From: Baoquan He <bhe@redhat.com>
To: linux-kernel@vger.kernel.org, mingo@kernel.org,
lcapitulino@redhat.com, keescook@chromium.org,
tglx@linutronix.de
Cc: x86@kernel.org, hpa@zytor.com, fanc.fnst@cn.fujitsu.com,
yasu.isimatu@gmail.com, indou.takao@jp.fujitsu.com,
douly.fnst@cn.fujitsu.com, Baoquan He <bhe@redhat.com>
Subject: [PATCH 1/2] x86/boot/KASLR: Add two functions for 1GB huge pages handling
Date: Wed, 16 May 2018 18:05:31 +0800 [thread overview]
Message-ID: <20180516100532.14083-2-bhe@redhat.com> (raw)
In-Reply-To: <20180516100532.14083-1-bhe@redhat.com>
Functions parse_gb_huge_pages() and process_gb_huge_page() are introduced to
handle conflict between KASLR and huge pages, will be used in the next patch.
Function parse_gb_huge_pages() is used to parse kernel command-line to get
how many 1GB huge pages have been specified. A static global variable
'max_gb_huge_pages' is added to store the number.
And process_gb_huge_page() is used to skip as many 1GB huge pages as possible
from the passed in memory region according to the specified number.
Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/x86/boot/compressed/kaslr.c | 71 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 71 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index a0a50b91ecef..13bd879cdc5d 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -215,6 +215,32 @@ static void mem_avoid_memmap(char *str)
memmap_too_large = true;
}
+/* Store the number of 1GB huge pages which user specified.*/
+static unsigned long max_gb_huge_pages;
+
+static int parse_gb_huge_pages(char *param, char* val)
+{
+ char *p;
+ u64 mem_size;
+ static bool gbpage_sz = false;
+
+ if (!strcmp(param, "hugepagesz")) {
+ p = val;
+ mem_size = memparse(p, &p);
+ if (mem_size == PUD_SIZE) {
+ if (gbpage_sz)
+ warn("Repeadly set hugeTLB page size of 1G!\n");
+ gbpage_sz = true;
+ } else
+ gbpage_sz = false;
+ } else if (!strcmp(param, "hugepages") && gbpage_sz) {
+ p = val;
+ max_gb_huge_pages = simple_strtoull(p, &p, 0);
+ debug_putaddr(max_gb_huge_pages);
+ }
+}
+
+
static int handle_mem_memmap(void)
{
char *args = (char *)get_cmd_line_ptr();
@@ -466,6 +492,51 @@ static void store_slot_info(struct mem_vector *region, unsigned long image_size)
}
}
+/* Skip as many 1GB huge pages as possible in the passed region. */
+static void process_gb_huge_page(struct mem_vector *region, unsigned long image_size)
+{
+ int i = 0;
+ unsigned long addr, size;
+ struct mem_vector tmp;
+
+ if (!max_gb_huge_pages) {
+ store_slot_info(region, image_size);
+ return;
+ }
+
+ addr = ALIGN(region->start, PUD_SIZE);
+ /* If Did we raise the address above the passed in memory entry? */
+ if (addr < region->start + region->size)
+ size = region->size - (addr - region->start);
+
+ /* Check how many 1GB huge pages can be filtered out*/
+ while (size > PUD_SIZE && max_gb_huge_pages) {
+ size -= PUD_SIZE;
+ max_gb_huge_pages--;
+ i++;
+ }
+
+ if (!i) {
+ store_slot_info(region, image_size);
+ return;
+ }
+
+ /* Process the remaining regions after filtering out. */
+
+ if (addr >= region->start + image_size) {
+ tmp.start = region->start;
+ tmp.size = addr - region->start;
+ store_slot_info(&tmp, image_size);
+ }
+
+ size = region->size - (addr - region->start) - i * PUD_SIZE;
+ if (size >= image_size) {
+ tmp.start = addr + i*PUD_SIZE;
+ tmp.size = size;
+ store_slot_info(&tmp, image_size);
+ }
+}
+
static unsigned long slots_fetch_random(void)
{
unsigned long slot;
--
2.13.6
next prev parent reply other threads:[~2018-05-16 10:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-16 10:05 [PATCH 0/2] x86/boot/KASLR: Skip specified number of 1GB huge pages when do physical randomization Baoquan He
2018-05-16 10:05 ` Baoquan He [this message]
2018-05-17 3:27 ` [PATCH 1/2] x86/boot/KASLR: Add two functions for 1GB huge pages handling Chao Fan
2018-05-17 4:03 ` Baoquan He
2018-05-17 5:53 ` Chao Fan
2018-05-17 6:13 ` Baoquan He
2018-05-17 5:12 ` damian
2018-05-17 5:38 ` Baoquan He
2018-06-21 15:01 ` Ingo Molnar
2018-06-22 12:14 ` Baoquan He
2018-06-24 7:13 ` Ingo Molnar
2018-05-16 10:05 ` [PATCH 2/2] x86/boot/KASLR: Skip specified number of 1GB huge pages when do physical randomization Baoquan He
2018-05-18 7:00 ` [PATCH 0/2] " Ingo Molnar
2018-05-18 7:43 ` Baoquan He
2018-05-18 8:19 ` Ingo Molnar
2018-05-18 11:28 ` Baoquan He
2018-05-18 12:14 ` Baoquan He
2018-05-23 19:10 ` Luiz Capitulino
2018-05-28 9:54 ` Baoquan He
2018-05-29 13:27 ` Luiz Capitulino
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