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| author | Takashi Yano <takashi.yano@nifty.ne.jp> | 2025-03-24 09:26:34 +0900 |
|---|---|---|
| committer | Takashi Yano <takashi.yano@nifty.ne.jp> | 2025-03-24 21:28:13 +0900 |
| commit | bb2a8a8cb3ae8753dd275caffdef567f3c2da1b6 (patch) | |
| tree | e304ddc64effc6369269b4fec7d0811af5a5c964 | |
| parent | 764dbcafb3ec2aad04cfd02e4b3493bf7383a384 (diff) | |
| download | newlib-bb2a8a8cb3ae8753dd275caffdef567f3c2da1b6.zip newlib-bb2a8a8cb3ae8753dd275caffdef567f3c2da1b6.tar.gz newlib-bb2a8a8cb3ae8753dd275caffdef567f3c2da1b6.tar.bz2 | |
Cygwin: signal: Clear direction flag in sigdeleyed
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.
Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257704.html
Fixes: 1fd5e000ace5 ("import winsup-2000-02-17 snapshot")
Reported-by: Christian Franke <Christian.Franke@t-online.de>
Reviewed-by: Corinna Vischen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
| -rw-r--r-- | winsup/cygwin/release/3.6.1 | 3 | ||||
| -rwxr-xr-x | winsup/cygwin/scripts/gendef | 1 |
2 files changed, 4 insertions, 0 deletions
diff --git a/winsup/cygwin/release/3.6.1 b/winsup/cygwin/release/3.6.1 index 0b54b5f..0b05f45 100644 --- a/winsup/cygwin/release/3.6.1 +++ b/winsup/cygwin/release/3.6.1 @@ -3,3 +3,6 @@ Fixes: - Console mode is really restored to the previous mode. Addresses: https://github.com/msys2/msys2-runtime/issues/268 + +- Clear direction flag in sigdeleyed before calling signal handler. + Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257704.html diff --git a/winsup/cygwin/scripts/gendef b/winsup/cygwin/scripts/gendef index a2f0392..861a240 100755 --- a/winsup/cygwin/scripts/gendef +++ b/winsup/cygwin/scripts/gendef @@ -179,6 +179,7 @@ sigdelayed: movq %rsp,%rbp pushf .seh_pushreg %rax # fake, there's no .seh_pushreg for the flags + cld # x86_64 ABI requires direction flag cleared # stack is aligned or unaligned on entry! # make sure it is aligned from here on # We could be called from an interrupted thread which doesn't know |