integration: add a function pointer / klp-relocation test

Add an integration test to verify klp-relocation replacement of certain
function pointers.  In this test, the livepatch's function pointer to
uptime_proc_show should resolve to the original found in the kernel and
not the instance from the livepatch itself.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>

Author: joe-lawrence

test/integration/rhel-7.9/func-ptr-klp_reloc.patch

@@ -0,0 +1,17 @@
+--- src.old/fs/proc/uptime.c	2024-06-13 03:19:08.000000000 -0400
++++ src/fs/proc/uptime.c	2025-03-25 09:08:38.206910364 -0400
+@@ -24,11 +24,12 @@ static int uptime_proc_show(struct seq_f
+ 	nsec = cputime64_to_jiffies64(idletime) * TICK_NSEC;
+ 	idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
+ 	idle.tv_nsec = rem;
+-	seq_printf(m, "%lu.%02lu %lu.%02lu\n",
++	seq_printf(m, "%lu.%02lu %lu.%02lu uptime_proc_show=%p\n",
+ 			(unsigned long) uptime.tv_sec,
+ 			(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+ 			(unsigned long) idle.tv_sec,
+-			(idle.tv_nsec / (NSEC_PER_SEC / 100)));
++			(idle.tv_nsec / (NSEC_PER_SEC / 100)),
++			uptime_proc_show);
+ 	return 0;
+ }
+ 

test/integration/rhel-7.9/func-ptr-klp_reloc.test

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+kpatch_value=$(cat /proc/uptime | grep -o 'uptime_proc_show=.*' | awk -F= '{print $2}')
+kernel_value=$(awk '$NF=="uptime_proc_show" { print $1 }' /proc/kallsyms)
+
+if [[ "$kpatch_value" != "$kernel_value" ]]; then
+        echo "kpatch_value($kpatch_value) != kernel_value($kernel_value)"
+        exit 1
+fi

test/integration/rhel-8.10/func-ptr-klp_reloc.patch

@@ -0,0 +1,17 @@
+--- src.old/fs/proc/uptime.c	2025-03-20 06:57:19.000000000 -0400
++++ src/fs/proc/uptime.c	2025-03-25 09:35:50.847697946 -0400
+@@ -25,11 +25,12 @@ static int uptime_proc_show(struct seq_f
+ 
+ 	idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
+ 	idle.tv_nsec = rem;
+-	seq_printf(m, "%lu.%02lu %lu.%02lu\n",
++	seq_printf(m, "%lu.%02lu %lu.%02lu uptime_proc_show=%pK\n",
+ 			(unsigned long) uptime.tv_sec,
+ 			(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+ 			(unsigned long) idle.tv_sec,
+-			(idle.tv_nsec / (NSEC_PER_SEC / 100)));
++			(idle.tv_nsec / (NSEC_PER_SEC / 100)),
++			uptime_proc_show);
+ 	return 0;
+ }
+ 

test/integration/rhel-8.10/func-ptr-klp_reloc.test

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+kpatch_value=$(cat /proc/uptime | grep -o 'uptime_proc_show=.*' | awk -F= '{print $2}')
+kernel_value=$(awk '$NF=="uptime_proc_show" { print $1 }' /proc/kallsyms)
+
+if [[ "$kpatch_value" != "$kernel_value" ]]; then
+        echo "kpatch_value($kpatch_value) != kernel_value($kernel_value)"
+        exit 1
+fi

test/integration/rhel-9.5/func-ptr-klp_reloc.patch

@@ -0,0 +1,17 @@
+--- src.old/fs/proc/uptime.c	2025-03-25 09:35:31.468574086 -0400
++++ src/fs/proc/uptime.c	2025-03-25 09:35:46.848570153 -0400
+@@ -29,11 +29,12 @@ static int uptime_proc_show(struct seq_f
+ 
+ 	idle.tv_sec = div_u64_rem(idle_nsec, NSEC_PER_SEC, &rem);
+ 	idle.tv_nsec = rem;
+-	seq_printf(m, "%lu.%02lu %lu.%02lu\n",
++	seq_printf(m, "%lu.%02lu %lu.%02lu uptime_proc_show=%pK\n",
+ 			(unsigned long) uptime.tv_sec,
+ 			(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+ 			(unsigned long) idle.tv_sec,
+-			(idle.tv_nsec / (NSEC_PER_SEC / 100)));
++			(idle.tv_nsec / (NSEC_PER_SEC / 100)),
++			uptime_proc_show);
+ 	return 0;
+ }
+ 

test/integration/rhel-9.5/func-ptr-klp_reloc.test

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+kpatch_value=$(cat /proc/uptime | grep -o 'uptime_proc_show=.*' | awk -F= '{print $2}')
+kernel_value=$(awk '$NF=="uptime_proc_show" { print $1 }' /proc/kallsyms)
+
+if [[ "$kpatch_value" != "$kernel_value" ]]; then
+        echo "kpatch_value($kpatch_value) != kernel_value($kernel_value)"
+        exit 1
+fi