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author | Theodore Ts'o <tytso@mit.edu> | 2012-07-05 00:19:30 +0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2012-07-15 04:17:48 +0400 |
commit | 00ce1db1a634746040ace24c09a4e3a7949a3145 (patch) | |
tree | a9c97eab912d149ebaaab3dc3393d75416b5c6b4 /drivers/char/random.c | |
parent | c2557a303ab6712bb6e09447df828c557c710ac9 (diff) | |
download | linux-00ce1db1a634746040ace24c09a4e3a7949a3145.tar.xz |
random: add tracepoints for easier debugging and verification
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r-- | drivers/char/random.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index eacd61479112..e3180852ec85 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -266,6 +266,9 @@ #include <asm/irq_regs.h> #include <asm/io.h> +#define CREATE_TRACE_POINTS +#include <trace/events/random.h> + /* * 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)); |