920c52a5c
Denis Vlasenko
2007-09-28
Subject
hdparm: more robust (re overflows) code. +38 bytes.
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
miscutils/hdparm.c+23 -25
| @@ -1353,35 +1353,34 @@ static void read_big_block(/*int fd,*/ char *buf) | |
| buf[i] &= 1; | |
| } | |
| - | static unsigned long long dev_size_mb(/*int fd*/ void) |
| + | static unsigned dev_size_mb(/*int fd*/ void) |
| { | |
| union { | |
| unsigned long long blksize64; | |
| unsigned blksize32; | |
| } u; | |
| - | if (0 == ioctl(fd, BLKGETSIZE64, &u.blksize64)) { // returns bytes |
| - | return u.blksize64 / (1024 * 1024); |
| + | if (0 == ioctl(fd, BLKGETSIZE64, &u.blksize64)) { // bytes |
| + | u.blksize64 /= (1024 * 1024); |
| + | } else { |
| + | xioctl(fd, BLKGETSIZE, &u.blksize32); // sectors |
| + | u.blksize64 = u.blksize32 / (2 * 1024); |
| } | |
| - | xioctl(fd, BLKGETSIZE, &u.blksize32); // returns sectors |
| - | return u.blksize32 / (2 * 1024); |
| + | if (u.blksize64 > UINT_MAX) |
| + | return UINT_MAX; |
| + | return u.blksize64; |
| } | |
| - | static void print_timing(unsigned long m, unsigned elapsed_us) |
| + | static void print_timing(unsigned m, unsigned elapsed_us) |
| { | |
| unsigned sec = elapsed_us / 1000000; | |
| unsigned hs = (elapsed_us % 1000000) / 10000; | |
| - | printf("%5lu MB in %u.%02u seconds = %lu kB/s\n", |
| + | printf("%5u MB in %u.%02u seconds = %u kB/s\n", |
| m, sec, hs, | |
| - | /* Trying to not overflow 32-bit arith in m * CONST |
| - | * by keeping CONST not so big. But elapsed_us / CONST2 |
| - | * also should not introduce big errors. Currently, |
| - | * 16000us is ~1.6% of 1 second. |
| - | * "+ 1" prevents div-by-0. */ |
| - | (m * (1024 * 1000000 / (16*1024))) / (elapsed_us / (16*1024) + 1) |
| - | // ~= (m * 1024 * 1000000) / elapsed_us |
| - | // = (m * 1024) / (elapsed_us / 1000000) |
| + | /* + 1 prevents div-by-0 */ |
| + | (unsigned) ((unsigned long long)m * (1024 * 1000000) / (elapsed_us + 1)) |
| + | // ~= (m * 1024) / (elapsed_us / 1000000) |
| // = kb / elapsed_sec | |
| ); | |
| } | |
| @@ -1392,19 +1391,14 @@ static void do_time(int cache /*,int fd*/) | |
| */ | |
| { | |
| unsigned max_iterations, iterations; | |
| - | unsigned start; /* don't need to be long long */ |
| + | unsigned start; /* doesn't need to be long long */ |
| unsigned elapsed, elapsed2; | |
| - | unsigned long total_MB; |
| + | unsigned total_MB; |
| char *buf = xmalloc(TIMING_BUF_BYTES); | |
| if (mlock(buf, TIMING_BUF_BYTES)) | |
| bb_perror_msg_and_die("mlock"); | |
| - | /* Don't want to read past the end! */ |
| - | max_iterations = UINT_MAX; |
| - | if (!cache) |
| - | max_iterations = dev_size_mb() / TIMING_BUF_MB; |
| - | |
| /* Clear out the device request queues & give them time to complete. | |
| * NB: *small* delay. User is expected to have a clue and to not run | |
| * heavy io in parallel with measurements. */ | |
| @@ -1422,10 +1416,14 @@ static void do_time(int cache /*,int fd*/) | |
| /* Now do the timing */ | |
| iterations = 0; | |
| /* Max time to run (small for cache, avoids getting | |
| - | * huge total_MB which can overlow on print_timing) */ |
| + | * huge total_MB which can overlow unsigned type) */ |
| elapsed2 = 510000; /* cache */ | |
| - | if (!cache) |
| + | max_iterations = UINT_MAX; |
| + | if (!cache) { |
| elapsed2 = 3000000; /* not cache */ | |
| + | /* Don't want to read past the end! */ |
| + | max_iterations = dev_size_mb() / TIMING_BUF_MB; |
| + | } |
| start = monotonic_us(); | |
| do { | |
| if (cache) | |
| @@ -1434,7 +1432,7 @@ static void do_time(int cache /*,int fd*/) | |
| elapsed = (unsigned)monotonic_us() - start; | |
| ++iterations; | |
| } while (elapsed < elapsed2 && iterations < max_iterations); | |
| - | total_MB = (unsigned long)iterations * TIMING_BUF_MB; |
| + | total_MB = iterations * TIMING_BUF_MB; |
| //printf(" elapsed:%u iterations:%u ", elapsed, iterations); | |
| if (cache) { | |
| /* Cache: remove lseek() and monotonic_us() overheads | |