Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-14 Thread David Lee 
On 14 November 2017 at 11:40, Liu Hao  wrote:
> On 2017/11/14 9:58, Liu Hao wrote:
>> On 2017/11/13 11:11, David Lee wrote:
>>> Built and tested a cross compiler (i686-w64-mingw32-gcc 6.4.0) on
>>> debian stretch with master mingw-w64. Same crash.
>>>
>> Yeah I just updated MSYS2's repos and observed the crash... can't imagine 
>> why it didn't crash a few days ago.
>>
>> The patch for mingw_vfscanf.c on SF is a bit complex so let me take a deep 
>> look at it.
>>
>>
>
> AFAICT the C99 standard doesn't treat the format strings of *scanf and w*canf 
> and differently.
> That is, %s always designates a narrow string and %ls always designates a 
> wide string. So are %c and %lc.
>
> Basing on that, I think the fix in 72d60c1a06490ec5937e6c620956b167bf0bf329 
> can be applied cleanly to its wide variant.
> The patch attached is confirmed to fix the crash on x86_64 and i686. Please 
> review.
>

Tried on my cross compiler and the crash went away. Thanks.

I need to test more (e.g. field width + assignment suppression for %s) though.

David Lee.

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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-13 Thread Liu Hao 
On 2017/11/14 9:58, Liu Hao wrote:
> On 2017/11/13 11:11, David Lee wrote:
>> Built and tested a cross compiler (i686-w64-mingw32-gcc 6.4.0) on
>> debian stretch with master mingw-w64. Same crash.
>>
> Yeah I just updated MSYS2's repos and observed the crash... can't imagine why 
> it didn't crash a few days ago.
> 
> The patch for mingw_vfscanf.c on SF is a bit complex so let me take a deep 
> look at it.
> 
> 

AFAICT the C99 standard doesn't treat the format strings of *scanf and w*canf 
and differently.
That is, %s always designates a narrow string and %ls always designates a wide 
string. So are %c and %lc.

Basing on that, I think the fix in 72d60c1a06490ec5937e6c620956b167bf0bf329 can 
be applied cleanly to its wide variant.
The patch attached is confirmed to fix the crash on x86_64 and i686. Please 
review.


-- 
Best regards,
LH_Mouse
From c470391c15e8006c43bc8d3924d1ad44de94ed87 Mon Sep 17 00:00:00 2001
From: Liu Hao 
Date: Tue, 14 Nov 2017 10:16:24 +0800
Subject: [PATCH] stdio/mingw_wvfscanf.c: Fix segmentation fault when a char or
 string format (without malloc option) is used, like
 72d60c1a06490ec5937e6c620956b167bf0bf329.

Signed-off-by: Liu Hao 
---
 mingw-w64-crt/stdio/mingw_wvfscanf.c | 24 +++-
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/mingw-w64-crt/stdio/mingw_wvfscanf.c 
b/mingw-w64-crt/stdio/mingw_wvfscanf.c
index 045aba79..043c19b4 100644
--- a/mingw-w64-crt/stdio/mingw_wvfscanf.c
+++ b/mingw-w64-crt/stdio/mingw_wvfscanf.c
@@ -104,13 +104,19 @@ get_va_nth (va_list argp, unsigned int n)
 }
 
 static void
-optimize_alloc (int do_realloc, char **p, size_t sz, size_t need_sz, size_t 
typ_sz)
+optimize_alloc (char **p, char *end, size_t alloc_sz)
 {
+  size_t need_sz;
   char *h;
 
-  if (!do_realloc || sz == need_sz || !p || *p == NULL)
+  if (!p || !*p)
 return;
-  if ((h = (char *) realloc (*p, need_sz * typ_sz)) != NULL)
+
+  need_sz = end - *p;
+  if (need_sz == alloc_sz)
+return;
+
+  if ((h = (char *) realloc (*p, need_sz)) != NULL)
 *p = h;
 }
 
@@ -629,7 +635,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
 
  if ((flags & IS_SUPPRESSED) == 0)
{
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (str 
- *pstr), sizeof (char));
+ optimize_alloc (pstr, str, str_sz);
  pstr = NULL;
  ++rval;
}
@@ -708,7 +714,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
 
  if ((flags & IS_SUPPRESSED) == 0)
{
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr 
- (wchar_t *) *pstr), sizeof (wchar_t));
+ optimize_alloc (pstr, (char *) wstr, str_sz * sizeof (wchar_t));
  pstr = NULL;
  ++rval;
}
@@ -824,7 +830,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
  }
  *str++ = 0;
 
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (str 
- *pstr), sizeof (char));
+ optimize_alloc (pstr, str, str_sz);
  pstr = NULL;
  ++rval;
}
@@ -903,7 +909,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
{
  *wstr++ = 0;
 
