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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /arch/um/kernel/skas/syscall.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'arch/um/kernel/skas/syscall.c')
-rw-r--r--arch/um/kernel/skas/syscall.c31
1 files changed, 19 insertions, 12 deletions
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 1683b8efd..48b0dcbd8 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -5,31 +5,38 @@
#include <linux/kernel.h>
#include <linux/ptrace.h>
+#include <linux/seccomp.h>
#include <kern_util.h>
#include <sysdep/ptrace.h>
+#include <sysdep/ptrace_user.h>
#include <sysdep/syscalls.h>
-#include <os.h>
void handle_syscall(struct uml_pt_regs *r)
{
struct pt_regs *regs = container_of(r, struct pt_regs, regs);
- long result;
int syscall;
- if (syscall_trace_enter(regs)) {
- result = -ENOSYS;
+ /* Initialize the syscall number and default return value. */
+ UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
+ PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS);
+
+ /* Do the secure computing check first; failures should be fast. */
+ if (secure_computing() == -1)
+ return;
+
+ if (syscall_trace_enter(regs))
goto out;
- }
- syscall = get_syscall(r);
+ /* Update the syscall number after orig_ax has potentially been updated
+ * with ptrace.
+ */
+ UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
+ syscall = UPT_SYSCALL_NR(r);
- if ((syscall > __NR_syscall_max) || syscall < 0)
- result = -ENOSYS;
- else
- result = EXECUTE_SYSCALL(syscall, regs);
+ if (syscall >= 0 && syscall <= __NR_syscall_max)
+ PT_REGS_SET_SYSCALL_RETURN(regs,
+ EXECUTE_SYSCALL(syscall, regs));
out:
- PT_REGS_SET_SYSCALL_RETURN(regs, result);
-
syscall_trace_leave(regs);
}