Re: [PATCH v2 1/1] Cygwin: console: Revive Win7 compatibility.
On Thu, 2019-09-19 at 05:49 +0900, Takashi Yano wrote:
> - The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7
> compatibility. This patch fixes the issue.
> ---
> winsup/cygwin/fhandler.h | 6 ++
> winsup/cygwin/fhandler_console.cc | 6 --
> winsup/cygwin/select.cc | 1 -
> 3 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
> index 4efb6a4f2..94b0e520b 100644
> --- a/winsup/cygwin/fhandler.h
> +++ b/winsup/cygwin/fhandler.h
> @@ -43,6 +43,12 @@ details. */
>
> #define O_TMPFILE_FILE_ATTRS (FILE_ATTRIBUTE_TEMPORARY |
> FILE_ATTRIBUTE_HIDDEN)
>
> +/* Buffer size for ReadConsoleInput() and PeakConsoleInput(). */
> +/* Per MSDN, max size of buffer required is below 64K. */
> +/* (65536 / sizeof (INPUT_RECORD)) is 3276, however,
> + ERROR_NOT_ENOUGH_MEMORY occurs in win7 if this value is used. */
> +#define INREC_SIZE 2048
> +
Would it make sense to define this using wincap so it is 2048 for
Win7/2K8 and 3276 for newer versions?
> extern const char *windows_device_names[];
> extern struct __cygwin_perfile *perfile_table;
> #define __fmode (*(user_data->fmode_ptr))
> diff --git a/winsup/cygwin/fhandler_console.cc
> b/winsup/cygwin/fhandler_console.cc
> index 709b8255d..86c39db25 100644
> --- a/winsup/cygwin/fhandler_console.cc
> +++ b/winsup/cygwin/fhandler_console.cc
> @@ -499,9 +499,6 @@ fhandler_console::process_input_message (void)
>
>termios *ti = &(get_ttyp ()->ti);
>
> - /* Per MSDN, max size of buffer required is below 64K. */
> -#defineINREC_SIZE(65536 / sizeof (INPUT_RECORD))
> -
>fhandler_console::input_states stat = input_processing;
>DWORD total_read, i;
>INPUT_RECORD input_rec[INREC_SIZE];
> @@ -1165,9 +1162,6 @@ fhandler_console::ioctl (unsigned int cmd, void *arg)
> return -1;
>case FIONREAD:
> {
> - /* Per MSDN, max size of buffer required is below 64K. */
> -#defineINREC_SIZE(65536 / sizeof (INPUT_RECORD))
> -
> DWORD n;
> int ret = 0;
> INPUT_RECORD inp[INREC_SIZE];
> diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
> index ed8c98d1c..e7014422b 100644
> --- a/winsup/cygwin/select.cc
> +++ b/winsup/cygwin/select.cc
> @@ -1209,7 +1209,6 @@ peek_pty_slave (select_record *s, bool from_select)
> {
> if (ptys->is_line_input ())
> {
> -#define INREC_SIZE (65536 / sizeof (INPUT_RECORD))
> INPUT_RECORD inp[INREC_SIZE];
> DWORD n;
> PeekConsoleInput (ptys->get_handle (), inp, INREC_SIZE, );
--
Yaakov Selkowitz
Senior Software Engineer - Platform Enablement
Red Hat, Inc.
[PATCH v2 1/1] Cygwin: console: Revive Win7 compatibility.
- The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7
compatibility. This patch fixes the issue.
