vasilito
b9874d0941
Add redbear-usb-storage-check in-guest binary that validates USB mass storage read and write I/O: discovers /scheme/disk/ devices, writes a test pattern to sector 2048, reads it back, verifies match, restores original content. Updates test-usb-storage-qemu.sh with write-proof verification step. Includes all accumulated Red Bear OS work: kernel patches, relibc patches, driver infrastructure, DRM/GPU, KDE recipes, firmware, validation tooling, build system hardening, and documentation.
104 lines
3.2 KiB
C
104 lines
3.2 KiB
C
// copied from autoconf mmap test, currently panicking kernel
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/* Thanks to Mike Haertel and Jim Avera for this test.
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Here is a matrix of mmap possibilities:
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mmap private not fixed
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mmap private fixed at somewhere currently unmapped
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mmap private fixed at somewhere already mapped
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mmap shared not fixed
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mmap shared fixed at somewhere currently unmapped
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mmap shared fixed at somewhere already mapped
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For private mappings, we should verify that changes cannot be read()
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back from the file, nor mmap's back from the file at a different
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address. (There have been systems where private was not correctly
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implemented like the infamous i386 svr4.0, and systems where the
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VM page cache was not coherent with the file system buffer cache
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like early versions of FreeBSD and possibly contemporary NetBSD.)
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For shared mappings, we should conversely verify that changes get
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propagated back to all the places they're supposed to be.
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Grep wants private fixed already mapped.
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The main things grep needs to know about mmap are:
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* does it exist and is it safe to write into the mmap'd area
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* how to use it (BSD variants) */
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <sys/mman.h>
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int
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main (void)
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{
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char *data, *data2, *data3;
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const char *cdata2;
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int i, pagesize;
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int fd, fd2;
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pagesize = sysconf(_SC_PAGESIZE);
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/* First, make a file with some known garbage in it. */
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data = (char *) malloc (pagesize);
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if (!data)
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return 1;
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for (i = 0; i < pagesize; ++i)
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*(data + i) = rand ();
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umask (0);
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fd = creat ("conftest.mmap", 0600);
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if (fd < 0)
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return 2;
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if (write (fd, data, pagesize) != pagesize)
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return 3;
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close (fd);
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/* Next, check that the tail of a page is zero-filled. File must have
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non-zero length, otherwise we risk SIGBUS for entire page. */
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fd2 = open ("conftest.txt", O_RDWR | O_CREAT | O_TRUNC, 0600);
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if (fd2 < 0)
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return 4;
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cdata2 = "";
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if (write (fd2, cdata2, 1) != 1)
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return 5;
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data2 = (char *) mmap (0, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd2, 0L);
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if (data2 == MAP_FAILED)
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return 6;
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for (i = 0; i < pagesize; ++i)
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if (*(data2 + i))
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return 7;
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close (fd2);
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if (munmap (data2, pagesize))
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return 8;
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/* Next, try to mmap the file at a fixed address which already has
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something else allocated at it. If we can, also make sure that
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we see the same garbage. */
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fd = open ("conftest.mmap", O_RDWR);
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if (fd < 0)
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return 9;
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if (data2 != mmap (data2, pagesize, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_FIXED, fd, 0L))
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return 10;
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for (i = 0; i < pagesize; ++i)
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if (*(data + i) != *(data2 + i))
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return 11;
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/* Finally, make sure that changes to the mapped area do not
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percolate back to the file as seen by read(). (This is a bug on
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some variants of i386 svr4.0.) */
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for (i = 0; i < pagesize; ++i)
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*(data2 + i) = *(data2 + i) + 1;
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data3 = (char *) malloc (pagesize);
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if (!data3)
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return 12;
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if (read (fd, data3, pagesize) != pagesize)
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return 13;
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for (i = 0; i < pagesize; ++i)
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if (*(data + i) != *(data3 + i))
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return 14;
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close (fd);
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free (data);
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free (data3);
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return 0;
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} |