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr 
- (wchar_t *) *pstr), sizeof (wchar_t));
+ optimize_alloc (pstr, (char *) wstr, str_sz * sizeof (wchar_t));
  pstr = NULL;
  ++rval;
}
@@ -1449,7 +1455,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
{
  *wstr++ = 0;
 
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, 
(wstr - (wchar_t *) *pstr), sizeof (wchar_t));
+ optimize_alloc (pstr, (char *) wstr, str_sz * sizeof 
(wchar_t));
  pstr = NULL;
  ++rval;
}
@@ -1581,7 +1587,7 @@ __mingw_swformat (_IFP *s, const wchar_t *format, va_list 
argp)
  }
  *str++ = 0;
 
- optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, 
(str - *pstr), sizeof (char));
+ optimize_alloc (pstr, str, str_sz);
  pstr = NULL;
  ++rval;
}
-- 
2.14.2

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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-13 Thread Liu Hao 

On 2017/11/13 11:11, David Lee wrote:

Built and tested a cross compiler (i686-w64-mingw32-gcc 6.4.0) on
debian stretch with master mingw-w64. Same crash.

Yeah I just updated MSYS2's repos and observed the crash... can't 
imagine why it didn't crash a few days ago.


The patch for mingw_vfscanf.c on SF is a bit complex so let me take a 
deep look at it.



--
Best regards,
LH_Mouse


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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-12 Thread David Lee 
On 12 November 2017 at 15:28, David Lee  wrote:
> On 11 November 2017 at 21:47, Hannes Domani via Mingw-w64-public
>  wrote:
>> Am Samstag, 11. November 2017, 10:15:00 MEZ hat Liu Hao  
>> Folgendes geschrieben:
>>
>>> Debugging in assembly exposes indirection through a null pointer in
>>> `mingw-w64-crt/stdio/mingw_wvfscanf.c` around or after line 906:
>>>
>>> ```
>>> optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr -
>>> (wchar_t *) *pstr), sizeof (wchar_t));`
>>> ```
>>
>> pstr==NULL, so the *pstr part crashes.
>>
>>> The CRT libraries of those toolchains were not compiled with debug
>>> information. Further investigation might not be possible.
>>>
>>> I am not able to reproducible this problem on master. You might want to
>>> try a newer version and see if the problem still exists.
>>
>> It doesn't look fixed on master, mingw_wvfscanf.c is the same in v5.x and 
>> master.
>>
>> But as far as I can tell this was fixed in mingw_vfscanf in here:
>> https://sourceforge.net/p/mingw-w64/mailman/message/27912175/
>> https://sourceforge.net/p/mingw-w64/mingw-w64/ci/72d60c1a06490ec5937e6c620956b167bf0bf329/
>>
>> There is even the suggestion that mingw_wvfscanf.c might need a similar fix, 
>> which was never done.
>>
>
> Looks like the fix was in mingw_vfscanf.c but not in mingw_wvfscanf.c.
> optimize_alloc() looks different in each file.
>
> I'll try building a GCC with master mingw-w64, test it and see what happens.
>

Built and tested a cross compiler (i686-w64-mingw32-gcc 6.4.0) on
debian stretch with master mingw-w64. Same crash.

David Lee.

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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-11 Thread David Lee 
On 11 November 2017 at 21:47, Hannes Domani via Mingw-w64-public
 wrote:
> Am Samstag, 11. November 2017, 10:15:00 MEZ hat Liu Hao  
> Folgendes geschrieben:
>
>> Debugging in assembly exposes indirection through a null pointer in
>> `mingw-w64-crt/stdio/mingw_wvfscanf.c` around or after line 906:
>>
>> ```
>> optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr -
>> (wchar_t *) *pstr), sizeof (wchar_t));`
>> ```
>
> pstr==NULL, so the *pstr part crashes.
>
>> The CRT libraries of those toolchains were not compiled with debug
>> information. Further investigation might not be possible.
>>
>> I am not able to reproducible this problem on master. You might want to
>> try a newer version and see if the problem still exists.
>
> It doesn't look fixed on master, mingw_wvfscanf.c is the same in v5.x and 
> master.
>
> But as far as I can tell this was fixed in mingw_vfscanf in here:
> https://sourceforge.net/p/mingw-w64/mailman/message/27912175/
> https://sourceforge.net/p/mingw-w64/mingw-w64/ci/72d60c1a06490ec5937e6c620956b167bf0bf329/
>
> There is even the suggestion that mingw_wvfscanf.c might need a similar fix, 
> which was never done.
>

Looks like the fix was in mingw_vfscanf.c but not in mingw_wvfscanf.c.
optimize_alloc() looks different in each file.

