diff options
| -rw-r--r-- | winsup/cygwin/exceptions.cc | 8 | ||||
| -rw-r--r-- | winsup/cygwin/release/3.6.1 | 5 |
2 files changed, 13 insertions, 0 deletions
diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc index 2e25aa2..a3aae2c 100644 --- a/winsup/cygwin/exceptions.cc +++ b/winsup/cygwin/exceptions.cc @@ -1791,6 +1791,13 @@ _cygtls::call_signal_handler () to 16 byte. */ uintptr_t new_sp = ((uintptr_t) _my_tls.altstack.ss_sp + _my_tls.altstack.ss_size) & ~0xf; + /* Copy context1 to the alternate signal stack area, because the + context1 allocated in the normal stack area is not accessible + from the signal handler that uses alternate signal stack. */ + thiscontext = (ucontext_t *) ((new_sp - sizeof (ucontext_t)) & ~0xf); + memcpy (thiscontext, &context1, sizeof (ucontext_t)); + new_sp = (uintptr_t) thiscontext; + /* In assembler: Save regs on new stack, move to alternate stack, call thisfunc, revert stack regs. */ #ifdef __x86_64__ @@ -1834,6 +1841,7 @@ _cygtls::call_signal_handler () #else #error unimplemented for this target #endif + memcpy (&context1, thiscontext, sizeof (ucontext_t)); } else /* No alternate signal stack requested or available, just call diff --git a/winsup/cygwin/release/3.6.1 b/winsup/cygwin/release/3.6.1 index 40ef297..95c2c05 100644 --- a/winsup/cygwin/release/3.6.1 +++ b/winsup/cygwin/release/3.6.1 @@ -10,3 +10,8 @@ Fixes: - getlocalename_l: Fix a crash and handle LC_ALL according to final POSIX-1.2024 docs. Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257715.html + +- Copy context to alternate signal stack area in call_signal_handler() + in the SA_ONSTACK case, because locally-copied context on the normal + stack area is not accessible from the signal handler. + Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257714.html |