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authorPetr Mladek <pmladek@suse.com>2016-09-21 13:47:22 +0200
committerJessica Yu <jeyu@redhat.com>2016-11-26 11:18:01 -0800
commit7fd8329ba502ef76dd91db561c7aed696b2c7720 (patch)
tree1cd64753819f07f811f0c0daabfdf72c952a089f /kernel
parentc7d47f26df949f0031fe2905068ee85db1b63ed9 (diff)
downloadop-kernel-dev-7fd8329ba502ef76dd91db561c7aed696b2c7720.zip
op-kernel-dev-7fd8329ba502ef76dd91db561c7aed696b2c7720.tar.gz
taint/module: Clean up global and module taint flags handling
The commit 66cc69e34e86a231 ("Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE") updated module_taint_flags() to potentially print one more character. But it did not increase the size of the corresponding buffers in m_show() and print_modules(). We have recently done the same mistake when adding a taint flag for livepatching, see https://lkml.kernel.org/r/cfba2c823bb984690b73572aaae1db596b54a082.1472137475.git.jpoimboe@redhat.com Also struct module uses an incompatible type for mod-taints flags. It survived from the commit 2bc2d61a9638dab670d ("[PATCH] list module taint flags in Oops/panic"). There was used "int" for the global taint flags at these times. But only the global tain flags was later changed to "unsigned long" by the commit 25ddbb18aae33ad2 ("Make the taint flags reliable"). This patch defines TAINT_FLAGS_COUNT that can be used to create arrays and buffers of the right size. Note that we could not use enum because the taint flag indexes are used also in assembly code. Then it reworks the table that describes the taint flags. The TAINT_* numbers can be used as the index. Instead, we add information if the taint flag is also shown per-module. Finally, it uses "unsigned long", bit operations, and the updated taint_flags table also for mod->taints. It is not optimal because only few taint flags can be printed by module_taint_flags(). But better be on the safe side. IMHO, it is not worth the optimization and this is a good compromise. Signed-off-by: Petr Mladek <pmladek@suse.com> Link: http://lkml.kernel.org/r/1474458442-21581-1-git-send-email-pmladek@suse.com [jeyu@redhat.com: fix broken lkml link in changelog] Signed-off-by: Jessica Yu <jeyu@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c33
-rw-r--r--kernel/panic.c53
2 files changed, 38 insertions, 48 deletions
diff --git a/kernel/module.c b/kernel/module.c
index f57dd63..a4acd8f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -330,7 +330,7 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
enum lockdep_ok lockdep_ok)
{
add_taint(flag, lockdep_ok);
- mod->taints |= (1U << flag);
+ set_bit(flag, &mod->taints);
}
/*
@@ -1138,24 +1138,13 @@ static inline int module_unload_init(struct module *mod)
static size_t module_flags_taint(struct module *mod, char *buf)
{
size_t l = 0;
+ int i;
+
+ for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
+ if (taint_flags[i].module && test_bit(i, &mod->taints))
+ buf[l++] = taint_flags[i].true;
+ }
- if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
- buf[l++] = 'P';
- if (mod->taints & (1 << TAINT_OOT_MODULE))
- buf[l++] = 'O';
- if (mod->taints & (1 << TAINT_FORCED_MODULE))
- buf[l++] = 'F';
- if (mod->taints & (1 << TAINT_CRAP))
- buf[l++] = 'C';
- if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
- buf[l++] = 'E';
- if (mod->taints & (1 << TAINT_LIVEPATCH))
- buf[l++] = 'K';
- /*
- * TAINT_FORCED_RMMOD: could be added.
- * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
- * apply to modules.
- */
return l;
}
@@ -4041,6 +4030,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
}
#endif /* CONFIG_KALLSYMS */
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+
+/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
@@ -4085,7 +4078,7 @@ static void m_stop(struct seq_file *m, void *p)
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
- char buf[8];
+ char buf[MODULE_FLAGS_BUF_SIZE];
/* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED)
@@ -4256,7 +4249,7 @@ EXPORT_SYMBOL_GPL(__module_text_address);
void print_modules(void)
{
struct module *mod;
- char buf[8];
+ char buf[MODULE_FLAGS_BUF_SIZE];
printk(KERN_DEFAULT "Modules linked in:");
/* Most callers should already have preempt disabled, but make sure */
diff --git a/kernel/panic.c b/kernel/panic.c
index e6480e2..c51edaa 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -298,30 +298,27 @@ void panic(const char *fmt, ...)
EXPORT_SYMBOL(panic);
-
-struct tnt {
- u8 bit;
- char true;
- char false;
-};
-
-static const struct tnt tnts[] = {
- { TAINT_PROPRIETARY_MODULE, 'P', 'G' },
- { TAINT_FORCED_MODULE, 'F', ' ' },
- { TAINT_CPU_OUT_OF_SPEC, 'S', ' ' },
- { TAINT_FORCED_RMMOD, 'R', ' ' },
- { TAINT_MACHINE_CHECK, 'M', ' ' },
- { TAINT_BAD_PAGE, 'B', ' ' },
- { TAINT_USER, 'U', ' ' },
- { TAINT_DIE, 'D', ' ' },
- { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
- { TAINT_WARN, 'W', ' ' },
- { TAINT_CRAP, 'C', ' ' },
- { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' },
- { TAINT_OOT_MODULE, 'O', ' ' },
- { TAINT_UNSIGNED_MODULE, 'E', ' ' },
- { TAINT_SOFTLOCKUP, 'L', ' ' },
- { TAINT_LIVEPATCH, 'K', ' ' },
+/*
+ * TAINT_FORCED_RMMOD could be a per-module flag but the module
+ * is being removed anyway.
+ */
+const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
+ { 'P', 'G', true }, /* TAINT_PROPRIETARY_MODULE */
+ { 'F', ' ', true }, /* TAINT_FORCED_MODULE */
+ { 'S', ' ', false }, /* TAINT_CPU_OUT_OF_SPEC */
+ { 'R', ' ', false }, /* TAINT_FORCED_RMMOD */
+ { 'M', ' ', false }, /* TAINT_MACHINE_CHECK */
+ { 'B', ' ', false }, /* TAINT_BAD_PAGE */
+ { 'U', ' ', false }, /* TAINT_USER */
+ { 'D', ' ', false }, /* TAINT_DIE */
+ { 'A', ' ', false }, /* TAINT_OVERRIDDEN_ACPI_TABLE */
+ { 'W', ' ', false }, /* TAINT_WARN */
+ { 'C', ' ', true }, /* TAINT_CRAP */
+ { 'I', ' ', false }, /* TAINT_FIRMWARE_WORKAROUND */
+ { 'O', ' ', true }, /* TAINT_OOT_MODULE */
+ { 'E', ' ', true }, /* TAINT_UNSIGNED_MODULE */
+ { 'L', ' ', false }, /* TAINT_SOFTLOCKUP */
+ { 'K', ' ', true }, /* TAINT_LIVEPATCH */
};
/**
@@ -348,16 +345,16 @@ static const struct tnt tnts[] = {
*/
const char *print_tainted(void)
{
- static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")];
+ static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
if (tainted_mask) {
char *s;
int i;
s = buf + sprintf(buf, "Tainted: ");
- for (i = 0; i < ARRAY_SIZE(tnts); i++) {
- const struct tnt *t = &tnts[i];
- *s++ = test_bit(t->bit, &tainted_mask) ?
+ for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
+ const struct taint_flag *t = &taint_flags[i];
+ *s++ = test_bit(i, &tainted_mask) ?
t->true : t->false;
}
*s = 0;
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