---
winsup/cygwin/fhandler.h | 6 ++
winsup/cygwin/fhandler_console.cc | 6 --
winsup/cygwin/select.cc | 1 -
3 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 4efb6a4f2..94b0e520b 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -43,6 +43,12 @@ details. */
#define O_TMPFILE_FILE_ATTRS (FILE_ATTRIBUTE_TEMPORARY | FILE_ATTRIBUTE_HIDDEN)
+/* Buffer size for ReadConsoleInput() and PeakConsoleInput(). */
+/* Per MSDN, max size of buffer required is below 64K. */
+/* (65536 / sizeof (INPUT_RECORD)) is 3276, however,
+ ERROR_NOT_ENOUGH_MEMORY occurs in win7 if this value is used. */
+#define INREC_SIZE 2048
+
extern const char *windows_device_names[];
extern struct __cygwin_perfile *perfile_table;
#define __fmode (*(user_data->fmode_ptr))
diff --git a/winsup/cygwin/fhandler_console.cc
b/winsup/cygwin/fhandler_console.cc
index 709b8255d..86c39db25 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -499,9 +499,6 @@ fhandler_console::process_input_message (void)
termios *ti = &(get_ttyp ()->ti);
- /* Per MSDN, max size of buffer required is below 64K. */
-#define INREC_SIZE(65536 / sizeof (INPUT_RECORD))
-
fhandler_console::input_states stat = input_processing;
DWORD total_read, i;
INPUT_RECORD input_rec[INREC_SIZE];
@@ -1165,9 +1162,6 @@ fhandler_console::ioctl (unsigned int cmd, void *arg)
return -1;
case FIONREAD:
{
- /* Per MSDN, max size of buffer required is below 64K. */
-#define INREC_SIZE(65536 / sizeof (INPUT_RECORD))
-
DWORD n;
int ret = 0;
INPUT_RECORD inp[INREC_SIZE];
diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
index ed8c98d1c..e7014422b 100644
--- a/winsup/cygwin/select.cc
+++ b/winsup/cygwin/select.cc
@@ -1209,7 +1209,6 @@ peek_pty_slave (select_record *s, bool from_select)
{
if (ptys->is_line_input ())
{
-#define INREC_SIZE (65536 / sizeof (INPUT_RECORD))
INPUT_RECORD inp[INREC_SIZE];
DWORD n;
PeekConsoleInput (ptys->get_handle (), inp, INREC_SIZE, );
--
2.21.0
Re: [PATCH] Cygwin: console: Revive Win7 compatibility.
On Wed, 18 Sep 2019 18:21:49 +0200 Achim Gratz wrote: > Takashi Yano writes: > > - The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7 > > compatibility. This patch fixes the issue. > > --- > > winsup/cygwin/fhandler_console.cc | 10 +- > > winsup/cygwin/select.cc | 2 +- > > 2 files changed, 6 insertions(+), 6 deletions(-) > > It seems like an attractor for future bugs to define the same constant > in two different places. Would there be a header that could provide the > definition instead? I agree with you. I will post revised one as v2. -- Takashi Yano
[PATCH v2 0/1] Cygwin: console: Revive Win7 compatibility.
- The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7 compatibility. This patch fixes the issue. v2: Move definition of INREC_SIZE into fhandler.h from fhandler_console.cc and select.cc. Takashi Yano (1): Cygwin: console: Revive Win7 compatibility. winsup/cygwin/fhandler.h | 6 ++ winsup/cygwin/fhandler_console.cc | 6 -- winsup/cygwin/select.cc | 1 - 3 files changed, 6 insertions(+), 7 deletions(-) -- 2.21.0
Re: [PATCH] Cygwin: console: Revive Win7 compatibility.
Takashi Yano writes: > - The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7 > compatibility. This patch fixes the issue. > --- > winsup/cygwin/fhandler_console.cc | 10 +- > winsup/cygwin/select.cc | 2 +- > 2 files changed, 6 insertions(+), 6 deletions(-) It seems like an attractor for future bugs to define the same constant in two different places. Would there be a header that could provide the definition instead? Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Wavetables for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldUserWavetables
[PATCH 4/5] Cygwin: pty: Add charset conversion for console apps in legacy PTY.
---
winsup/cygwin/fhandler_tty.cc | 7 +++
1 file changed, 7 insertions(+)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index f723ec7cf..2a92e44cf 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -3054,6 +3054,12 @@ fhandler_pty_master::pty_master_fwd_thread ()
mb_str_free (buf);
continue;
}
+ size_t nlen;
+ char *buf = convert_mb_str
+ (get_ttyp ()->term_code_page, , GetConsoleOutputCP (), ptr, wlen);
+
+ ptr = buf;
+ wlen = rlen = nlen;
acquire_output_mutex (INFINITE);
while (rlen>0)
{
@@ -3066,6 +3072,7 @@ fhandler_pty_master::pty_master_fwd_thread ()
wlen = (rlen -= wlen);
}
release_output_mutex ();
+ mb_str_free (buf);
}
return 0;
}
--
2.21.0
[PATCH 3/5] Cygwin: pty: Unify the charset conversion codes into a function.
