diff options
author | Otavio Salvador <otavio@ossystems.com.br> | 2019-03-28 10:47:24 -0300 |
---|---|---|
committer | GitHub <noreply@github.com> | 2019-03-28 10:47:24 -0300 |
commit | 0a8ab17689e628c84a666195bfc6ab85d11cf057 (patch) | |
tree | 01630dc4a6935df99bf7d11d34ff8d384fed86e2 /arch/parisc/kernel/ptrace.c | |
parent | 1e71d8c630cbc0d1f5d762fd019690b5cdb880ae (diff) | |
parent | 32aca03c2ce868d3412da0bb6ce6798c7bea357e (diff) |
Merge pull request #46 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'arch/parisc/kernel/ptrace.c')
-rw-r--r-- | arch/parisc/kernel/ptrace.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index e02d7b4d2b69..0780c375fe2e 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -311,15 +311,29 @@ 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. */ @@ -343,7 +357,6 @@ 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 |