Hi Petr and Lianbo, Sorry for the late reply. I will merge the patch into V1.6.4. Thanks Tachibana > -----Original Message----- > From: Petr Tesarik [mailto:ptesarik@xxxxxxx] > Sent: Tuesday, April 10, 2018 8:39 PM > To: lijiang <lijiang@xxxxxxxxxx> > Cc: Tachibana Masaki() <mas-tachibana@xxxxxxxxxxxxx>; Nakayama Takuya() <tak-nakayama@xxxxxxxxxxxxx>; > kexec-ml <kexec@xxxxxxxxxxxxxxxxxxx> > Subject: [PATCH v2] makedumpfile: Use integer arithmetics for the progress bar > > Essentially, the estimated remaining time is calculated as: > > elapsed * (100 - progress) / progress > > Since the calculation is done with floating point numbers, it had > masked a division by zero (if progress is 0), producing a NaN or > infinity. The following conversion to int produces INT_MIN with GCC > on major platforms, which originally overflowed the eta buffer. This > bug was fixed by commit e5f96e79d69a1d295f19130da00ec6514d28a8ae, > but conversion of NaN and infinity is undefined behaviour in ISO C, > plus the corresponding output is still wrong, e.g.: > > Copying data : [ 0.0 %] / eta: -9223372036854775808s > > Most importantly, using the FPU for a progress bar is overkill. > Since the progress percentage is reported with one decimal digit > following the decimal point, it can be stored as an integer tenths > of a percent. > > Second, the estimated time can be calculated in milliseconds. Up to > 49 days can be represented this way even on 32-bit platforms. Note > that delta.tv_usec can be ignored in the subtraction, because the > resulting eta is printed as seconds, so elapsed microseconds are > irrelevant. > > Last but not least, the original buffer overflow was probably caused > by the wrong assumption that integers < 100 can be interpreted with > less than 3 ASCII characters, but that's not true for signed > integers. To make eta_to_human_short() a bit safer, use an unsigned > integer type. > > Signed-off-by: Petr Tesarik <ptesarik@xxxxxxxx> > --- > print_info.c | 43 ++++++++++++++++++++----------------------- > 1 file changed, 20 insertions(+), 23 deletions(-) > > diff --git a/print_info.c b/print_info.c > index 09e215a..6bfcd11 100644 > --- a/print_info.c > +++ b/print_info.c > @@ -16,8 +16,6 @@ > #include "print_info.h" > #include <time.h> > #include <string.h> > -#include <stdint.h> > -#include <inttypes.h> > > #define PROGRESS_MAXLEN "50" > > @@ -354,21 +352,18 @@ static void calc_delta(struct timeval *tv_start, struct timeval *delta) > } > > /* produce less than 12 bytes on msg */ > -static int eta_to_human_short (int64_t secs, char* msg, int maxsize) > +static int eta_to_human_short (unsigned long secs, char* msg) > { > strcpy(msg, "eta: "); > msg += strlen("eta: "); > if (secs < 100) > - snprintf(msg, maxsize, "%"PRId64"s", secs); > + sprintf(msg, "%lus", secs); > else if (secs < 100 * 60) > - snprintf(msg, maxsize, "%"PRId64"m""%"PRId64"s", > - secs / 60, secs % 60); > + sprintf(msg, "%lum%lus", secs / 60, secs % 60); > else if (secs < 48 * 3600) > - snprintf(msg, maxsize, "%"PRId64"h""%"PRId64"m", > - secs / 3600, (secs / 60) % 60); > + sprintf(msg, "%luh%lum", secs / 3600, (secs / 60) % 60); > else if (secs < 100 * 86400) > - snprintf(msg, maxsize, "%"PRId64"d""%"PRId64"h", > - secs / 86400, (secs / 3600) % 24); > + sprintf(msg, "%lud%luh", secs / 86400, (secs / 3600) % 24); > else > sprintf(msg, ">2day"); > return 0; > @@ -378,37 +373,39 @@ static int eta_to_human_short (int64_t secs, char* msg, int maxsize) > void > print_progress(const char *msg, unsigned long current, unsigned long end, struct timeval *start) > { > - float progress; > + unsigned progress; /* in promilles (tenths of a percent) */ > time_t tm; > static time_t last_time = 0; > static unsigned int lapse = 0; > static const char *spinner = "/|\\-"; > struct timeval delta; > - int64_t eta; > - char eta_msg[32] = " "; > + unsigned long eta; > + char eta_msg[16] = " "; > > if (current < end) { > tm = time(NULL); > if (tm - last_time < 1) > return; > last_time = tm; > - progress = (float)current * 100 / end; > + progress = current * 1000 / end; > } else > - progress = 100; > + progress = 1000; > > - if (start != NULL) { > + if (start != NULL && progress != 0) { > calc_delta(start, &delta); > - eta = delta.tv_sec + delta.tv_usec / 1e6; > - eta = (100 - progress) * eta / progress; > - eta_to_human_short(eta, eta_msg, sizeof(eta_msg)); > + eta = 1000 * delta.tv_sec + delta.tv_usec / 1000; > + eta = eta / progress - delta.tv_sec; > + eta_to_human_short(eta, eta_msg); > } > if (flag_ignore_r_char) { > - PROGRESS_MSG("%-" PROGRESS_MAXLEN "s: [%5.1f %%] %c %16s\n", > - msg, progress, spinner[lapse % 4], eta_msg); > + PROGRESS_MSG("%-" PROGRESS_MAXLEN "s: [%3u.%u %%] %c %16s\n", > + msg, progress / 10, progress % 10, > + spinner[lapse % 4], eta_msg); > } else { > PROGRESS_MSG("\r"); > - PROGRESS_MSG("%-" PROGRESS_MAXLEN "s: [%5.1f %%] %c %16s", > - msg, progress, spinner[lapse % 4], eta_msg); > + PROGRESS_MSG("%-" PROGRESS_MAXLEN "s: [%3u.%u %%] %c %16s", > + msg, progress / 10, progress % 10, > + spinner[lapse % 4], eta_msg); > } > lapse++; > } > -- > 2.13.6 > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
