patches/ruby/fix-get_main_stack.patch

   1 diff --git a/thread_pthread.c b/thread_pthread.c
   2 index 951885ffa0..cf90321d1d 100644
   3 --- a/thread_pthread.c
   4 +++ b/thread_pthread.c
   5 @@ -530,9 +530,6 @@ hpux_attr_getstackaddr(const pthread_attr_t *attr, void **addr)
   6  #   define MAINSTACKADDR_AVAILABLE 0
   7  # endif
   8  #endif
   9 -#if MAINSTACKADDR_AVAILABLE && !defined(get_main_stack)
  10 -# define get_main_stack(addr, size) get_stack(addr, size)
  11 -#endif
  12
  13  #ifdef STACKADDR_AVAILABLE
  14  /*
  15 @@ -614,6 +611,55 @@ get_stack(void **addr, size_t *size)
  16      return 0;
  17  #undef CHECK_ERR
  18  }
  19 +
  20 +#if defined(__linux__) && !defined(__GLIBC__) && defined(HAVE_GETRLIMIT)
  21 +
  22 +#ifndef PAGE_SIZE
  23 +#include <unistd.h>
  24 +#define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
  25 +#endif
  26 +
  27 +static int
  28 +get_main_stack(void **addr, size_t *size)
  29 +{
  30 +    size_t start, end, limit, prevend = 0;
  31 +    struct rlimit r;
  32 +    FILE *f;
  33 +    char buf[PATH_MAX+80], s[8];
  34 +    int n;
  35 +    STACK_GROW_DIR_DETECTION;
  36 +
  37 +    f = fopen("/proc/self/maps", "re");
  38 +    if (!f)
  39 +        return -1;
  40 +    n = 0;
  41 +    while (fgets(buf, sizeof buf, f)) {
  42 +        n = sscanf(buf, "%zx-%zx %*s %*s %*s %*s %7s", &start, &end, s);
  43 +        if (n >= 2) {
  44 +            if (n == 3 && strcmp(s, "[stack]") == 0)
  45 +                break;
  46 +            prevend = end;
  47 +        }
  48 +        n = 0;
  49 +    }
  50 +    fclose(f);
  51 +    if (n == 0)
  52 +        return -1;
  53 +
  54 +    limit = 100 << 20; /* 100MB stack limit */
  55 +    if (getrlimit(RLIMIT_STACK, &r)==0 && r.rlim_cur < limit)
  56 +        limit = r.rlim_cur & -PAGE_SIZE;
  57 +    if (limit > end) limit = end;
  58 +    if (prevend < end - limit) prevend = end - limit;
  59 +    if (start > prevend) start = prevend;
  60 +    *addr = IS_STACK_DIR_UPPER() ? (void *)start : (void *)end;
  61 +    *size = end - start;
  62 +    return 0;
  63 +}
  64 +#else
  65 +# define get_main_stack(addr, size) get_stack(addr, size)
  66 +#endif
  67 +
  68  #endif
  69
  70  static struct {