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From: Baoquan He <bhe@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, keescook@chromium.org, kirill@shutemov.name,
	yamada.masahiro@socionext.com, tglx@linutronix.de, bp@alien8.de,
	hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org,
	peterz@infradead.org, x86@kernel.org, thgarnie@google.com,
	Baoquan He <bhe@redhat.com>
Subject: [PATCH v4 2/6] x86/mm/KASLR: Open code unnecessary function get_padding
Date: Thu, 14 Mar 2019 17:46:41 +0800	[thread overview]
Message-ID: <20190314094645.4883-3-bhe@redhat.com> (raw)
In-Reply-To: <20190314094645.4883-1-bhe@redhat.com>

It's used only twice and we do bit shifts in the parent function
anyway so it's not like it's hiding some uninteresting detail.

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/mm/kaslr.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 5debf82ab06a..d7ea6b252594 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -92,12 +92,6 @@ static __initdata struct kaslr_memory_region {
 	{ &vmemmap_base, 1 },
 };
 
-/* Get size in bytes used by the memory region */
-static inline unsigned long get_padding(struct kaslr_memory_region *region)
-{
-	return (region->size_tb << TB_SHIFT);
-}
-
 /*
  * Apply no randomization if KASLR was disabled at boot or if KASAN
  * is enabled. KASAN shadow mappings rely on regions being PGD aligned.
@@ -155,7 +149,7 @@ void __init kernel_randomize_memory(void)
 	/* Calculate entropy available between regions */
 	remain_entropy = vaddr_end - vaddr_start;
 	for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++)
-		remain_entropy -= get_padding(&kaslr_regions[i]);
+		remain_entropy -= kaslr_regions[i].size_tb << TB_SHIFT;
 
 	prandom_seed_state(&rand_state, kaslr_get_random_long("Memory"));
 
@@ -176,7 +170,7 @@ void __init kernel_randomize_memory(void)
 		 * Jump the region and add a minimum padding based on
 		 * randomization alignment.
 		 */
-		vaddr += get_padding(&kaslr_regions[i]);
+		vaddr += kaslr_regions[i].size_tb << TB_SHIFT;
 		vaddr = round_up(vaddr + 1, PUD_SIZE);
 		remain_entropy -= entropy;
 	}
-- 
2.17.2


  parent reply	other threads:[~2019-03-14  9:47 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-14  9:46 [PATCH v4 0/6] Several patches to fix code bugs, improve documents and clean up Baoquan He
2019-03-14  9:46 ` [PATCH v4 1/6] x86/mm/KASLR: Improve code comments about struct kaslr_memory_region Baoquan He
2019-03-14  9:46 ` Baoquan He [this message]
2019-03-14  9:46 ` [PATCH v4 3/6] mm: Add build time sanity check for struct page size Baoquan He
2019-03-14  9:50   ` Baoquan He
2019-03-14  9:57     ` Baoquan He
2019-03-14  9:46 ` [PATCH v4 4/6] x86/mm/KASLR: Fix the wrong calculation of memory region initial size Baoquan He
2019-03-24 20:58   ` Thomas Gleixner
2019-03-25  3:46     ` Baoquan He
2019-03-14  9:46 ` [PATCH v4 5/6] x86/mm/KASLR: Calculate the actual size of vmemmap region Baoquan He
2019-03-14  9:46 ` [PATCH v4 6/6] x86/mm/KASLR: Do not adapt the size of the direct mapping region for SGI UV system Baoquan He

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