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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-22 16:12:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-22 16:12:01 -0800
commit8456e98e18f35f4d4376e8ff3110a3342f81ce9b (patch)
treeb8772abf9ae7eb5d09f302abcdd9f946ba8487e5 /arch
parent77dc1181d896c5c3f8e131e341993aef41e16505 (diff)
parent71d73a0b43c2b101a960c624290c8a053d174cac (diff)
Merge branch 'parisc-5.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller: "Fix ptrace syscall number modification which has been broken since kernel v4.5 and provide alternative email addresses for the remaining users of the retired parisc-linux.org email domain" * 'parisc-5.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: CREDITS/MAINTAINERS: Retire parisc-linux.org email domain parisc: Fix ptrace syscall number modification
Diffstat (limited to 'arch')
-rw-r--r--arch/parisc/kernel/ptrace.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 2582df1c529b..0964c236e3e5 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -308,15 +308,29 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
long do_syscall_trace_enter(struct pt_regs *regs)
{
- if (test_thread_flag(TIF_SYSCALL_TRACE) &&
- tracehook_report_syscall_entry(regs)) {
+ if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+ int rc = tracehook_report_syscall_entry(regs);
+
/*
- * Tracing decided this syscall should not happen or the
- * debugger stored an invalid system call number. Skip
- * the system call and the system call restart handling.
+ * As tracesys_next does not set %r28 to -ENOSYS
+ * when %r20 is set to -1, initialize it here.
*/
- regs->gr[20] = -1UL;
- goto out;
+ regs->gr[28] = -ENOSYS;
+
+ if (rc) {
+ /*
+ * A nonzero return code from
+ * tracehook_report_syscall_entry() tells us
+ * to prevent the syscall execution. Skip
+ * the syscall call and the syscall restart handling.
+ *
+ * Note that the tracer may also just change
+ * regs->gr[20] to an invalid syscall number,
+ * that is handled by tracesys_next.
+ */
+ regs->gr[20] = -1UL;
+ return -1;
+ }
}
/* Do the secure computing check after ptrace. */
@@ -340,7 +354,6 @@ long do_syscall_trace_enter(struct pt_regs *regs)
regs->gr[24] & 0xffffffff,
regs->gr[23] & 0xffffffff);
-out:
/*
* Sign extend the syscall number to 64bit since it may have been
* modified by a compat ptrace call