From 08078d00ab1749a6f84148a00d8d26572af4ec97 Mon Sep 17 00:00:00 2001 Message-Id: <08078d00ab1749a6f84148a00d8d26572af4ec97.1586900628.git.jpoimboe@redhat.com> From: Josh Poimboeuf Date: Tue, 14 Apr 2020 15:17:51 -0500 Subject: [PATCH] kpatch module integration test This tests several things related to the patching of modules: - 'kpatch_string' tests the referencing of a symbol which is outside the .o, but inside the patch module. - alternatives patching (.altinstructions) - paravirt patching (.parainstructions) - jump labels (5.8+ kernels only) -- including dynamic printk Signed-off-by: Josh Poimboeuf --- fs/nfsd/export.c | 30 ++++++++++++++++++++++++++++++ net/netlink/af_netlink.c | 5 +++++ 2 files changed, 35 insertions(+) diff -Nupr src.orig/fs/nfsd/export.c src/fs/nfsd/export.c --- src.orig/fs/nfsd/export.c 2022-10-24 15:41:08.846760255 -0400 +++ src/fs/nfsd/export.c 2022-10-24 15:41:52.672070238 -0400 @@ -1228,15 +1228,45 @@ static void exp_flags(struct seq_file *m } } +#include +extern char *kpatch_string(void); + static int e_show(struct seq_file *m, void *p) { struct cache_head *cp = p; struct svc_export *exp = container_of(cp, struct svc_export, h); struct cache_detail *cd = m->private; +#ifdef CONFIG_X86_64 + unsigned long long sched_clock; + + alternative("ud2", "call yield", X86_FEATURE_ALWAYS); + alternative("call yield", "ud2", X86_FEATURE_IA64); + + sched_clock = paravirt_sched_clock(); + if (!jiffies) + printk("kpatch: sched_clock: %llu\n", sched_clock); +#endif + + pr_debug("kpatch: pr_debug() test\n"); + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0) +{ + static DEFINE_STATIC_KEY_TRUE(kpatch_key); + + if (static_branch_unlikely(&mcsafe_key)) + printk("kpatch: mcsafe_key\n"); + + BUG_ON(!static_branch_likely(&kpatch_key)); + static_branch_disable(&kpatch_key); + BUG_ON(static_branch_likely(&kpatch_key)); + static_branch_enable(&kpatch_key); +} +#endif if (p == SEQ_START_TOKEN) { seq_puts(m, "# Version 1.1\n"); seq_puts(m, "# Path Client(Flags) # IPs\n"); + seq_puts(m, kpatch_string()); return 0; } diff -Nupr src.orig/net/netlink/af_netlink.c src/net/netlink/af_netlink.c --- src.orig/net/netlink/af_netlink.c 2022-10-24 15:41:09.080756571 -0400 +++ src/net/netlink/af_netlink.c 2022-10-24 15:41:52.672070238 -0400 @@ -2887,4 +2887,9 @@ panic: panic("netlink_init: Cannot allocate nl_table\n"); } +char *kpatch_string(void) +{ + return "# kpatch\n"; +} + core_initcall(netlink_proto_init);