---
winsup/cygwin/fhandler_tty.cc | 130 +-
1 file changed, 49 insertions(+), 81 deletions(-)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 843807aab..f723ec7cf 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -370,7 +370,43 @@ CreateProcessW_Hooked
void set_ishybrid_and_switch_to_pcon (HANDLE) {}
#endif /* USE_API_HOOK */
-bool
+static char *
+convert_mb_str (UINT cp_to, size_t *len_to,
+ UINT cp_from, const char *ptr_from, size_t len_from)
+{
+ char *buf;
+ size_t nlen;
+ if (cp_to != cp_from)
+{
+ size_t wlen =
+ MultiByteToWideChar (cp_from, 0, ptr_from, len_from, NULL, 0);
+ wchar_t *wbuf = (wchar_t *)
+ HeapAlloc (GetProcessHeap (), 0, wlen * sizeof (wchar_t));
+ wlen =
+ MultiByteToWideChar (cp_from, 0, ptr_from, len_from, wbuf, wlen);
+ nlen = WideCharToMultiByte (cp_to, 0, wbuf, wlen, NULL, 0, NULL, NULL);
+ buf = (char *) HeapAlloc (GetProcessHeap (), 0, nlen);
+ nlen = WideCharToMultiByte (cp_to, 0, wbuf, wlen, buf, nlen, NULL, NULL);
+ HeapFree (GetProcessHeap (), 0, wbuf);
+}
+ else
+{
+ /* Just copy */
+ buf = (char *) HeapAlloc (GetProcessHeap (), 0, len_from);
+ memcpy (buf, ptr_from, len_from);
+ nlen = len_from;
+}
+ *len_to = nlen;
+ return buf;
+}
+
+static void
+mb_str_free (char *ptr)
+{
+ HeapFree (GetProcessHeap (), 0, ptr);
+}
+
+static bool
bytes_available (DWORD& n, HANDLE h)
{
DWORD navail, nleft;
@@ -1270,34 +1306,11 @@ fhandler_pty_slave::write (const void *ptr, size_t len)
reset_switch_to_pcon ();
- char *buf;
- ssize_t nlen;
- UINT targetCodePage = get_ttyp ()->switch_to_pcon_out ?
+ UINT target_code_page = get_ttyp ()->switch_to_pcon_out ?
GetConsoleOutputCP () : get_ttyp ()->term_code_page;
- if (targetCodePage != get_ttyp ()->term_code_page)
-{
- size_t wlen =
- MultiByteToWideChar (get_ttyp ()->term_code_page, 0,
-(char *)ptr, len, NULL, 0);
- wchar_t *wbuf = (wchar_t *)
- HeapAlloc (GetProcessHeap (), 0, wlen * sizeof (wchar_t));
- wlen =
- MultiByteToWideChar (get_ttyp ()->term_code_page, 0,
-(char *)ptr, len, wbuf, wlen);
- nlen = WideCharToMultiByte (targetCodePage, 0,
- wbuf, wlen, NULL, 0, NULL, NULL);
- buf = (char *) HeapAlloc (GetProcessHeap (), 0, nlen);
- nlen = WideCharToMultiByte (targetCodePage, 0,
- wbuf, wlen, buf, nlen, NULL, NULL);
- HeapFree (GetProcessHeap (), 0, wbuf);
-}
- else
-{
- /* Just copy */
- buf = (char *) HeapAlloc (GetProcessHeap (), 0, len);
- memcpy (buf, (char *)ptr, len);
- nlen = len;
-}
+ ssize_t nlen;
+ char *buf = convert_mb_str (target_code_page, (size_t *) ,
+get_ttyp ()->term_code_page, (const char *) ptr, len);
/* If not attached to this pseudo console, try to attach temporarily. */
pid_restore = 0;
@@ -1334,7 +1347,7 @@ fhandler_pty_slave::write (const void *ptr, size_t len)
towrite = -1;
}
release_output_mutex ();
- HeapFree (GetProcessHeap (), 0, buf);
+ mb_str_free (buf);
flags = ENABLE_VIRTUAL_TERMINAL_PROCESSING;
if (get_ttyp ()->switch_to_pcon_out && !fallback)
SetConsoleMode (get_output_handle (), dwMode | flags);
@@ -2260,33 +2273,10 @@ fhandler_pty_master::write (const void *ptr, size_t len)
if current application is native console application. */
if (to_be_read_from_pcon ())
{
- char *buf;
size_t nlen;
+ char *buf = convert_mb_str
+ (CP_UTF8, , get_ttyp ()->term_code_page, (const char *) ptr, len);
- if (get_ttyp ()->term_code_page != CP_UTF8)
- {
- size_t wlen =
- MultiByteToWideChar (get_ttyp ()->term_code_page, 0,
-(char *)ptr, len, NULL, 0);
- wchar_t *wbuf = (wchar_t *)
- HeapAlloc (GetProcessHeap (), 0, wlen * sizeof (wchar_t));
- wlen =
- MultiByteToWideChar (get_ttyp ()->term_code_page, 0,
-(char *)ptr, len, wbuf, wlen);
- nlen = WideCharToMultiByte (CP_UTF8, 0,
- wbuf, wlen, NULL, 0, NULL, NULL);
- buf = (char *) HeapAlloc (GetProcessHeap (), 0, nlen);
- nlen = WideCharToMultiByte (CP_UTF8, 0,
- wbuf, wlen, buf, nlen, NULL, NULL);
- HeapFree (GetProcessHeap (), 0, wbuf);
- }
- else
- {
- /* Just copy */
- buf = (char *) HeapAlloc (GetProcessHeap (), 0, len);
- memcpy (buf, (char *)ptr, len);
- nlen = len;
- }
DWORD wLen;
WriteFile (to_slave, buf, nlen, , NULL);
@@ -2302,7 +2292,7 @@ fhandler_pty_master::write (const void *ptr, size_t len)
else
SetEvent
[PATCH] Cygwin: console: Make console input work in GDB and strace.
