From 6663484b4e2d98f5609dc1b90fe4c242dd8fe18a Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 29 Jun 2018 11:48:50 -0700 Subject: [PATCH] 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: Kees Cook Acked-by: Jan Glauber Cc: David Daney Cc: linux-edac 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: Borislav Petkov --- drivers/edac/thunderx_edac.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/edac/thunderx_edac.c b/drivers/edac/thunderx_edac.c index 4803c6468bab..c009d94f40c5 100644 --- a/drivers/edac/thunderx_edac.c +++ b/drivers/edac/thunderx_edac.c @@ -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; -- GitLab