summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/ptrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/ptrace.c')
-rw-r--r--arch/s390/kernel/ptrace.c83
1 files changed, 69 insertions, 14 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index ce60a459a143..3cc15c066298 100644
--- 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)