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Commit 6663484b authored by Kees Cook's avatar Kees Cook Committed by Borislav Petkov
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EDAC, thunderx: Remove VLA usage 



In the quest to remove all stack VLA usage from the kernel[1], switch to
using a kmalloc-allocated buffer instead of stack space. This should be
fine since the existing routine is allocating memory too.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarJan Glauber <jglauber@cavium.com>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180629184850.GA37464@beast
Link: https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

 [1]
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent 6c974d4d

drivers/edac/thunderx_edac.c

+9 −5
Original line number Diff line number Diff line
@@ -408,26 +408,29 @@ static ssize_t thunderx_lmc_inject_ecc_write(struct file *file, 
					     size_t count, loff_t *ppos)

{

	struct thunderx_lmc *lmc = file->private_data;



	unsigned int cline_size = cache_line_size();



	u8 tmp[cline_size];

	u8 *tmp;

	void __iomem *addr;

	unsigned int offs, timeout = 100000;



	atomic_set(&lmc->ecc_int, 0);



	lmc->mem = alloc_pages_node(lmc->node, GFP_KERNEL, 0);



	if (!lmc->mem)

		return -ENOMEM;



	tmp = kmalloc(cline_size, GFP_KERNEL);

	if (!tmp) {

		__free_pages(lmc->mem, 0);

		return -ENOMEM;

	}



	addr = page_address(lmc->mem);



	while (!atomic_read(&lmc->ecc_int) && timeout--) {

		stop_machine(inject_ecc_fn, lmc, NULL);



		for (offs = 0; offs < PAGE_SIZE; offs += sizeof(tmp)) {

		for (offs = 0; offs < PAGE_SIZE; offs += cline_size) {

			/*

			 * Do a load from the previously rigged location

			 * This should generate an error interrupt.
@@ -437,6 +440,7 @@ static ssize_t thunderx_lmc_inject_ecc_write(struct file *file, 
		}

	}



	kfree(tmp);

	__free_pages(lmc->mem, 0);



	return count;