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#include <stdio.h>
#include <signal.h>

#include "sig.h"

void register_signal(int signal, void (*handler)(int))
{
	sigset_t block_mask;
	struct sigaction saction;

	sigfillset(&block_mask);

	saction.sa_handler = handler;
	saction.sa_mask = block_mask;
	saction.sa_flags = SA_RESTART;

	sigaction(signal, &saction, NULL);
}

void register_signal_f(int signal, void (*handler)(int), int flags)
{
	sigset_t block_mask;
	struct sigaction saction;

	sigfillset(&block_mask);

	saction.sa_handler = handler;
	saction.sa_mask = block_mask;
	saction.sa_flags = flags;

	sigaction(signal, &saction, NULL);
}
a221871ffc04bb752216b823001'>0625c2dd6ae32a221871ffc04bb752216b823001 (patch) treeade4401e23b075b947ca9d5453d2b538f37203a3 /fs/nfs/nfs4namespace.c parentcd3fadece2b97462583500371a3eb9b091c49603 (diff)
NFS: Fix possible endless state recovery wait
In nfs4_wait_clnt_recover(), hold a reference to the clp being waited on. The state manager can reduce clp->cl_count to 1, in which case the nfs_put_client() in nfs4_run_state_manager() can free *clp before wait_on_bit() returns and allows nfs4_wait_clnt_recover() to run again. The behavior at that point is non-deterministic. If the waited-on bit still happens to be zero, wait_on_bit() will wake the waiter as expected. If the bit is set again (say, if the memory was poisoned when freed) wait_on_bit() can leave the waiter asleep. This is a narrow fix which ensures the safety of accessing *clp in nfs4_wait_clnt_recover(), but does not address the continued use of a possibly freed *clp after nfs4_wait_clnt_recover() returns (see nfs_end_delegation_return(), for example). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4namespace.c')