From: Thomas Meyer <thomas@m3y3r.de>
Date: Wed, 5 Jul 2017 22:31:14 +0000 (+0200)
Subject: um: userspace - be more verbose in ptrace set regs error
X-Git-Tag: v4.13-rc1~8^2~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=22e19c8d062cc19832cde13225cbc6e5283cd969;p=thirdparty%2Fkernel%2Flinux.git

um: userspace - be more verbose in ptrace set regs error

When ptrace fails to set GP/FP regs for the target process,
log the error before crashing the UML kernel.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
---

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 03b3c4cc7735a..31c9be2c2bddf 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -323,11 +323,17 @@ void userspace(struct uml_pt_regs *regs)
 		 * fail.  In this case, there is nothing to do but
 		 * just kill the process.
 		 */
-		if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp))
+		if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) {
+			printk(UM_KERN_ERR "userspace - ptrace set regs "
+			       "failed, errno = %d\n", errno);
 			fatal_sigsegv();
+		}
 
-		if (put_fp_registers(pid, regs->fp))
+		if (put_fp_registers(pid, regs->fp)) {
+			printk(UM_KERN_ERR "userspace - ptrace set fp regs "
+			       "failed, errno = %d\n", errno);
 			fatal_sigsegv();
+		}
 
 		/* Now we set local_using_sysemu to be used for one loop */
 		local_using_sysemu = get_using_sysemu();