[Mono-dev] mmap problem
buhochileno at gmail.com
buhochileno at gmail.com
Tue Oct 30 12:27:39 EDT 2007
Thank you Jonathan for all your patience and help...
Jonathan Pryor wrote:
> On Mon, 2007-10-29 at 20:28 -0300, buhochileno at gmail.com wrote:
>
>> About the gdb test, this is my result:
>>
>> //I don't pass the /pr.txt file as parameter, internally I open allways
>> this file
>> (gdb) b Mono_Posix_Syscall_mmap
>> Function "Mono_Posix_Syscall_mmap" not defined.
>> Make breakpoint pending on future shared library load? (y or [n]) y
>>
>> Breakpoint 1 (Mono_Posix_Syscall_mmap) pending.
>> (gdb) r pr1mmap.exe
>> Starting program: /usr/bin/mono pr1mmap.exe
>> Reading symbols from shared object read from target memory...done.
>> Loaded system supplied DSO at 0x4ff000
>> [Thread debugging using libthread_db enabled]
>> [New Thread 2311872 (LWP 26956)]
>> [New Thread 5647264 (LWP 26973)]
>> [New Thread 5200800 (LWP 26974)]
>> Breakpoint 2 at 0xd37cc3: file sys-mman.c, line 27.
>> Pending breakpoint "Mono_Posix_Syscall_mmap" resolved
>> fstat ok
>> length = 6
>> [Switching to Thread 2311872 (LWP 26956)]
>>
>> Breakpoint 2, Mono_Posix_Syscall_mmap (start=0x6, length=6, prot=6, flags=6,
>> fd=6, offset=0) at sys-mman.c:27
>> 27 mph_return_val_if_size_t_overflow (length, MAP_FAILED);
>> (gdb) n
>> 24 {
>> (gdb) n
>> 27 mph_return_val_if_size_t_overflow (length, MAP_FAILED);
>> (gdb) n
>> 28 mph_return_val_if_off_t_overflow (offset, MAP_FAILED);
>> (gdb) n
>> 36 }
>>
>
> This is the important difference -- you never hit
> Mono_Posix_FromMmapProts(), but instead return immediately after the
> offset check. Which implies that gcc thinks that 0 won't fit within an
> off_t, which is...weird.
>
>
>> The little diference that I can see from your result is the prot=6,
>> flags=6, in your case is 1 and 2 values.
>>
>
> This just illustrates different flags we're passing to Syscall.mmap().
> I passed MmapProts.PROT_READ (1), while you presumably passed
> MmapProts.PROT_EXEC|MmapProts.PROT_WRITE (6), and I passed
> MmapFlags.MAP_PRIVATE (2) while you presumably passed...I have no idea
> what you passed for `flags', as no flag has the value 0x04. :-/
>
>
nop, I pass the same flags as you example code:
start = Syscall.mmap ( IntPtr.Zero, (ulong)len, MmapProts.PROT_READ,
MmapFlags.MAP_PRIVATE, fdin,0);
> Going back to the weirdness of mph_return_val_if_off_t_overflow()
> failing 0... Compile the attached program as:
>
> gcc -DHAVE_LARGE_FILE_SUPPORT=1 -DSIZEOF_SIZE_T=4 off_t-ovf.c \
> -o off_t-ovf `pkg-config --cflags --libs glib-2.0`
>
> Then execute ./off_t-ovf and send me the output.
>
overflow? 0
> You might also try building your own copy of Mono; see:
>
> http://www.mono-project.com/Parallel_Mono_Environments
>
> This may come in handy because if off_t-ovf works successfully (which I
> fully expect it to), I'll need to resort to reading the <config.h> file
> generated by Mono's configure script...which won't be included with
> Fedora's install. :-/
>
> - Jon
>
>
Ok, I start to checkout the last svn version of mono and build a
parallel mono installation
Thanks again
Mauricio
> ------------------------------------------------------------------------
>
> /*
> * Common/shared macros and routines.
