s390/seccomp: add support for system call filtering using BPF
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 76de6b6..107610e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -124,6 +124,7 @@
select GENERIC_TIME_VSYSCALL
select GENERIC_CLOCKEVENTS
select KTIME_SCALAR if 32BIT
+ select HAVE_ARCH_SECCOMP_FILTER
config SCHED_OMIT_FRAME_POINTER
def_bool y
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index fb214dd..fe7b997 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -12,6 +12,7 @@
#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H 1
+#include <linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <asm/ptrace.h>
@@ -87,4 +88,13 @@
regs->orig_gpr2 = args[0];
}
+static inline int syscall_get_arch(struct task_struct *task,
+ struct pt_regs *regs)
+{
+#ifdef CONFIG_COMPAT
+ if (test_tsk_thread_flag(task, TIF_31BIT))
+ return AUDIT_ARCH_S390;
+#endif
+ return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;
+}
#endif /* _ASM_SYSCALL_H */
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index f4eb376..e4be113 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -719,7 +719,11 @@
long ret = 0;
/* Do the secure computing check first. */
- secure_computing_strict(regs->gprs[2]);
+ if (secure_computing(regs->gprs[2])) {
+ /* seccomp failures shouldn't expose any additional code. */
+ ret = -1;
+ goto out;
+ }
/*
* The sysc_tracesys code in entry.S stored the system
@@ -745,6 +749,7 @@
regs->gprs[2], regs->orig_gpr2,
regs->gprs[3], regs->gprs[4],
regs->gprs[5]);
+out:
return ret ?: regs->gprs[2];
}
