From 910cd32e552ea09caa89cdbe328e468979b030dd Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 30 Mar 2016 14:14:31 +0200 Subject: parisc: Fix and enable seccomp filter support The seccomp filter support requires careful handling of task registers. This includes reloading of the return value (%r28) and proper syscall exit if secure_computing() returned -1. Additionally we need to sign-extend the syscall number from signed 32bit to signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows storing 32bit values in compat mode. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v4.5 --- arch/parisc/kernel/ptrace.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'arch/parisc/kernel/ptrace.c') diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index ce0b2b4075c7..8fb81a391599 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -270,7 +270,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, long do_syscall_trace_enter(struct pt_regs *regs) { /* Do the secure computing check first. */ - secure_computing_strict(regs->gr[20]); + if (secure_computing() == -1) + return -1; if (test_thread_flag(TIF_SYSCALL_TRACE) && tracehook_report_syscall_entry(regs)) { @@ -296,7 +297,11 @@ long do_syscall_trace_enter(struct pt_regs *regs) regs->gr[23] & 0xffffffff); out: - return regs->gr[20]; + /* + * Sign extend the syscall number to 64bit since it may have been + * modified by a compat ptrace call + */ + return (int) ((u32) regs->gr[20]); } void do_syscall_trace_exit(struct pt_regs *regs) -- cgit v1.2.1