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Commit 442d3924 authored by cpw@sgi.com's avatar cpw@sgi.com Committed by Ingo Molnar
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x86, UV: Remove cpumask_t from the stack 



Remove the large stack-resident cpumask_t from
reset_with_ipi()'s stack by allocating one per uvhub.

Due to the limited size of the stack the potentially huge cpumask_t may
cause stack overrun.  We haven't seen it happen yet, but we need to make it
a practice not to push such structures onto the stack.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Reviewed-by: default avatarPekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20110621122242.832589130@sgi.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a456eaab

arch/x86/include/asm/uv/uv_bau.h

+1 −0
Original line number Diff line number Diff line
@@ -488,6 +488,7 @@ struct bau_control { 
	struct bau_control	*uvhub_master;

	struct bau_control	*socket_master;

	struct ptc_stats	*statp;

	cpumask_t		*cpumask;

	unsigned long		timeout_interval;

	unsigned long		set_bau_on_time;

	atomic_t		active_descriptor_count;

arch/x86/platform/uv/tlb_uv.c

+15 −4
Original line number Diff line number Diff line
@@ -375,13 +375,13 @@ static void reset_with_ipi(struct pnmask *distribution, struct bau_control *bcp) 
	int pnode;

	int apnode;

	int maskbits;

	cpumask_t mask;

	int sender = bcp->cpu;

	cpumask_t *mask = bcp->uvhub_master->cpumask;

	struct bau_control *smaster = bcp->socket_master;

	struct reset_args reset_args;



	reset_args.sender = sender;

	cpus_clear(mask);

	cpus_clear(*mask);

	/* find a single cpu for each uvhub in this distribution mask */

	maskbits = sizeof(struct pnmask) * BITSPERBYTE;

	/* each bit is a pnode relative to the partition base pnode */
@@ -391,11 +391,11 @@ static void reset_with_ipi(struct pnmask *distribution, struct bau_control *bcp) 
			continue;

		apnode = pnode + bcp->partition_base_pnode;

		cpu = pnode_to_first_cpu(apnode, smaster);

		cpu_set(cpu, mask);

		cpu_set(cpu, *mask);

	}



	/* IPI all cpus; preemption is already disabled */

	smp_call_function_many(&mask, do_reset, (void *)&reset_args, 1);

	smp_call_function_many(mask, do_reset, (void *)&reset_args, 1);

	return;

}
@@ -1695,6 +1695,16 @@ static void make_per_cpu_thp(struct bau_control *smaster) 
	}

}



/*

 * Each uvhub is to get a local cpumask.

 */

static void make_per_hub_cpumask(struct bau_control *hmaster)

{

	int sz = sizeof(cpumask_t);



	hmaster->cpumask = kzalloc_node(sz, GFP_KERNEL, hmaster->osnode);

}



/*

 * Initialize all the per_cpu information for the cpu's on a given socket,

 * given what has been gathered into the socket_desc struct.
@@ -1765,6 +1775,7 @@ static int __init summarize_uvhub_sockets(int nuvhubs, 
			socket++;

			socket_mask = (socket_mask >> 1);

		}

		make_per_hub_cpumask(hmaster);

	}

	return 0;

}