From 4611a6fa4b37cf6b8b6066ed0d605c994c62a1a0 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 27 May 2009 21:56:57 +0200 Subject: [PATCH] x86, mce: export MCE severities coverage via debugfs The MCE severity judgement code is data-driven, so code coverage tools such as gcov can not be used for measuring coverage. Instead a dedicated coverage mechanism is implemented. The kernel keeps track of rules executed and reports them in debugfs. This is useful for increasing coverage of the mce-test testsuite. Right now it's unconditionally enabled because it's very little code. Signed-off-by: Huang Ying Signed-off-by: Andi Kleen Signed-off-by: Hidetoshi Seto Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mcheck/mce-severity.c | 83 +++++++++++++++++++++++ 1 file changed, 83 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c index 4f4d2caf404..ff0807f9705 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -10,6 +10,9 @@ * Author: Andi Kleen */ #include +#include +#include +#include #include #include "mce-internal.h" @@ -37,6 +40,7 @@ static struct severity { unsigned char mcgres; unsigned char ser; unsigned char context; + unsigned char covered; char *msg; } severities[] = { #define KERNEL .context = IN_KERNEL @@ -126,6 +130,7 @@ int mce_severity(struct mce *a, int tolerant, char **msg) continue; if (msg) *msg = s->msg; + s->covered = 1; if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) { if (panic_on_oops || tolerant < 1) return MCE_PANIC_SEVERITY; @@ -133,3 +138,81 @@ int mce_severity(struct mce *a, int tolerant, char **msg) return s->sev; } } + +static void *s_start(struct seq_file *f, loff_t *pos) +{ + if (*pos >= ARRAY_SIZE(severities)) + return NULL; + return &severities[*pos]; +} + +static void *s_next(struct seq_file *f, void *data, loff_t *pos) +{ + if (++(*pos) >= ARRAY_SIZE(severities)) + return NULL; + return &severities[*pos]; +} + +static void s_stop(struct seq_file *f, void *data) +{ +} + +static int s_show(struct seq_file *f, void *data) +{ + struct severity *ser = data; + seq_printf(f, "%d\t%s\n", ser->covered, ser->msg); + return 0; +} + +static const struct seq_operations severities_seq_ops = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int severities_coverage_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &severities_seq_ops); +} + +static ssize_t severities_coverage_write(struct file *file, + const char __user *ubuf, + size_t count, loff_t *ppos) +{ + int i; + for (i = 0; i < ARRAY_SIZE(severities); i++) + severities[i].covered = 0; + return count; +} + +static const struct file_operations severities_coverage_fops = { + .open = severities_coverage_open, + .release = seq_release, + .read = seq_read, + .write = severities_coverage_write, +}; + +static int __init severities_debugfs_init(void) +{ + struct dentry *dmce = NULL, *fseverities_coverage = NULL; + + dmce = debugfs_create_dir("mce", NULL); + if (dmce == NULL) + goto err_out; + fseverities_coverage = debugfs_create_file("severities-coverage", + 0444, dmce, NULL, + &severities_coverage_fops); + if (fseverities_coverage == NULL) + goto err_out; + + return 0; + +err_out: + if (fseverities_coverage) + debugfs_remove(fseverities_coverage); + if (dmce) + debugfs_remove(dmce); + return -ENOMEM; +} +late_initcall(severities_debugfs_init); -- 2.39.3