test/integration: Add tests for patching a syscall

Add ".kpatch" to the end of "uname -s".

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

test/integration/linux-5.10.11/syscall-LOADED.test

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+uname -s | grep -q kpatch

test/integration/linux-5.10.11/syscall.patch

@@ -0,0 +1,21 @@
+diff --git a/kernel/sys.c b/kernel/sys.c
+index 2e2e3f378d97..05271fe26c89 100644
+--- a/kernel/sys.c
++++ b/kernel/sys.c
+@@ -1250,13 +1250,15 @@ static int override_release(char __user *release, size_t len)
+ 	return ret;
+ }
+ 
+-SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
++#include "kpatch-syscall.h"
++KPATCH_SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
+ {
+ 	struct new_utsname tmp;
+ 
+ 	down_read(&uts_sem);
+ 	memcpy(&tmp, utsname(), sizeof(tmp));
+ 	up_read(&uts_sem);
++	strcat(tmp.sysname, ".kpatch");
+ 	if (copy_to_user(name, &tmp, sizeof(tmp)))
+ 		return -EFAULT;
+ 

test/integration/rhel-7.9/syscall-LOADED.test

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+uname -s | grep -q kpatch

test/integration/rhel-7.9/syscall.patch

@@ -0,0 +1,26 @@
+diff --git a/kernel/sys.c b/kernel/sys.c
+index 1fbf388279832..b5186aa83adfa 100644
+--- a/kernel/sys.c
++++ b/kernel/sys.c
+@@ -1392,14 +1392,18 @@ static int override_release(char __user *release, size_t len)
+ 	return ret;
+ }
+ 
+-SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
++#include "kpatch-syscall.h"
++KPATCH_SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
+ {
++	struct new_utsname tmp;
+ 	int errno = 0;
+ 
+ 	down_read(&uts_sem);
+-	if (copy_to_user(name, utsname(), sizeof *name))
+-		errno = -EFAULT;
++	memcpy(&tmp, utsname(), sizeof(tmp));
+ 	up_read(&uts_sem);
++	strcat(tmp.sysname, ".kpatch");
++	if (copy_to_user(name, &tmp, sizeof(tmp)))
++		errno = -EFAULT;
+ 
+ 	if (!errno && override_release(name->release, sizeof(name->release)))
+ 		errno = -EFAULT;

test/integration/rhel-8.4/syscall-LOADED.test

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+uname -s | grep -q kpatch

test/integration/rhel-8.4/syscall.patch

@@ -0,0 +1,26 @@
+diff --git a/kernel/sys.c b/kernel/sys.c
+index 871c0848f05c8..479bf8725d2e6 100644
+--- a/kernel/sys.c
++++ b/kernel/sys.c
+@@ -1241,14 +1241,18 @@ static int override_release(char __user *release, size_t len)
+ 	return ret;
+ }
+ 
+-SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
++#include "kpatch-syscall.h"
++KPATCH_SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
+ {
++	struct new_utsname tmp;
+ 	int errno = 0;
+ 
+ 	down_read(&uts_sem);
+-	if (copy_to_user(name, utsname(), sizeof *name))
+-		errno = -EFAULT;
++	memcpy(&tmp, utsname(), sizeof(tmp));
+ 	up_read(&uts_sem);
++	strcat(tmp.sysname, ".kpatch");
++	if (copy_to_user(name, &tmp, sizeof(tmp)))
++		errno = -EFAULT;
+ 
+ 	if (!errno && override_release(name->release, sizeof(name->release)))
+ 		errno = -EFAULT;