> *
> * This file contains macros of the form
> *
> * mph_return_if_TYPE_overflow(val);
> *
> * Which tests `val' for a TYPE underflow/overflow (that is, is `val' within
> * the range for TYPE?). If `val' can't fit in TYPE, errno is set to
> * EOVERFLOW, and `return -1' is executed (which is why it's a macro).
> *
> * Assumptions:
> *
> * I'm working from GLibc, so that's the basis for my assumptions. They may
> * not be completely portable, in which case I'll need to fix my assumptions.
> * :-(
> *
> * See the typedefs for type size assumptions. These typedefs *must* be kept
> * in sync with the types used in Mono.Posix.dll.
> *
> * See also:
> * http://developer.apple.com/documentation/Darwin/Reference/ManPages/
> */
>
> #ifndef INC_mph_H
> #define INC_mph_H
>
> #include <limits.h> /* LONG_MAX, ULONG_MAX */
> #include <errno.h> /* for ERANGE */
> #include <glib.h> /* for g* types, etc. */
>
> #ifdef HAVE_STDINT_H
> #include <stdint.h> /* for SIZE_MAX */
> #endif
>
> #if __APPLE__ || __BSD__ || __FreeBSD__
> #define MPH_ON_BSD
> #endif
>
> #ifdef HAVE_VISIBILITY_HIDDEN
> #define MPH_INTERNAL __attribute__((visibility("hidden")))
> #else
> #define MPH_INTERNAL
> #endif
>
> #if defined (PLATFORM_WIN32) && !defined (EOVERFLOW)
> #define EOVERFLOW 75
> #endif /* def PLATFORM_WIN32 && ndef EOVERFLOW */
>
> #if !defined (PLATFORM_WIN32)
>
> /*
> * Solaris doesn't define these BSD values, and if they're not present then
> * map.c:Mono_Posix_FromSeekFlags() breaks badly; see:
> * http://bugzilla.gnome.org/show_bug.cgi?id=370081
> */
>
> #ifndef L_SET
> #define L_SET SEEK_SET
> #endif /* ndef L_SET */
>
> #ifndef L_INCR
> #define L_INCR SEEK_CUR
> #endif /* ndef L_INCR */
>
> #ifndef L_XTND
> #define L_XTND SEEK_END
> #endif /* ndef L_XTND */
>
> /*
> * XATTR_AUTO is a synonym for 0 within XattrFlags, but most systems don't
> * define it. map.c doesn't know that, though, so we ensure that it's defined
> * so that the value 0 round-trips through MonoPosixHelper.
> */
>
> #ifndef XATTR_AUTO
> #define XATTR_AUTO 0
> #endif /* ndef XATTR_AUTO */
>
> #endif /* ndef PLATFORM_WIN32 */
>
> typedef gint64 mph_blkcnt_t;
> typedef gint64 mph_blksize_t;
> typedef guint64 mph_dev_t;
> typedef guint64 mph_ino_t;
> typedef guint64 mph_nlink_t;
> typedef gint64 mph_off_t;
> typedef guint64 mph_size_t;
> typedef gint64 mph_ssize_t;
> typedef gint32 mph_pid_t;
> typedef guint32 mph_gid_t;
> typedef guint32 mph_uid_t;
> typedef gint64 mph_time_t;
> typedef gint64 mph_clock_t;
> typedef guint64 mph_fsblkcnt_t;
> typedef guint64 mph_fsfilcnt_t;
>
> /* Some versions of OS X don't define these typedefs, needed by map.c */
> #ifndef HAVE_BLKCNT_T
> typedef mph_blkcnt_t blkcnt_t;
> #endif
>
> #ifndef HAVE_BLKSIZE_T
> typedef mph_blksize_t blksize_t;
> #endif
>
> #ifndef HAVE_SUSECONDS_T
> typedef gint64 suseconds_t;
> #endif
>
> #ifdef HAVE_LARGE_FILE_SUPPORT
> #define MPH_OFF_T_MAX G_MAXINT64
> #define MPH_OFF_T_MIN G_MININT64
> #else
> #define MPH_OFF_T_MAX G_MAXINT32
> #define MPH_OFF_T_MIN G_MININT32
> #endif
>
> #ifdef SIZE_MAX
> #define MPH_SIZE_T_MAX SIZE_MAX
> #elif SIZEOF_SIZE_T == 8
> #define MPH_SIZE_T_MAX G_MAXUINT64
> #elif SIZEOF_SIZE_T == 4
> #define MPH_SIZE_T_MAX G_MAXUINT32
> #else
> #error "sizeof(size_t) is unknown!"
