[PATCH v1 1/4] um: Fix ptrace GETREGS/SETREGS bugs
From: Mickaël Salaün <mic@digikod.net>
Date: 2015-12-21 00:18:06
Also in:
linux-um, lkml
Subsystem:
the rest, user-mode linux (uml) · Maintainers:
Linus Torvalds, Richard Weinberger, Anton Ivanov, Johannes Berg
This fix two related bugs: * PTRACE_GETREGS doesn't get the right orig_ax (syscall) value * PTRACE_SETREGS can't set the orig_ax value (erased by initial value) Remove the now useless and error-prone get_syscall(). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <redacted> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <redacted> Cc: Kees Cook <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Thomas Meyer <redacted> Cc: Nicolas Iooss <redacted> Cc: Anton Ivanov <redacted> Cc: linux-kernel@vger.kernel.org Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Cc: Meredydd Luff <redacted> Cc: David Drysdale <redacted> --- arch/um/kernel/skas/syscall.c | 7 ++++++- arch/um/os-Linux/skas/process.c | 7 ------- 2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 1683b8e..65f0d1a 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c@@ -7,6 +7,7 @@ #include <linux/ptrace.h> #include <kern_util.h> #include <sysdep/ptrace.h> +#include <sysdep/ptrace_user.h> #include <sysdep/syscalls.h> #include <os.h>
@@ -16,12 +17,16 @@ void handle_syscall(struct uml_pt_regs *r) long result; int syscall; + /* Save the syscall register. */ + UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp); + if (syscall_trace_enter(regs)) { result = -ENOSYS; goto out; } - syscall = get_syscall(r); + /* Get the syscall after being potentially updated with ptrace. */ + syscall = UPT_SYSCALL_NR(r); if ((syscall > __NR_syscall_max) || syscall < 0) result = -ENOSYS;
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index b856c66..23025d6 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c@@ -172,13 +172,6 @@ static void handle_trap(int pid, struct uml_pt_regs *regs, handle_syscall(regs); } -int get_syscall(struct uml_pt_regs *regs) -{ - UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); - - return UPT_SYSCALL_NR(regs); -} - extern char __syscall_stub_start[]; static int userspace_tramp(void *stack)
--
2.6.4