- After commit 2232498c712acc97a38fdc297cbe53ba74d0ec2c, console input cause error in GDB or strace. This patch fixes this issue. --- winsup/cygwin/fhandler_termios.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/fhandler_termios.cc b/winsup/cygwin/fhandler_termios.cc index 5b0ba5603..282f0fbf4 100644 --- a/winsup/cygwin/fhandler_termios.cc +++ b/winsup/cygwin/fhandler_termios.cc @@ -202,7 +202,8 @@ fhandler_termios::bg_check (int sig, bool dontsignal) */ if (!myself->pgid || !tc () || tc ()->getpgid () == myself->pgid || myself->ctty != tc ()->ntty || - ((sig == SIGTTOU) && !(tc ()->ti.c_lflag & TOSTOP))) + ((sig == SIGTTOU) && !(tc ()->ti.c_lflag & TOSTOP)) || + being_debugged ()) return bg_ok; /* sig -SIGTTOU is used to indicate a change to terminal settings, where -- 2.21.0
[PATCH 0/5] Some fixes for PTY with pseudo console support (4)
Takashi Yano (5): Cygwin: pty: Avoid potential segfault in PTY code when ppid = 1. Cygwin: pty: Make GDB work again on pty. Cygwin: pty: Unify the charset conversion codes into a function. Cygwin: pty: Add charset conversion for console apps in legacy PTY. Cygwin: pty: Add missing guard when PTY is in the legacy mode. winsup/cygwin/fhandler_tty.cc | 188 +++--- 1 file changed, 104 insertions(+), 84 deletions(-) -- 2.21.0
[PATCH 1/5] Cygwin: pty: Avoid potential segfault in PTY code when ppid = 1.
---
winsup/cygwin/fhandler_tty.cc | 11 +--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 659e7b595..2a1c34f7d 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -137,9 +137,16 @@ force_attach_to_pcon (HANDLE h)
/* If the process is running on a console,
the parent process should be attached
to the same console. */
- pinfo p (myself->ppid);
+ DWORD attach_wpid;
+ if (myself->ppid == 1)
+ attach_wpid = ATTACH_PARENT_PROCESS;
+ else
+ {
+ pinfo p (myself->ppid);
+ attach_wpid = p->dwProcessId;
+ }
FreeConsole ();
- if (AttachConsole (p->dwProcessId))
+ if (AttachConsole (attach_wpid))
{
pcon_attached_to = -1;
attach_done = true;
--
2.21.0
[PATCH 5/5] Cygwin: pty: Add missing guard when PTY is in the legacy mode.
---
winsup/cygwin/fhandler_tty.cc | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 2a92e44cf..1095c82eb 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -87,7 +87,8 @@ set_switch_to_pcon (void)
{
fhandler_base *fh = cfd;
fhandler_pty_slave *ptys = (fhandler_pty_slave *) fh;
- ptys->set_switch_to_pcon (fd);
+ if (ptys->getPseudoConsole ())
+ ptys->set_switch_to_pcon (fd);
}
}
@@ -105,6 +106,8 @@ force_attach_to_pcon (HANDLE h)
{
fhandler_base *fh = cfd;
fhandler_pty_slave *ptys = (fhandler_pty_slave *) fh;
+ if (!ptys->getPseudoConsole ())
+ continue;
if (n != 0
|| h == ptys->get_handle ()
|| h == ptys->get_output_handle ())
--
2.21.0
[PATCH 2/5] Cygwin: pty: Make GDB work again on pty.
