Attachment 218664 Details for Bug 250271 – repro

repro

segv_accerr.c (text/plain), 1.14 KB, created by Emmanuel Vadot on 2020-10-11 12:51:49 UTC

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Creator: Emmanuel Vadot

Created: 2020-10-11 12:51:49 UTC

Size: 1.14 KB

patch

obsolete

>#include <sys/mman.h>
>#include <sys/stat.h>
>#include <err.h>
>#include <fcntl.h>
>#include <unistd.h>
>#include <string.h>
>
>int
>main(int argc, char *argv[])
>{
>	int dir;
>	int fd1, fd2;
>	char *buf1, *buf2;
>	struct stat s1;
>
>	if (argc != 2)
>		errx(1, "Usage: segv_accerr directory");
>
>	dir = open(argv[1], O_DIRECTORY |O_RDONLY|O_CLOEXEC);
>	if (dir == -1)
>		errx(1, "Can't open %s", argv[1]);
>
>	if (fstatat(dir, "file.sample", &s1, 0) == -1) {
>		errx(1, "Can't stat file.sample");
>	}
>
>	fd1 = openat(dir, "file.sample", O_RDONLY);
>	if (fd1 == -1) {
>		errx(1, "Can't open file.sample");
>	}
>	fd2 = openat(dir, "file", O_WRONLY | O_CREAT | O_TRUNC, DEFFILEMODE);
>	if (fd2 == -1) {
>		errx(1, "Can't open file");
>	}
>
>	if (ftruncate(fd2, s1.st_size) != 0) {
>		errx(1, "Can't ftruncate file");
>	}
>	buf1 = mmap(NULL, s1.st_size, PROT_READ, MAP_SHARED, fd1, 0);
>	if (buf1 == NULL) {
>		errx(1, "Can't mmap file.sample");
>	}
>	buf2 = mmap(NULL, s1.st_size, PROT_WRITE, MAP_SHARED, fd2, 0);
>	if (buf2 == NULL) {
>		errx(1, "Can't mmap file");
>	}
>
>	memcpy(buf2, buf1, s1.st_size);
>
>	munmap(buf1, s1.st_size);
>	munmap(buf2, s1.st_size);
>	fsync(fd2);
>
>	close(fd1);
>	close(fd2);
>
>	return (0);
>}

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Attachments on bug 250271: 218664