Updating cpuid_fault table is actually critical in terms of container migration (migrating with criu involves two stages: cpu matching and migration itself). If someone third side involves into cpuid_fault modification the migration may fail and we get not even a sign of what happened.
Thus to track cpuid_fault modifications simplier lets logs this action. | [ 186.708138] cpuid_override: 0x00000001: 0x000506e3 0x07100800 0x009ae3fd 0xbfebfbff | [ 186.715823] cpuid_override: 0x00000007 0x00000000: 0x00000000 0x00000000 0x00000000 0x00000000 | [ 186.724427] cpuid_override: 0x0000000d 0x00000001: 0x00000000 0x000003c0 0x00000100 0x00000000 | [ 186.733093] cpuid_override: 0x80000001: 0x00000000 0x00000000 0x00000001 0x2c100800 | [ 186.740746] cpuid_override: 0x80000007: 0x00000000 0x00000000 0x00000000 0x00000100 | [ 186.748469] cpuid_override: 0x80000008: 0x00003027 0x00000000 0x00000000 0x00000000 In a sake of https://jira.sw.ru/browse/PSBM-84029 Signed-off-by: Cyrill Gorcunov <gorcu...@openvz.org> --- arch/x86/kernel/cpuid_fault.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) Index: linux-pcs7.git/arch/x86/kernel/cpuid_fault.c =================================================================== --- linux-pcs7.git.orig/arch/x86/kernel/cpuid_fault.c +++ linux-pcs7.git/arch/x86/kernel/cpuid_fault.c @@ -13,6 +13,7 @@ #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/notifier.h> +#include <linux/ratelimit.h> #include <linux/reboot.h> #include <linux/ve.h> #include <asm/uaccess.h> @@ -61,6 +62,35 @@ void set_cpuid_faulting(bool enable) } EXPORT_SYMBOL(set_cpuid_faulting); +static void cpuid_override_info(struct cpuid_override_table *t) +{ + char buf[128]; + size_t pos; + + if (!t) { + pr_info_ratelimited("cpuid_override: flushed\n"); + return; + } + + rcu_read_lock(); + for (pos = 0; pos < t->size; pos++) { + struct cpuid_override_entry *e = &t->entries[pos]; + if (e->has_count) { + snprintf(buf, sizeof(buf), + "cpuid_override: 0x%08x 0x%08x: " + "0x%08x 0x%08x 0x%08x 0x%08x", + e->op, e->count, e->eax, e->ebx, e->ecx, e->edx); + } else { + snprintf(buf, sizeof(buf), + "cpuid_override: 0x%08x: " + "0x%08x 0x%08x 0x%08x 0x%08x", + e->op, e->eax, e->ebx, e->ecx, e->edx); + } + pr_info_ratelimited("%s\n", buf); + } + rcu_read_unlock(); +} + static void cpuid_override_update(struct cpuid_override_table *new_table) { struct cpuid_override_table *old_table; @@ -70,6 +100,8 @@ static void cpuid_override_update(struct rcu_assign_pointer(cpuid_override, new_table); spin_unlock(&cpuid_override_lock); + cpuid_override_info(new_table); + if (old_table) kfree_rcu(old_table, rcu_head); } _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
