Skip to main content

Browse the archive

Revision 070e76cb3ffe43f6855492e77c96680c562598f0 authored by Leonid Yegoshin on 27 November 2014, 11:13:08 UTC, committed by Ralf Baechle on 27 November 2014, 16:21:56 UTC 
MIPS: tlbex: Fix potential HTW race on TLBL/M/S handlers
 
There is a potential race when probing the TLB in TLBL/M/S exception
handlers for a matching entry. Between the time we hit a TLBL/S/M
exception and the time we get to execute the TLBP instruction, the
HTW may have replaced the TLB entry we are interested in hence the TLB
probe may fail. However, in the existing handlers, we never checked the
status of the TLBP (ie check the result in the C0/Index register). We
fix this by adding such a check when the core implements the HTW. If
we couldn't find a matching entry, we return back and try again.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8599/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 parent b4da18b
Raw File
ghes.h 
#include <acpi/apei.h>
#include <acpi/hed.h>

/*
 * One struct ghes is created for each generic hardware error source.
 * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
 * handler.
 *
 * estatus: memory buffer for error status block, allocated during
 * HEST parsing.
 */
#define GHES_TO_CLEAR		0x0001
#define GHES_EXITING		0x0002

struct ghes {
	struct acpi_hest_generic *generic;
	struct acpi_hest_generic_status *estatus;
	u64 buffer_paddr;
	unsigned long flags;
	union {
		struct list_head list;
		struct timer_list timer;
		unsigned int irq;
	};
};

struct ghes_estatus_node {
	struct llist_node llnode;
	struct acpi_hest_generic *generic;
	struct ghes *ghes;
};

struct ghes_estatus_cache {
	u32 estatus_len;
	atomic_t count;
	struct acpi_hest_generic *generic;
	unsigned long long time_in;
	struct rcu_head rcu;
};

enum {
	GHES_SEV_NO = 0x0,
	GHES_SEV_CORRECTED = 0x1,
	GHES_SEV_RECOVERABLE = 0x2,
	GHES_SEV_PANIC = 0x3,
};

/* From drivers/edac/ghes_edac.c */

#ifdef CONFIG_EDAC_GHES
void ghes_edac_report_mem_error(struct ghes *ghes, int sev,
				struct cper_sec_mem_err *mem_err);

int ghes_edac_register(struct ghes *ghes, struct device *dev);

void ghes_edac_unregister(struct ghes *ghes);

#else
static inline void ghes_edac_report_mem_error(struct ghes *ghes, int sev,
				       struct cper_sec_mem_err *mem_err)
{
}

static inline int ghes_edac_register(struct ghes *ghes, struct device *dev)
{
	return 0;
}

static inline void ghes_edac_unregister(struct ghes *ghes)
{
}
#endif
back to top