Re: 2.6.x signal handler bug

[Andries Brouwer]

On Sat, Jun 26, 2004 at 09:05:34AM -0700, Davide Libenzi wrote:

> You're receiving a SIGSEGV while SIGSEGV is blocked (force_sig_info). The 
> force_sig_info call wants to send a signal that the task can't refuse 
> (kinda The GodFather offers ;). The kernel will noticed this and will 
> restore the handler to SIG_DFL.

Yes.

So checking whether this is POSIX conforming:

- Blocking a signal in its signal handler is explicitly allowed.
  (signal(3p))
- It is unspecified what longjmp() does with the signal mask.
  (longjmp(3p))
- The SIGSEGV that occurs during a stack overflow is of the GodFather kind.
  (getrlimit(3p))
- If SIGSEGV is generated while blocked, the result is undefined
  (sigprocmask(3p))

So, maybe the restoring to SIG_DFL was not required, but it doesnt seem
incorrect either. It may be a bit surprising.

Andries
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