Cygwin: pipe: Fix hang due to inadvertent 0-length raw_write() and some signal fixes #91
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/open pr The workflow run was started |
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I just merged msys2/msys2-runtime#271, so let's deploy the fix to Git for Windows' Pacman repository, too. |
It is possible for `NtQueryInformationFile()` to report a 0-length `InboundQuota` when obtaining `FilePipeLocalInformation`. This seems to be the case e.g. when a pipe was created on the other side and its quota information is not available on the client side. This can lead to a situation where the `avail` variable is set to 0, and since that is used to cap the number of bytes to send, a 0-length write. Which hangs forever. This was observed in the MSYS2 project when building GIMP, and reduced to a simple test case where a MINGW `ninja.exe` tries to call an MSYS `bison.exe` and the error message (saying that `bison` wants to have some input) is not even shown. Since the minimal pipe buffer size is 4k, let's ensure that it is at least that, even when `InboundQuota` reports 0. This fixes msys2/msys2-runtime#270 Fixes: cbfaeba (Cygwin: pipe: Fix incorrect write length in raw_write()) Helped-by: Corinna Vinschen <[email protected]> Signed-off-by: Johannes Schindelin <[email protected]>
x86_64 ABI requires the direction flag in CPU flags register cleared. https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions However, currently that flag is not maintained in signal handler. Therefore, if the signal handler is called when that flag is set, it destroys the data and may crash if rep instruction is used in the signal handler. With this patch, the direction flag is cleared in sigdelayed() by adding cld instruction. Backported-from: d71aeccff4 (Cygwin: signal: Clear direction flag in sigdeleyed, 2025-03-24) Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257704.html Fixes: 1fd5e00 ("import winsup-2000-02-17 snapshot") Reported-by: Christian Franke <[email protected]> Reviewed-by: Corinna Vischen <[email protected]> Signed-off-by: Takashi Yano <[email protected]> (cherry picked from commit 9f4cec47df66a913256912c358afe5e597dec25c) Signed-off-by: Johannes Schindelin <[email protected]>
dscho
changed the title
After the commit 0210c77, the context passed to signal handler cannot be accessed from the signal handler that uses alternate stack. This is because the context locally copied is on the stack that is different area from the signal handler uses. With this patch, copy the context to alternate signal stack area to avoid this situation. Backported-from: 7f67575711 (Cygwin: signal: Copy context to alternate stack in the SA_ONSTACK case, 2025-03-25) Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257714.html Fixes: 0210c77 ("Cygwin: signal: Use context locally copied in call_signal_handler()") Reported-by: Bruno Haible <[email protected]> Reviewed-by: Corinna Vischen <[email protected]> Signed-off-by: Takashi Yano <[email protected]> (cherry picked from commit 0d0e76b99025704d8ee44a44b19a23af9aafe297) Signed-off-by: Johannes Schindelin <[email protected]>
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/open pr The workflow run was started |
This was referenced Mar 31, 2025
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This is a companion of msys2/msys2-runtime#271 and of https://inbox.sourceware.org/cygwin-patches/40a66dcf272eff407794bb94616d5b8ba833fafa.1743076896.git.johannes.schindelin@gmx.de/.
It also backports d71aeccff4d219b1cc7a6b0d17dcea7e5bb1b2e9 and 7f67575711f91ee0b738f836e2ed93c2e41b5248.
This closes git-for-windows/git#5521 and git-for-windows/git#5522.