toolchain/uClibc/patches/001-fix_mmap.patch

   1 --- /dev/null
   2 +++ b/test/mmap/mmap2.c
   3 @@ -0,0 +1,41 @@
   4 +/* When trying to map /dev/mem with offset 0xFFFFF000 on the ARM platform, mmap
   5 + * returns -EOVERFLOW.
   6 + *
   7 + * Since off_t is defined as a long int and the sign bit is set in the address,
   8 + * the shift operation shifts in ones instead of zeroes
   9 + * from the left. This results the offset sent to the kernel function becomes
  10 + * 0xFFFFFFFF instead of 0x000FFFFF with MMAP2_PAGE_SHIFT set to 12.
  11 + */
  12 +
  13 +#include <unistd.h>
  14 +#include <stdio.h>
  15 +#include <stdlib.h>
  16 +#include <string.h>
  17 +#include <errno.h>
  18 +#include <fcntl.h>
  19 +#include <sys/mman.h>
  20 +
  21 +#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \
  22 +  __LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)
  23 +
  24 +#define MAP_SIZE 4096UL
  25 +#define MAP_MASK (MAP_SIZE - 1)
  26 +
  27 +int main(int argc, char **argv) {
  28 +    void* map_base = 0;
  29 +    int fd;
  30 +    off_t target = 0xfffff000;
  31 +    if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) FATAL;
  32 +    printf("/dev/mem opened.\n");
  33 +    fflush(stdout);
  34 +
  35 +   /* Map one page */
  36 +    map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
  37 +                        fd, target & ~MAP_MASK);
  38 +    if(map_base == (void *) -1) FATAL;
  39 +    printf("Memory mapped at address %p.\n", map_base);
  40 +    fflush(stdout);
  41 +    if(munmap(map_base, MAP_SIZE) == -1) FATAL;
  42 +    close(fd);
  43 +    return 0;
  44 +}
  45 --- a/libc/sysdeps/linux/arm/mmap.c
  46 +++ b/libc/sysdeps/linux/arm/mmap.c
  47 @@ -27,7 +27,6 @@ __ptr_t mmap(__ptr_t addr, size_t len, i
  48
  49  #elif defined  (__NR_mmap2)
  50  #define __NR__mmap __NR_mmap2
  51 -
  52  #ifndef MMAP2_PAGE_SHIFT
  53  # define MMAP2_PAGE_SHIFT 12
  54  #endif
  55 @@ -39,9 +38,17 @@ __ptr_t mmap(__ptr_t addr, size_t len, i
  56  {
  57    /* check if offset is page aligned */
  58      if (offset & ((1 << MMAP2_PAGE_SHIFT) - 1))
  59 +    {
  60 +        __set_errno(EINVAL);
  61          return MAP_FAILED;
  62 +    }
  63 +#ifdef __USE_FILE_OFFSET64
  64 +  return (__ptr_t) _mmap (addr, len, prot, flags,
  65 +                                                 fd,((__u_quad_t) offset >> MMAP2_PAGE_SHIFT));
  66 +#else
  67    return (__ptr_t) _mmap (addr, len, prot, flags,
  68 -                                                 fd,(off_t) (offset >> MMAP2_PAGE_SHIFT));
  69 +                          fd,((__u_long) offset >> MMAP2_PAGE_SHIFT));
  70 +#endif
  71  }
  72  #elif defined (__NR_mmap)
  73  # define __NR__mmap __NR_mmap
  74 --- a/libc/sysdeps/linux/common/mmap64.c
  75 +++ b/libc/sysdeps/linux/common/mmap64.c
  76 @@ -58,8 +58,13 @@ __ptr_t mmap64(__ptr_t addr, size_t len,
  77                 __set_errno(EINVAL);
  78                 return MAP_FAILED;
  79         }
  80 -
  81 -       return __syscall_mmap2(addr, len, prot, flags, fd, (off_t) (offset >> MMAP2_PAGE_SHIFT));
  82 +#ifdef __USE_FILE_OFFSET64
  83 +  return __syscall_mmap2(addr, len, prot, flags,
  84 +                         fd,((__u_quad_t)offset >> MMAP2_PAGE_SHIFT));
  85 +#else
  86 +   return __syscall_mmap2(addr, len, prot, flags,
  87 +                          fd,((__u_long)offset >> MMAP2_PAGE_SHIFT));
  88 +#endif
  89  }
  90
  91  # endif