From 00ce1db1a634746040ace24c09a4e3a7949a3145 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 4 Jul 2012 16:19:30 -0400 Subject: [PATCH] random: add tracepoints for easier debugging and verification Signed-off-by: "Theodore Ts'o" --- drivers/char/random.c | 26 ++++++- include/trace/events/random.h | 134 ++++++++++++++++++++++++++++++++++ 2 files changed, 156 insertions(+), 4 deletions(-) create mode 100644 include/trace/events/random.h diff --git a/drivers/char/random.c b/drivers/char/random.c index eacd6147911..e3180852ec8 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -266,6 +266,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + /* * Configuration information */ @@ -478,8 +481,8 @@ static __u32 const twist_table[8] = { * it's cheap to do so and helps slightly in the expected case where * the entropy is concentrated in the low-order bits. */ -static void __mix_pool_bytes(struct entropy_store *r, const void *in, - int nbytes, __u8 out[64]) +static void _mix_pool_bytes(struct entropy_store *r, const void *in, + int nbytes, __u8 out[64]) { unsigned long i, j, tap1, tap2, tap3, tap4, tap5; int input_rotate; @@ -531,13 +534,21 @@ static void __mix_pool_bytes(struct entropy_store *r, const void *in, ((__u32 *)out)[j] = r->pool[(i - j) & wordmask]; } -static void mix_pool_bytes(struct entropy_store *r, const void *in, +static void __mix_pool_bytes(struct entropy_store *r, const void *in, int nbytes, __u8 out[64]) +{ + trace_mix_pool_bytes_nolock(r->name, nbytes, _RET_IP_); + _mix_pool_bytes(r, in, nbytes, out); +} + +static void mix_pool_bytes(struct entropy_store *r, const void *in, + int nbytes, __u8 out[64]) { unsigned long flags; + trace_mix_pool_bytes(r->name, nbytes, _RET_IP_); spin_lock_irqsave(&r->lock, flags); - __mix_pool_bytes(r, in, nbytes, out); + _mix_pool_bytes(r, in, nbytes, out); spin_unlock_irqrestore(&r->lock, flags); } @@ -585,6 +596,7 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits) retry: entropy_count = orig = ACCESS_ONCE(r->entropy_count); entropy_count += nbits; + if (entropy_count < 0) { DEBUG_ENT("negative entropy/overflow\n"); entropy_count = 0; @@ -599,6 +611,9 @@ retry: r->initialized = 1; } + trace_credit_entropy_bits(r->name, nbits, entropy_count, + r->entropy_total, _RET_IP_); + /* should we wake readers? */ if (r == &input_pool && entropy_count >= random_read_wakeup_thresh) { wake_up_interruptible(&random_read_wait); @@ -971,6 +986,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, ssize_t ret = 0, i; __u8 tmp[EXTRACT_SIZE]; + trace_extract_entropy(r->name, nbytes, r->entropy_count, _RET_IP_); xfer_secondary_pool(r, nbytes); nbytes = account(r, nbytes, min, reserved); @@ -1005,6 +1021,7 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, ssize_t ret = 0, i; __u8 tmp[EXTRACT_SIZE]; + trace_extract_entropy_user(r->name, nbytes, r->entropy_count, _RET_IP_); xfer_secondary_pool(r, nbytes); nbytes = account(r, nbytes, 0, 0); @@ -1062,6 +1079,7 @@ void get_random_bytes_arch(void *buf, int nbytes) { char *p = buf; + trace_get_random_bytes(nbytes, _RET_IP_); while (nbytes) { unsigned long v; int chunk = min(nbytes, (int)sizeof(unsigned long)); diff --git a/include/trace/events/random.h b/include/trace/events/random.h new file mode 100644 index 00000000000..422df19de73 --- /dev/null +++ b/include/trace/events/random.h @@ -0,0 +1,134 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM random + +#if !defined(_TRACE_RANDOM_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_RANDOM_H + +#include +#include + +DECLARE_EVENT_CLASS(random__mix_pool_bytes, + TP_PROTO(const char *pool_name, int bytes, unsigned long IP), + + TP_ARGS(pool_name, bytes, IP), + + TP_STRUCT__entry( + __field( const char *, pool_name ) + __field( int, bytes ) + __field(unsigned long, IP ) + ), + + TP_fast_assign( + __entry->pool_name = pool_name; + __entry->bytes = bytes; + __entry->IP = IP; + ), + + TP_printk("%s pool: bytes %d caller %pF", + __entry->pool_name, __entry->bytes, (void *)__entry->IP) +); + +DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes, + TP_PROTO(const char *pool_name, int bytes, unsigned long IP), + + TP_ARGS(pool_name, bytes, IP) +); + +DEFINE_EVENT(random__mix_pool_bytes, mix_pool_bytes_nolock, + TP_PROTO(const char *pool_name, int bytes, unsigned long IP), + + TP_ARGS(pool_name, bytes, IP) +); + +TRACE_EVENT(credit_entropy_bits, + TP_PROTO(const char *pool_name, int bits, int entropy_count, + int entropy_total, unsigned long IP), + + TP_ARGS(pool_name, bits, entropy_count, entropy_total, IP), + + TP_STRUCT__entry( + __field( const char *, pool_name ) + __field( int, bits ) + __field( int, entropy_count ) + __field( int, entropy_total ) + __field(unsigned long, IP ) + ), + + TP_fast_assign( + __entry->pool_name = pool_name; + __entry->bits = bits; + __entry->entropy_count = entropy_count; + __entry->entropy_total = entropy_total; + __entry->IP = IP; + ), + + TP_printk("%s pool: bits %d entropy_count %d entropy_total %d " + "caller %pF", __entry->pool_name, __entry->bits, + __entry->entropy_count, __entry->entropy_total, + (void *)__entry->IP) +); + +TRACE_EVENT(get_random_bytes, + TP_PROTO(int nbytes, unsigned long IP), + + TP_ARGS(nbytes, IP), + + TP_STRUCT__entry( + __field( int, nbytes ) + __field(unsigned long, IP ) + ), + + TP_fast_assign( + __entry->nbytes = nbytes; + __entry->IP = IP; + ), + + TP_printk("nbytes %d caller %pF", __entry->nbytes, (void *)__entry->IP) +); + +DECLARE_EVENT_CLASS(random__extract_entropy, + TP_PROTO(const char *pool_name, int nbytes, int entropy_count, + unsigned long IP), + + TP_ARGS(pool_name, nbytes, entropy_count, IP), + + TP_STRUCT__entry( + __field( const char *, pool_name ) + __field( int, nbytes ) + __field( int, entropy_count ) + __field(unsigned long, IP ) + ), + + TP_fast_assign( + __entry->pool_name = pool_name; + __entry->nbytes = nbytes; + __entry->entropy_count = entropy_count; + __entry->IP = IP; + ), + + TP_printk("%s pool: nbytes %d entropy_count %d caller %pF", + __entry->pool_name, __entry->nbytes, __entry->entropy_count, + (void *)__entry->IP) +); + + +DEFINE_EVENT(random__extract_entropy, extract_entropy, + TP_PROTO(const char *pool_name, int nbytes, int entropy_count, + unsigned long IP), + + TP_ARGS(pool_name, nbytes, entropy_count, IP) +); + +DEFINE_EVENT(random__extract_entropy, extract_entropy_user, + TP_PROTO(const char *pool_name, int nbytes, int entropy_count, + unsigned long IP), + + TP_ARGS(pool_name, nbytes, entropy_count, IP) +); + + + +#endif /* _TRACE_RANDOM_H */ + +/* This part must be outside protection */ +#include -- 2.20.1