S390;
+               } else {
+                       sd.instruction_pointer = regs->psw.addr;
+                       sd.arch = AUDIT_ARCH_S390X;
+               }
+
+               sd.nr = regs->int_code & 0xffff;
+               sd.args[0] = regs->orig_gpr2 & mask;
+               sd.args[1] = regs->gprs[3] & mask;
+               sd.args[2] = regs->gprs[4] & mask;
+               sd.args[3] = regs->gprs[5] & mask;
+               sd.args[4] = regs->gprs[6] & mask;
+               sd.args[5] = regs->gprs[7] & mask;
+
+               if (__secure_computing(&sd) == -1)
+                       goto skip;
        }
+#endif /* CONFIG_SECCOMP */
 
        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
-               trace_sys_enter(regs, regs->gprs[2]);
+               trace_sys_enter(regs, regs->int_code & 0xffff);
 
-       if (is_compat_task())
-               mask = 0xffffffff;
 
-       audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
+       audit_syscall_entry(regs->int_code & 0xffff, regs->orig_gpr2 & mask,
                            regs->gprs[3] &mask, regs->gprs[4] &mask,
                            regs->gprs[5] &mask);
 
+       if ((signed long)regs->gprs[2] >= NR_syscalls) {
+               regs->gprs[2] = -ENOSYS;
+               ret = -ENOSYS;
+       }
        return regs->gprs[2];
+skip:
+       clear_pt_regs_flag(regs, PIF_SYSCALL);
+       return ret;
 }
 
 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)