[PATCH v5 1/2] x86_64: remove not needed clear_page for init_level4_page

[Alexander Popov <alpopov@ptsecurity.com>]

From: Andrey Ryabinin <a.ryabinin@samsung.com>

Commit 8170e6bed465 ("x86, 64bit: Use a #PF handler to materialize
early mappings on demand") introduced clear_page(init_level4_pgt);
call in x86_64_start_kernel(). However, this clear_page is useless
because init_level4_page already filled with zeroes in head_64.S

Commit message in 8170e6bed465 says that this clear_page() was
dropped in v7, but it accidentally reappeared in later versions
of that patchset.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
---
 arch/x86/kernel/head64.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 5a46681..6a6eefd 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -177,7 +177,6 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 	 */
 	load_ucode_bsp();
 
-	clear_page(init_level4_pgt);
 	/* set init_level4_pgt kernel high mapping*/
 	init_level4_pgt[511] = early_level4_pgt[511];
 
-- 
1.9.1