Merge branch 'sparc64-non-resumable-user-error-recovery'

Liam R. Howlett says:

====================
sparc64: Recover from userspace non-resumable PIO & MEM errors

A non-resumable error from userspace is able to cause a kernel panic or trap
loop due to the setup and handling of the queued traps once in the kernel.
This patch series addresses both of these issues.

The queues are fixed by simply zeroing the memory before use.

PIO errors from userspace will result in a SIGBUS being sent to the user
process.

The MEM errors form userspace will result in a SIGKILL and also cause the
offending pages to be claimed so they are no longer used in future tasks.
SIGKILL is used to ensure that the process does not try to coredump and result
in an attempt to read the memory again from within kernel space.  Although
there is a HV call to scrub the memory (mem_scrub), there is no easy way to
guarantee that the real memory address(es) are not used by other tasks.
Clearing the error with mem_scrub would zero the memory and cause the other
processes to proceed with bad data.

The handling of other non-resumable errors remain unchanged and will cause a
panic.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

path: root/include/net/hwbm.h

#ifndef _HWBM_H
#define _HWBM_H

struct hwbm_pool {
	/* Capacity of the pool */
	int size;
	/* Size of the buffers managed */
	int frag_size;
	/* Number of buffers currently used by this pool */
	int buf_num;
	/* constructor called during alocation */
	int (*construct)(struct hwbm_pool *bm_pool, void *buf);
	/* protect acces to the buffer counter*/
	spinlock_t lock;
	/* private data */
	void *priv;
};
#ifdef CONFIG_HWBM
void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf);
int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp);
int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp);
#else
void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {}
int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) { return 0; }
int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num, gfp_t gfp)
{ return 0; }
#endif /* CONFIG_HWBM */
#endif /* _HWBM_H */