Commit d99a043a authored Sep 01, 2016 by James Hogan Committed by Ralf Baechle Oct 04, 2016

MIPS: uprobes: Flush icache via kernel address



Update arch_uprobe_copy_ixol() to use the kmap_atomic() based kernel
address to flush the icache with flush_icache_range(), rather than the
user mapping. We have the kernel mapping available anyway and this
avoids having to switch to using the new __flush_icache_user_range() for
the sake of Enhanced Virtual Addressing (EVA) where flush_icache_range()
will become ineffective on user addresses.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14154/
Patchwork: https://patchwork.linux-mips.org/patch/14308/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent 8e3a9f4c

arch/mips/kernel/uprobes.c

+6 −11

Original line number	Diff line number	Diff line
		@@ -282,19 +282,14 @@ int __weak set_swbp(struct arch_uprobe auprobe, struct mm_struct mm,
		void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
		void *src, unsigned long len)
		{
		void *kaddr;
		unsigned long kaddr, kstart;

		/* Initialize the slot */
		kaddr = kmap_atomic(page);
		memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
		kunmap_atomic(kaddr);

		/*
		* The MIPS version of flush_icache_range will operate safely on
		* user space addresses and more importantly, it doesn't require a
		* VMA argument.
		*/
		flush_icache_range(vaddr, vaddr + len);
		kaddr = (unsigned long)kmap_atomic(page);
		kstart = kaddr + (vaddr & ~PAGE_MASK);
		memcpy((void *)kstart, src, len);
		flush_icache_range(kstart, kstart + len);
		kunmap_atomic((void *)kaddr);
		}

		/**

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