> #endif
>
> #define _mph_return_val_if_cb_(val, ret, cb) G_STMT_START{ \
> if (cb (val)) { \
> errno = EOVERFLOW; \
> return ret; \
> }}G_STMT_END
>
> #define mph_have_long_overflow(var) ((var) > LONG_MAX || (var) < LONG_MIN)
>
> #define mph_return_val_if_long_overflow(var, ret) \
> _mph_return_val_if_cb_(var, ret, mph_have_long_overflow)
>
> #define mph_return_if_long_overflow(var) mph_return_val_if_long_overflow(var, -1)
>
> #define mph_have_ulong_overflow(var) ((var) > ULONG_MAX)
>
> #define mph_return_val_if_ulong_overflow(var, ret) \
> _mph_return_val_if_cb_(var, ret, mph_have_ulong_overflow)
>
> #define mph_return_if_ulong_overflow(var) mph_return_val_if_ulong_overflow(var, -1)
>
> #define mph_have_size_t_overflow(var) ((var) > MPH_SIZE_T_MAX)
>
> #define mph_return_val_if_size_t_overflow(var, ret) \
> _mph_return_val_if_cb_(var, ret, mph_have_size_t_overflow)
>
> #define mph_return_val_if_ssize_t_overflow(var, ret) \
> _mph_return_val_if_cb_(var, ret, mph_have_long_overflow)
>
> #define mph_return_if_size_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
>
> #define mph_return_if_ssize_t_overflow(var) mph_return_val_if_ssize_t_overflow(var, -1)
>
> #define mph_have_off_t_overflow(var) \
> (((var) < MPH_OFF_T_MIN) || ((var) > MPH_OFF_T_MAX))
>
> #define mph_return_val_if_off_t_overflow(var, ret) \
> _mph_return_val_if_cb_(var, ret, mph_have_off_t_overflow)
>
> #define mph_return_if_off_t_overflow(var) mph_return_val_if_size_t_overflow(var, -1)
>
> #define mph_return_if_time_t_overflow(var) mph_return_if_long_overflow(var)
>
> #define mph_return_if_val_in_list5(var,a,b,c,d,e) \
> do { \
> int v = (var); \
> if (v == a || v == b || v == c || v == d || v == e) \
> return -1; \
> } while (0)
>
> /*
> * Helper function for functions which use ERANGE (such as getpwnam_r and
> * getgrnam_r). These functions accept buffers which are dynamically
> * allocated so that they're only as large as necessary. However, Linux and
> * Mac OS X differ on how to signal an error value.
> *
> * Linux returns the error value directly, while Mac OS X is more traditional,
> * returning -1 and setting errno accordingly.
> *
> * Unify the checking in one place.
> */
> static inline int
> recheck_range (int ret)
> {
> if (ret == ERANGE)
> return 1;
> if (ret == -1)
> return errno == ERANGE;
> return 0;
> }
>
> MPH_INTERNAL char*
> _mph_copy_structure_strings (
> void *to, const size_t *to_offsets,
> const void *from, const size_t *from_offsets,
> size_t num_strings);
>
> #endif /* ndef INC_mph_H */
>
> #include <stdio.h>
>
> int main ()
> {
> mph_off_t offset = 0;
> printf ("overflow? %i\n", mph_have_off_t_overflow (offset));
> return 0;
> }
>
> /*
> * vim: noexpandtab
> */
>
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