From: Baoquan He <bhe@redhat.com>
To: mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-doc@vger.kernel.org, tglx@linutronix.de,
thgarnie@google.com, corbet@lwn.net, Baoquan He <bhe@redhat.com>
Subject: [PATCH 1/3] x86/KASLR: Update KERNEL_IMAGE_SIZE description
Date: Sat, 6 Oct 2018 16:43:25 +0800 [thread overview]
Message-ID: <20181006084327.27467-2-bhe@redhat.com> (raw)
In-Reply-To: <20181006084327.27467-1-bhe@redhat.com>
Currently CONFIG_RANDOMIZE_BASE=y is set by default, which makes some of the
old comments above the KERNEL_IMAGE_SIZE definition out of date. Update them
to the current state of affairs.
Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/x86/include/asm/page_64_types.h | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 6afac386a434..cd0cf1c568b4 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -59,13 +59,16 @@
#endif
/*
- * Kernel image size is limited to 1GiB due to the fixmap living in the
- * next 1GiB (see level2_kernel_pgt in arch/x86/kernel/head_64.S). Use
- * 512MiB by default, leaving 1.5GiB for modules once the page tables
- * are fully set up. If kernel ASLR is configured, it can extend the
- * kernel page table mapping, reducing the size of the modules area.
+ * Maximum kernel image size is limited to 1 GiB, due to the fixmap living
+ * in the next 1 GiB (see level2_kernel_pgt in arch/x86/kernel/head_64.S).
+ *
+ * On KASLR use 1 GiB by default, leaving 1 GiB for modules once the
+ * page tables are fully set up.
+ *
+ * If KASLR is disabled we can shrink it to 0.5 GiB and increase the size
+ * of the modules area to 1.5 GiB.
*/
-#if defined(CONFIG_RANDOMIZE_BASE)
+#ifdef CONFIG_RANDOMIZE_BASE
#define KERNEL_IMAGE_SIZE (1024 * 1024 * 1024)
#else
#define KERNEL_IMAGE_SIZE (512 * 1024 * 1024)
--
2.13.6
next prev parent reply other threads:[~2018-10-06 8:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-06 8:43 [PATCH 0/3] x86/mm/doc: Clean up mm.txt Baoquan He
2018-10-06 8:43 ` Baoquan He [this message]
2018-10-06 13:06 ` [tip:x86/mm] x86/KASLR: Update KERNEL_IMAGE_SIZE description tip-bot for Baoquan He
2018-10-06 8:43 ` [PATCH 2/3] x86/mm/doc: Clean up the memory region layout descriptions Baoquan He
2018-10-06 13:07 ` [tip:x86/mm] x86/mm/doc: Clean up the x86-64 virtual memory " tip-bot for Baoquan He
2018-10-06 8:43 ` [PATCH 3/3] x86/doc/kaslr.txt: Create a separate part of document abourt KASLR at the end of file Baoquan He
2018-10-06 11:28 ` [PATCH 0/3] x86/mm/doc: Clean up mm.txt Baoquan He
2018-10-06 12:21 ` Ingo Molnar
2018-10-06 12:22 ` [PATCH 4/3] x86/mm/doc: Enhance the x86-64 virtual memory layout descriptions Ingo Molnar
2018-10-06 12:33 ` Ingo Molnar
2018-10-06 14:41 ` Baoquan He
2018-10-06 14:38 ` [PATCH 4/3 v2] " Ingo Molnar
2018-10-06 15:02 ` Baoquan He
2018-10-06 17:03 ` Ingo Molnar
2018-10-06 22:17 ` Andy Lutomirski
2018-10-09 0:35 ` Baoquan He
2018-10-09 4:48 ` Baoquan He
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