mpz_probab_prime_p crashes?
Hi,
I think I may have come across an error in mpz_probab_prime_p() It seems to
occasionally cause a segmentation fault either when repeatedly run with the
same arguments or with increasing values of the first argument.
I initially came across the bug when I was trying to find the closest primes
> 10^n, 2*10^n or 5*10^n when the program would crash after listing the
first
few dozen/hundred results.
The platform is a 16GB M2 Mac Air.
The test program below, pt3.c is the simplest I could produce to demonstrate
the problem.
The first argument 2011 is the smallest value I found which
caused the error.
When I ran pt3 100 times the for() loop executed between 4 and 4684 times
before crashing.
GMP version 6.2.1
=
Philip:gmp_error philip$ cat pt3.c
#include
#include
#include
int main(void)
{
setbuf(stdout,NULL);
mpz_t test;
for(int n = 1; n <= 1000; n++) {
printf("%4d\n", n);
mpz_init(test);
mpz_set_str(test, "2011", 10);
int res = mpz_probab_prime_p(test, 100);
mpz_clear(test);
if(res != 1)
printf("res = %d\n", res);
}
printf("hmmm, it hasn't failed\n");
}
Philip:gmp_error philip$
=
Philip:gmp_error philip$ cc -v
Apple clang version 14.0.3 (clang-1403.0.22.14.1)
Target: arm64-apple-darwin22.5.0
Thread model: posix
InstalledDir:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Philip:gmp_error philip$
=
Philip:gmp_error philip$ uname -a
Darwin Philip 22.5.0 Darwin Kernel Version 22.5.0: Mon Apr 24 20:52:43 PDT
2023; root:xnu-8796.121.2~5/RELEASE_ARM64_T8112 arm64
Philip:gmp_error philip$
=
Philip:gmp-6.2.1 philip$ ./config.guess
aarch64-apple-darwin22.5.0
Philip:gmp-6.2.1 philip$
=
Philip:gmp-6.2.1 philip$ ./configfsf.guess
aarch64-apple-darwin22.5.0
Philip:gmp-6.2.1 philip$
=
Philip:gmp_error philip$ cc -o pt3 pt3.c -lgmp
Philip:gmp_error philip$ ./pt3
1
2
3
4
⋮
143
144
145
146
Segmentation fault: 11
Philip:gmp_error philip$
=
If there's anything I can do to help please ask.
TTFN
Philip Riebold
Philip:gmp-6.2.1 philip$ ./configure
checking build system type... aarch64-apple-darwin22.5.0
checking host system type... aarch64-apple-darwin22.5.0
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... ./install-sh -c -d
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking whether to enable maintainer-specific portions of Makefiles... no
checking ABI=64
checking compiler gcc -O2 -pedantic ... yes
checking compiler gcc -O2 -pedantic has sizeof(void*)==8... yes
checking compiler gcc -O2 -pedantic -march=armv8-a... yes
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking for gcc option to accept ISO C99... none needed
checking how to run the C preprocessor... gcc -E
checking build system compiler gcc... yes
checking for build system preprocessor... gcc -E
checking for build system executable suffix...
checking whether build system compiler is ANSI... yes
checking for build system compiler math library... -lm
checking for grep that handles long lines and -e... /usr/bin/grep
checking for egrep... /usr/bin/grep -E
using ABI="64"
CC="gcc"
CFLAGS="-O2 -pedantic -march=armv8-a"
CPPFLAGS=""
MPN_PATH=" arm64 generic"
checking whether assembler supports --noexecstack option... no
checking for ar... ar
checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
checking the name lister (/usr/bin/nm -B) interface... BSD nm
checking how to print strings... printf
checking for a sed that does not truncate output... /opt/local/bin/gsed
checking for fgrep... /usr/bin/grep -F
checking for ld used by gcc...
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld
checking if the linker
(/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld)
is GNU ld... no
checking whether ln -s works... yes
checking the maximum length of command line arguments... 786432
checking how to convert aarch64-apple-darwin22.5.0 file names to
aarch64-apple-darwin22.5.0 format... func_convert_file_noop
checking how to convert aarch64-apple-darwin22.5.0 file names to toolchain
format... f
Re: mpz_probab_prime_p crashes?
Philip Riebold writes: The test program below, pt3.c is the simplest I could produce to demonstrate the problem. If that simple program would trigger a genuine GMP bug, that would be astonishing indeed. I have no idea why your computer gets a segfault. Perhaps the malloc implementation is completely broken? Perhaps you hit bad RAM cells? -- Torbjörn Please encrypt, key id 0xC8601622 ___ gmp-bugs mailing list gmp-bugs@gmplib.org https://gmplib.org/mailman/listinfo/gmp-bugs
Re: mpz_probab_prime_p crashes?
Hello,
could you try with a recent snapshot from
https://gmplib.org/download/snapshot/ ?
If you built GMP yourself, did you run `make check` afterwards?
On Thu, 8 Jun 2023, Philip Riebold wrote:
Hi,
I think I may have come across an error in mpz_probab_prime_p() It seems to
occasionally cause a segmentation fault either when repeatedly run with the
same arguments or with increasing values of the first argument.
I initially came across the bug when I was trying to find the closest primes
10^n, 2*10^n or 5*10^n when the program would crash after listing the
first
few dozen/hundred results.
The platform is a 16GB M2 Mac Air.
The test program below, pt3.c is the simplest I could produce to demonstrate
the problem.
The first argument 2011 is the smallest value I found which
caused the error.
When I ran pt3 100 times the for() loop executed between 4 and 4684 times
before crashing.
GMP version 6.2.1
=
Philip:gmp_error philip$ cat pt3.c
#include
#include
#include
int main(void)
{
setbuf(stdout,NULL);
mpz_t test;
for(int n = 1; n <= 1000; n++) {
printf("%4d\n", n);
mpz_init(test);
mpz_set_str(test, "2011", 10);
int res = mpz_probab_prime_p(test, 100);
mpz_clear(test);
if(res != 1)
printf("res = %d\n", res);
}
printf("hmmm, it hasn't failed\n");
}
Philip:gmp_error philip$
=
Philip:gmp_error philip$ cc -v
Apple clang version 14.0.3 (clang-1403.0.22.14.1)
Target: arm64-apple-darwin22.5.0
Thread model: posix
InstalledDir:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Philip:gmp_error philip$
=
Philip:gmp_error philip$ uname -a
Darwin Philip 22.5.0 Darwin Kernel Version 22.5.0: Mon Apr 24 20:52:43 PDT
2023; root:xnu-8796.121.2~5/RELEASE_ARM64_T8112 arm64
Philip:gmp_error philip$
=
Philip:gmp-6.2.1 philip$ ./config.guess
aarch64-apple-darwin22.5.0
Philip:gmp-6.2.1 philip$
=
Philip:gmp-6.2.1 philip$ ./configfsf.guess
aarch64-apple-darwin22.5.0
Philip:gmp-6.2.1 philip$
=
Philip:gmp_error philip$ cc -o pt3 pt3.c -lgmp
Philip:gmp_error philip$ ./pt3
1
2
3
4
⋮
143
144
145
146
Segmentation fault: 11
Philip:gmp_error philip$
=
If there's anything I can do to help please ask.
TTFN
Philip Riebold
--
Marc Glisse
___
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