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Commit 33573c0e authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Fix occasional flush_cache_4096() stack corruption. 



IRQs disabling in flush_cache_4096 for cache purge. Under certain
workloads we would get an IRQ in the middle of a purge operation,
and the cachelines would remain in an inconsistent state, leading
to occasional stack corruption.

Signed-off-by: default avatarTakeo Takahashi <takahashi.takeo@renesas.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent f3c25758

arch/sh/mm/cache-sh4.c

+9 −11
Original line number Diff line number Diff line
@@ -221,22 +221,20 @@ void flush_cache_sigtramp(unsigned long addr) 
static inline void flush_cache_4096(unsigned long start,

				    unsigned long phys)

{

	unsigned long flags, exec_offset = 0;



	/*

	 * All types of SH-4 require PC to be in P2 to operate on the I-cache.

	 * Some types of SH-4 require PC to be in P2 to operate on the D-cache.

	 */

	if ((cpu_data->flags & CPU_HAS_P2_FLUSH_BUG) ||

	    (start < CACHE_OC_ADDRESS_ARRAY)) {

		unsigned long flags;

	    (start < CACHE_OC_ADDRESS_ARRAY))

	    	exec_offset = 0x20000000;



	local_irq_save(flags);

	__flush_cache_4096(start | SH_CACHE_ASSOC,

				   P1SEGADDR(phys), 0x20000000);

			   P1SEGADDR(phys), exec_offset);

	local_irq_restore(flags);

	} else {

		__flush_cache_4096(start | SH_CACHE_ASSOC,

				   P1SEGADDR(phys), 0);

	}

}



/*