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authorJakub Kicinski <kuba@kernel.org>2022-11-29 13:04:52 -0800
committerJakub Kicinski <kuba@kernel.org>2022-11-29 13:04:52 -0800
commitf2bb566f5c977ff010baaa9e5e14d9a75b06e5f2 (patch)
tree6359cc9169bd06bfb8b757a534c82886df605b71 /arch/arm/mm/nommu.c
parent7a945ce0c19bbdf821d5f7ce1515e7fb8e444465 (diff)
parent01f856ae6d0ca5ad0505b79bf2d22d7ca439b2a1 (diff)
downloadlinux-f2bb566f5c977ff010baaa9e5e14d9a75b06e5f2.tar.bz2
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
tools/lib/bpf/ringbuf.c 927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap") b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c") https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/arm/mm/nommu.c')
-rw-r--r--arch/arm/mm/nommu.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index c42debaded95..c1494a4dee25 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -26,6 +26,13 @@
unsigned long vectors_base;
+/*
+ * empty_zero_page is a special page that is used for
+ * zero-initialized data and COW.
+ */
+struct page *empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
+
#ifdef CONFIG_ARM_MPU
struct mpu_rgn_info mpu_rgn_info;
#endif
@@ -148,9 +155,21 @@ void __init adjust_lowmem_bounds(void)
*/
void __init paging_init(const struct machine_desc *mdesc)
{
+ void *zero_page;
+
early_trap_init((void *)vectors_base);
mpu_setup();
+
+ /* allocate the zero page. */
+ zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ if (!zero_page)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE);
+
bootmem_init();
+
+ empty_zero_page = virt_to_page(zero_page);
+ flush_dcache_page(empty_zero_page);
}
/*