Commit 7fd8329b authored by Petr Mladek's avatar Petr Mladek Committed by Jessica Yu

taint/module: Clean up global and module taint flags handling

The commit 66cc69e3 ("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 2bc2d61a ("[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 25ddbb18 ("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: default avatarPetr 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: default avatarJessica Yu <jeyu@redhat.com>
parent c7d47f26
...@@ -506,6 +506,15 @@ extern enum system_states { ...@@ -506,6 +506,15 @@ extern enum system_states {
#define TAINT_UNSIGNED_MODULE 13 #define TAINT_UNSIGNED_MODULE 13
#define TAINT_SOFTLOCKUP 14 #define TAINT_SOFTLOCKUP 14
#define TAINT_LIVEPATCH 15 #define TAINT_LIVEPATCH 15
#define TAINT_FLAGS_COUNT 16
struct taint_flag {
char true; /* character printed when tainted */
char false; /* character printed when not tainted */
bool module; /* also show as a per-module taint flag */
};
extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
extern const char hex_asc[]; extern const char hex_asc[];
#define hex_asc_lo(x) hex_asc[((x) & 0x0f)] #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
......
...@@ -399,7 +399,7 @@ struct module { ...@@ -399,7 +399,7 @@ struct module {
/* Arch-specific module values */ /* Arch-specific module values */
struct mod_arch_specific arch; struct mod_arch_specific arch;
unsigned int taints; /* same bits as kernel:tainted */ unsigned long taints; /* same bits as kernel:taint_flags */
#ifdef CONFIG_GENERIC_BUG #ifdef CONFIG_GENERIC_BUG
/* Support for BUG */ /* Support for BUG */
......
...@@ -330,7 +330,7 @@ static inline void add_taint_module(struct module *mod, unsigned flag, ...@@ -330,7 +330,7 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
enum lockdep_ok lockdep_ok) enum lockdep_ok lockdep_ok)
{ {
add_taint(flag, 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) ...@@ -1138,24 +1138,13 @@ static inline int module_unload_init(struct module *mod)
static size_t module_flags_taint(struct module *mod, char *buf) static size_t module_flags_taint(struct module *mod, char *buf)
{ {
size_t l = 0; 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; return l;
} }
...@@ -4041,6 +4030,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, ...@@ -4041,6 +4030,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
} }
#endif /* CONFIG_KALLSYMS */ #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) static char *module_flags(struct module *mod, char *buf)
{ {
int bx = 0; int bx = 0;
...@@ -4085,7 +4078,7 @@ static void m_stop(struct seq_file *m, void *p) ...@@ -4085,7 +4078,7 @@ static void m_stop(struct seq_file *m, void *p)
static int m_show(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); struct module *mod = list_entry(p, struct module, list);
char buf[8]; char buf[MODULE_FLAGS_BUF_SIZE];
/* We always ignore unformed modules. */ /* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED) if (mod->state == MODULE_STATE_UNFORMED)
...@@ -4256,7 +4249,7 @@ EXPORT_SYMBOL_GPL(__module_text_address); ...@@ -4256,7 +4249,7 @@ EXPORT_SYMBOL_GPL(__module_text_address);
void print_modules(void) void print_modules(void)
{ {
struct module *mod; struct module *mod;
char buf[8]; char buf[MODULE_FLAGS_BUF_SIZE];
printk(KERN_DEFAULT "Modules linked in:"); printk(KERN_DEFAULT "Modules linked in:");
/* Most callers should already have preempt disabled, but make sure */ /* Most callers should already have preempt disabled, but make sure */
......
...@@ -298,30 +298,27 @@ void panic(const char *fmt, ...) ...@@ -298,30 +298,27 @@ void panic(const char *fmt, ...)
EXPORT_SYMBOL(panic); EXPORT_SYMBOL(panic);
/*
struct tnt { * TAINT_FORCED_RMMOD could be a per-module flag but the module
u8 bit; * is being removed anyway.
char true; */
char false; const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
}; { 'P', 'G', true }, /* TAINT_PROPRIETARY_MODULE */
{ 'F', ' ', true }, /* TAINT_FORCED_MODULE */
static const struct tnt tnts[] = { { 'S', ' ', false }, /* TAINT_CPU_OUT_OF_SPEC */
{ TAINT_PROPRIETARY_MODULE, 'P', 'G' }, { 'R', ' ', false }, /* TAINT_FORCED_RMMOD */
{ TAINT_FORCED_MODULE, 'F', ' ' }, { 'M', ' ', false }, /* TAINT_MACHINE_CHECK */
{ TAINT_CPU_OUT_OF_SPEC, 'S', ' ' }, { 'B', ' ', false }, /* TAINT_BAD_PAGE */
{ TAINT_FORCED_RMMOD, 'R', ' ' }, { 'U', ' ', false }, /* TAINT_USER */
{ TAINT_MACHINE_CHECK, 'M', ' ' }, { 'D', ' ', false }, /* TAINT_DIE */
{ TAINT_BAD_PAGE, 'B', ' ' }, { 'A', ' ', false }, /* TAINT_OVERRIDDEN_ACPI_TABLE */
{ TAINT_USER, 'U', ' ' }, { 'W', ' ', false }, /* TAINT_WARN */
{ TAINT_DIE, 'D', ' ' }, { 'C', ' ', true }, /* TAINT_CRAP */
{ TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' }, { 'I', ' ', false }, /* TAINT_FIRMWARE_WORKAROUND */
{ TAINT_WARN, 'W', ' ' }, { 'O', ' ', true }, /* TAINT_OOT_MODULE */
{ TAINT_CRAP, 'C', ' ' }, { 'E', ' ', true }, /* TAINT_UNSIGNED_MODULE */
{ TAINT_FIRMWARE_WORKAROUND, 'I', ' ' }, { 'L', ' ', false }, /* TAINT_SOFTLOCKUP */
{ TAINT_OOT_MODULE, 'O', ' ' }, { 'K', ' ', true }, /* TAINT_LIVEPATCH */
{ TAINT_UNSIGNED_MODULE, 'E', ' ' },
{ TAINT_SOFTLOCKUP, 'L', ' ' },
{ TAINT_LIVEPATCH, 'K', ' ' },
}; };
/** /**
...@@ -348,16 +345,16 @@ static const struct tnt tnts[] = { ...@@ -348,16 +345,16 @@ static const struct tnt tnts[] = {
*/ */
const char *print_tainted(void) const char *print_tainted(void)
{ {
static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")]; static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
if (tainted_mask) { if (tainted_mask) {
char *s; char *s;
int i; int i;
s = buf + sprintf(buf, "Tainted: "); s = buf + sprintf(buf, "Tainted: ");
for (i = 0; i < ARRAY_SIZE(tnts); i++) { for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
const struct tnt *t = &tnts[i]; const struct taint_flag *t = &taint_flags[i];
*s++ = test_bit(t->bit, &tainted_mask) ? *s++ = test_bit(i, &tainted_mask) ?
t->true : t->false; t->true : t->false;
} }
*s = 0; *s = 0;
......
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