2019-01-03 18:07:50 |
Matwey V. Kornilov |
description |
Hello,
I am running aarch64-linux-user from master, commit 20d6c7312f1b812bb9c750f4087f69ac8485cc90
And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
Minimal reproducible sample is the following:
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
/*
System | Result
-------------------------+----------------
Native x86_64 4.12.14 | pwrite ret = 0
Native aarch64 4.4.159 | pwrite ret = 0
qemu-aarch64 at x86_64 | pwrite ret = -1
( 20d6c7312f1b8 ) |
*/
int main(int argc, char** argv) {
int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
if (fd < 0) {
perror("open");
return 1;
}
int ret = fallocate(fd, 0, 0, 1000);
if (ret < 0) {
perror("fallocate");
return 1;
}
ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
printf("pwrite ret = %ld\n", ret_pwrite);
close(fd);
return 0;
} |
Hello,
I am running aarch64-linux-user from master, commit 20d6c7312f1b812bb9c750f4087f69ac8485cc90
And I've found the following inconsistent emulation of pwrite() call when buf==NULL and len=0.
Minimal reproducible sample is the following:
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
/*
System | Result
-------------------------+----------------
Native x86_64 4.12.14 | pwrite ret = 0
Native aarch64 4.4.159 | pwrite ret = 0
qemu-aarch64 at x86_64 | pwrite ret = -1
( 20d6c7312f1b8 ) |
*/
int main(int argc, char** argv) {
int fd = open("test.dat", O_CREAT | O_RDWR, 0644);
if (fd < 0) {
perror("open");
return 1;
}
int ret = fallocate(fd, 0, 0, 1000);
if (ret < 0) {
perror("fallocate");
return 1;
}
ssize_t ret_pwrite = pwrite(fd, NULL, 0, 0);
printf("pwrite ret = %ld\n", ret_pwrite);
close(fd);
return 0;
}
Please note, that the same binary executable prints different output at native aarch64 platform and under aarch64-linux-user |
|