0000480: On Mips, returning from a signal handler crashes the application

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Category

Severity

Reproducibility

Date Submitted

Last Update

0000480

[uClibc] Architecture Specific

major

always

10-11-05 08:48

01-05-06 19:07

Reporter

alain k

View Status

public

Assigned To

uClibc

Priority

normal

Resolution

fixed

Status

closed

Product Version

0.9.28

Summary

0000480: On Mips, returning from a signal handler crashes the application

Description

On Mips, program segfaults when returning from a signal handler.

The reason of this seems to be the following code snippet (from libc/sysdeps/linux/mips/sigaction.c):

    if (act) {
    kact.k_sa_handler = act->sa_handler;
    memcpy (&kact.sa_mask, &act->sa_mask, sizeof (kact.sa_mask));
    kact.sa_flags = act->sa_flags;

    kact.sa_flags = act->sa_flags | SA_RESTORER;
#ifdef HAVE_SA_RESTORER
    kact.sa_restorer = act->sa_restorer;
#endif
    }

This erroneously sets the SA_RESTORER unconditionnally, even if the application didn't request it. Result: on return from the signal handler, an uninitialized restorer is invoked, crashing the program.

Commenting out the offending line (kact.sa_flags = act->sa_flags | SA_RESTORER;) fixes the problem

Additional Information

Attached Files

Relationships

Notes
(0000860) vapier 01-05-06 19:07	mjn3 has updated that code so it no longer sets SA_RESTORER all the time

Issue History
Date Modified	Username	Field	Change
10-11-05 08:48	alain k	New Issue
10-11-05 08:48	alain k	Status	new => assigned
10-11-05 08:48	alain k	Assigned To	=> uClibc
01-05-06 19:07	vapier	Note Added: 0000860
01-05-06 19:07	vapier	Status	assigned => closed
01-05-06 19:07	vapier	Resolution	open => fixed
04-08-06 10:09	hsudek	Issue Monitored: hsudek
09-23-07 00:19	comio	Issue Monitored: comio