[PATCH] Signal hadnling fix for 2.4

Stephen Rothwell sfr at canb.auug.org.au
Mon Feb 27 16:03:37 EST 2006


Hi Marcelo,

While investigating a bug report about a 64bit application that crashed in
malloc, Paul Mackerras noticed that sys_rt_sigreturn's return value was
"int".  It needs to be "long" or else the return value of a syscall that
is interrupted by a signal will be truncated to 32 bits and then sign
extended.  This causes .e.g mmap's return value to be corrupted if it is
returning an address above 2^31 (which is what caused a SEGV in malloc).
This problem obviously only affects 64 bit processes.

Signed-off-by: Stephen Rothwell <sfr at canb.auug.org.au>

---

Please apply for 2.4.33, this patch is against 2.4.33-pre2.

-- 
Cheers,
Stephen Rothwell                    sfr at canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

diff -ruN linux/arch/ppc64/kernel/signal.c linux-sfr/arch/ppc64/kernel/signal.c
--- linux/arch/ppc64/kernel/signal.c	2006-02-24 17:37:08.000000000 +1100
+++ linux-sfr/arch/ppc64/kernel/signal.c	2006-02-27 11:05:07.000000000 +1100
@@ -332,7 +332,7 @@
 }
 
 
-asmlinkage int
+asmlinkage long
 sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 		 unsigned long r6, unsigned long r7, unsigned long r8,
 		 struct pt_regs *regs)



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