---
winsup/cygwin/fhandler_tty.cc | 35 +++
1 file changed, 35 insertions(+)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 2a1c34f7d..843807aab 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -197,6 +197,9 @@ DEF_HOOK (ReadConsoleInputA);
DEF_HOOK (ReadConsoleInputW);
DEF_HOOK (PeekConsoleInputA);
DEF_HOOK (PeekConsoleInputW);
+/* CreateProcess() is hooked for GDB etc. */
+DEF_HOOK (CreateProcessA);
+DEF_HOOK (CreateProcessW);
static BOOL WINAPI
WriteFile_Hooked
@@ -331,6 +334,35 @@ PeekConsoleInputW_Hooked
set_ishybrid_and_switch_to_pcon (h);
return PeekConsoleInputW_Orig (h, r, l, n);
}
+/* CreateProcess() is hooked for GDB etc. */
+static BOOL WINAPI
+CreateProcessA_Hooked
+ (LPCSTR n, LPSTR c, LPSECURITY_ATTRIBUTES pa, LPSECURITY_ATTRIBUTES ta,
+ BOOL inh, DWORD f, LPVOID e, LPCSTR d,
+ LPSTARTUPINFOA si, LPPROCESS_INFORMATION pi)
+{
+ HANDLE h;
+ if (si->dwFlags & STARTF_USESTDHANDLES)
+h = si->hStdOutput;
+ else
+h = GetStdHandle (STD_OUTPUT_HANDLE);
+ set_ishybrid_and_switch_to_pcon (h);
+ return CreateProcessA_Orig (n, c, pa, ta, inh, f, e, d, si, pi);
+}
+static BOOL WINAPI
+CreateProcessW_Hooked
+ (LPCWSTR n, LPWSTR c, LPSECURITY_ATTRIBUTES pa, LPSECURITY_ATTRIBUTES ta,
+ BOOL inh, DWORD f, LPVOID e, LPCWSTR d,
+ LPSTARTUPINFOW si, LPPROCESS_INFORMATION pi)
+{
+ HANDLE h;
+ if (si->dwFlags & STARTF_USESTDHANDLES)
+h = si->hStdOutput;
+ else
+h = GetStdHandle (STD_OUTPUT_HANDLE);
+ set_ishybrid_and_switch_to_pcon (h);
+ return CreateProcessW_Orig (n, c, pa, ta, inh, f, e, d, si, pi);
+}
#else /* USE_API_HOOK */
#define WriteFile_Orig 0
#define ReadFile_Orig 0
@@ -2778,6 +2810,9 @@ fhandler_pty_slave::fixup_after_exec ()
DO_HOOK (NULL, ReadConsoleInputW);
DO_HOOK (NULL, PeekConsoleInputA);
DO_HOOK (NULL, PeekConsoleInputW);
+ /* CreateProcess() is hooked for GDB etc. */
+ DO_HOOK (NULL, CreateProcessA);
+ DO_HOOK (NULL, CreateProcessW);
}
#endif /* USE_API_HOOK */
}
--
2.21.0
[PATCH] Cygwin: console: Revive Win7 compatibility.
- The commit fca4cda7a420d7b15ac217d008527e029d05758e broke Win7
compatibility. This patch fixes the issue.
---
winsup/cygwin/fhandler_console.cc | 10 +-
winsup/cygwin/select.cc | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/winsup/cygwin/fhandler_console.cc
b/winsup/cygwin/fhandler_console.cc
index 709b8255d..75143f27a 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -499,8 +499,11 @@ fhandler_console::process_input_message (void)
termios *ti = &(get_ttyp ()->ti);
- /* Per MSDN, max size of buffer required is below 64K. */
-#define INREC_SIZE(65536 / sizeof (INPUT_RECORD))
+ /* Per MSDN, max size of buffer required is below 64K. */
+ /* (65536 / sizeof (INPUT_RECORD)) is 3276, however,
+ ERROR_NOT_ENOUGH_MEMORY occurs in win7 if this value
+ is used. */
+#define INREC_SIZE 2048
fhandler_console::input_states stat = input_processing;
DWORD total_read, i;
@@ -1165,9 +1168,6 @@ fhandler_console::ioctl (unsigned int cmd, void *arg)
return -1;
case FIONREAD:
{
- /* Per MSDN, max size of buffer required is below 64K. */
-#define INREC_SIZE(65536 / sizeof (INPUT_RECORD))
-
DWORD n;
int ret = 0;
INPUT_RECORD inp[INREC_SIZE];
diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc
index ed8c98d1c..8fdce06a4 100644
--- a/winsup/cygwin/select.cc
+++ b/winsup/cygwin/select.cc
@@ -1209,7 +1209,7 @@ peek_pty_slave (select_record *s, bool from_select)
{
if (ptys->is_line_input ())
{
-#define INREC_SIZE (65536 / sizeof (INPUT_RECORD))
+#define INREC_SIZE 2048
INPUT_RECORD inp[INREC_SIZE];
DWORD n;
PeekConsoleInput (ptys->get_handle (), inp, INREC_SIZE, );
--
2.21.0
