From: Al Viro Date: Thu, 4 Nov 2010 11:13:59 +0000 (+0000) Subject: MIPS: Don't stomp on caller's ->regs[2] in copy_thread() X-Git-Tag: v2.6.37-rc7~25^2~26 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a989ff898f9740651d00388c33bdf4f2a7914920;p=profile%2Fcommon%2Fkernel-common.git MIPS: Don't stomp on caller's ->regs[2] in copy_thread() We never needed that (->regs[2] is overwritten on return from syscall paths with return value of syscall, so storing it there early made no sense) and with new restart logics since d27240bf7e61d2656de18e158ec910a902030847 it has become really bad - we lose the original syscall number before the place where we decide that we might need a syscall restart. Note that for child we do need the assignment to regs[2] - it won't go through the normal return from syscall path. [Ralf: Issue found and reported by Lluís; initial investigations by me; bug finally found and patch by Al; testing by me and Lluís.] Signed-off-by: Al Viro Tested-by: Lluís Batlle i Rossell Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 9996094..ae167df 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -142,7 +142,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, childregs->regs[7] = 0; /* Clear error flag */ childregs->regs[2] = 0; /* Child gets zero as return value */ - regs->regs[2] = p->pid; if (childregs->cp0_status & ST0_CU0) { childregs->regs[28] = (unsigned long) ti;