Hi Erik,
On May 12 15:30, Erik Bray wrote:
> Hi all,
>
> This issue pertains to Cygwin 64-bit. The following example program
> demonstrates the issue:
>
> $ cat mmap_test.c
> #include <sys/mman.h>
> #include <stdio.h>
> #include <windows.h>
>
>
> #define VSIZE 0x100001000
> #define SIZE 0x1000
>
>
> void foo() {
> void *top, *bot, *c;
>
> c = mmap(NULL, VSIZE, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0);
>
> top = c + VSIZE;
> bot = top - SIZE;
>
> printf(" c = 0x%016lx\n", c);
> printf(" top = 0x%016lx\n", top);
> printf(" bot = 0x%016lx\n", bot);
>
> printf(" c[0] = %ul\n", *((unsigned long *)c));
> printf("bot[0] = %ul\n", *((unsigned long *)bot));
> }
>
>
> int main(void) {
> foo();
> return 0;
> }
>
> $ gcc mmap_test.c -o mmap_test
>
> $ ./mmap_test.exe
> c = 0x000006feffff0000
> top = 0x000006ffffff1000
> bot = 0x000006ffffff0000
> c[0] = 0l
> Segmentation fault (core dumped)
>
> --------------------------------------------------Thanks especially for the testcase. I just applied a fix for this which, hopefully, catches all problems with too small length/size variables and parameters. I've uploaded a new developer snapshot to https://cygwin.com/snapshots/ Would you mind to inspect the patch(*) critically? Thanks a lot, Corinna (*) https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=commitdiff;h=0aa738220bb9dea2ad479e484560767b36701947 -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
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