I'll try building a GCC with master mingw-w64, test it and see what happens.

David Lee.

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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-11 Thread Liu Hao 

On 2017/11/11 21:47, Hannes Domani via Mingw-w64-public wrote:

Am Samstag, 11. November 2017, 10:15:00 MEZ hat Liu Hao  
Folgendes geschrieben:


Debugging in assembly exposes indirection through a null pointer in
`mingw-w64-crt/stdio/mingw_wvfscanf.c` around or after line 906:

```
optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr -
(wchar_t *) *pstr), sizeof (wchar_t));`
```


pstr==NULL, so the *pstr part crashes.


No, on the master branch it does not crash.




The CRT libraries of those toolchains were not compiled with debug
information. Further investigation might not be possible.

I am not able to reproducible this problem on master. You might want to
try a newer version and see if the problem still exists.


It doesn't look fixed on master, mingw_wvfscanf.c is the same in v5.x and 
master.

But as far as I can tell this was fixed in mingw_vfscanf in here:
https://sourceforge.net/p/mingw-w64/mailman/message/27912175/
https://sourceforge.net/p/mingw-w64/mingw-w64/ci/72d60c1a06490ec5937e6c620956b167bf0bf329/

There is even the suggestion that mingw_wvfscanf.c might need a similar fix, 
which was never done.



Do it today? I just can't reproduce the problem so I can't test it. Sorry.


--
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LH_Mouse


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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-11 Thread Hannes Domani via Mingw-w64-public 
Am Samstag, 11. November 2017, 10:15:00 MEZ hat Liu Hao  
Folgendes geschrieben:

> Debugging in assembly exposes indirection through a null pointer in
> `mingw-w64-crt/stdio/mingw_wvfscanf.c` around or after line 906:
> 
> ```
> optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr -
> (wchar_t *) *pstr), sizeof (wchar_t));`
> ```

pstr==NULL, so the *pstr part crashes.

> The CRT libraries of those toolchains were not compiled with debug
> information. Further investigation might not be possible.
> 
> I am not able to reproducible this problem on master. You might want to
> try a newer version and see if the problem still exists.

It doesn't look fixed on master, mingw_wvfscanf.c is the same in v5.x and 
master.

But as far as I can tell this was fixed in mingw_vfscanf in here:
https://sourceforge.net/p/mingw-w64/mailman/message/27912175/
https://sourceforge.net/p/mingw-w64/mingw-w64/ci/72d60c1a06490ec5937e6c620956b167bf0bf329/

There is even the suggestion that mingw_wvfscanf.c might need a similar fix, 
which was never done.

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Re: [Mingw-w64-public] swscanf() crashes if __USE_MINGW_ANSI_STDIO is defined

2017-11-11 Thread Liu Hao 

On 2017/11/11 12:41, David Lee wrote:

Hello,

Tried to compile and run the following C code on Windows (with
gcc/mingw-w64), and it crashed at the swscanf() call:



#define __USE_MINGW_ANSI_STDIO 1

#include 

int
main(void)
{
 wchar_t buf[] = L"1 2 3";
 wchar_t field[10];

 swscanf(buf, L"%ls", field); // crash
 wprintf(L"%ls\n", field);

 return 0;
}



This is not my original code. The original code is C++ which includes
a C++ header  which indirectly defines __USE_MINGW_ANSI_STDIO
(after multiple levels of includes), so originally I didn't define
this constant myself. At least the code here doesn't have C++
influences.

I assumed that, if __USE_MINGW_ANSI_STDIO is defined to be 1, then the
Microsoft convention of interpreting %s" is suppressed and C99
convention rules. It applies to *printf() so I assumed it applies to
*scanf() as well. Instead the program crashed.

The swscanf() call still crashed with different specifiers: "%s", and "%S"

The compiler used were downloaded from here (5.4.0 and 6.4.0)

https://sourceforge.net/projects/mingw-w64/files/Multilib%20Toolchains%28Targetting%20Win32%20and%20Win64%29/



Regards,

David Lee.



Debugging in assembly exposes indirection through a null pointer in 
`mingw-w64-crt/stdio/mingw_wvfscanf.c` around or after line 906:


```
optimize_alloc ((flags & IS_ALLOC_USED) != 0, pstr, str_sz, (wstr - 
(wchar_t *) *pstr), sizeof (wchar_t));`

```

The CRT libraries of those toolchains were not compiled with debug 
information. Further investigation might not be possible.


I am not able to reproducible this problem on master. You might want to 
try a newer version and see if the problem still exists.


--
Best regards,
LH_Mouse


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