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| author | Corinna Vinschen <corinna@vinschen.de> | 2024-10-31 11:52:26 +0100 |
|---|---|---|
| committer | Corinna Vinschen <corinna@vinschen.de> | 2024-10-31 13:15:29 +0100 |
| commit | 1f05c040599afe63af8c7ecfe71bc461f393600d (patch) | |
| tree | 71c81733dd631ddadd8446e265fd812a61cbc513 /winsup/cygwin | |
| parent | 04f386e9af997d0929e90556cce712346bef0d68 (diff) | |
| download | newlib-1f05c040599afe63af8c7ecfe71bc461f393600d.zip newlib-1f05c040599afe63af8c7ecfe71bc461f393600d.tar.gz newlib-1f05c040599afe63af8c7ecfe71bc461f393600d.tar.bz2 | |
Cygwin: pipe: fix shift value
The expression computing the next-less-power of 2 for the next write
when the pipe buffer is getting filled up allows negative shift values.
This works on Intel CPUs because the shift expression only evaluates the
5 LSBs, but it's undefined behaviour per the C standard. Use the
correct expression to get a positive shift value.
Fixes: 170e6badb621 ("Cygwin: pipe: improve writing when pipe buffer is almost full")
Reported-by: Takashi Yano <takashi.yano@nifty.ne.jp>
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diffstat (limited to 'winsup/cygwin')
| -rw-r--r-- | winsup/cygwin/fhandler/pipe.cc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/winsup/cygwin/fhandler/pipe.cc b/winsup/cygwin/fhandler/pipe.cc index c686df6..7370bd8 100644 --- a/winsup/cygwin/fhandler/pipe.cc +++ b/winsup/cygwin/fhandler/pipe.cc @@ -575,7 +575,7 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) else if (avail >= PIPE_BUF) len1 = avail & ~(PIPE_BUF - 1); else - len1 = 1 << (31 - __builtin_clzl (avail)); + len1 = 1 << (63 - __builtin_clzl (avail)); short_write_once = true; } if (isclosed ()) /* A signal handler might have closed the fd. */ |