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Message-Id: <681844dc69a3b746e92a685b706595bff7613481.1684137557.git.houwenlong.hwl@antgroup.com>
Date: Mon, 15 May 2023 16:19:35 +0800
From: "Hou Wenlong" <houwenlong.hwl@...group.com>
To: linux-kernel@...r.kernel.org
Cc: "Lai Jiangshan" <jiangshan.ljs@...group.com>,
"Hou Wenlong" <houwenlong.hwl@...group.com>,
"Thomas Gleixner" <tglx@...utronix.de>,
"Ingo Molnar" <mingo@...hat.com>, "Borislav Petkov" <bp@...en8.de>,
"Dave Hansen" <dave.hansen@...ux.intel.com>, <x86@...nel.org>,
"H. Peter Anvin" <hpa@...or.com>,
"Andy Lutomirski" <luto@...nel.org>,
"Peter Zijlstra" <peterz@...radead.org>,
"Juergen Gross" <jgross@...e.com>,
"Anshuman Khandual" <anshuman.khandual@....com>,
"Mike Rapoport" <rppt@...nel.org>,
"Josh Poimboeuf" <jpoimboe@...nel.org>,
"Pasha Tatashin" <pasha.tatashin@...een.com>
Subject: [PATCH RFC 4/4] x86/fixmap: Unify FIXADDR_TOP
Since FIXADDR_TOP is unrelated to the vsyscall page now, it can be
declared as a variable for x86_64, thereby unifying it for x86.
Suggested-by: Lai Jiangshan <jiangshan.ljs@...group.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@...group.com>
---
arch/x86/include/asm/fixmap.h | 13 -------------
arch/x86/kernel/head64.c | 1 -
arch/x86/mm/dump_pagetables.c | 3 ++-
arch/x86/mm/ioremap.c | 5 ++---
arch/x86/mm/pgtable.c | 13 +++++++++++++
arch/x86/mm/pgtable_32.c | 3 ---
6 files changed, 17 insertions(+), 21 deletions(-)
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index eeb152ad9682..9433109e4853 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -40,21 +40,8 @@
#include <linux/threads.h>
#endif
-/*
- * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
- * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
- * Because of this, FIXADDR_TOP x86 integration was left as later work.
- */
-#ifdef CONFIG_X86_32
-/*
- * Leave one empty page between vmalloc'ed areas and
- * the start of the fixmap.
- */
extern unsigned long __FIXADDR_TOP;
#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
-#else
-#define FIXADDR_TOP (0xffffffffff600000UL - PAGE_SIZE)
-#endif
/*
* Here we define all the compile-time 'special' virtual
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 49f7629b17f7..34fc86e81872 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -485,7 +485,6 @@ asmlinkage __visible void __init __noreturn x86_64_start_kernel(char * real_mode
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
(__START_KERNEL & PGDIR_MASK)));
- BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
cr4_init_shadow();
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index e1b599ecbbc2..df1a708a038a 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -104,7 +104,7 @@ static struct addr_marker address_markers[] = {
[HIGH_KERNEL_NR] = { __START_KERNEL_map, "High Kernel Mapping" },
[MODULES_VADDR_NR] = { MODULES_VADDR, "Modules" },
[MODULES_END_NR] = { MODULES_END, "End Modules" },
- [FIXADDR_START_NR] = { FIXADDR_START, "Fixmap Area" },
+ [FIXADDR_START_NR] = { 0UL, "Fixmap Area" },
[END_OF_SPACE_NR] = { -1, NULL }
};
@@ -453,6 +453,7 @@ static int __init pt_dump_init(void)
address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START;
address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END;
#endif
+ address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
#endif
#ifdef CONFIG_X86_32
address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index aa7d279321ea..44f9c6781c15 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -879,10 +879,9 @@ void __init early_ioremap_init(void)
pmd_t *pmd;
#ifdef CONFIG_X86_64
- BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
-#else
- WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+ BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
#endif
+ WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
early_ioremap_setup();
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index e4f499eb0f29..2d73db9c7cbc 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -627,6 +627,19 @@ pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address,
}
#endif
+#ifdef CONFIG_X86_32
+/*
+ * Leave one empty page between vmalloc'ed areas and
+ * the start of the fixmap.
+ */
+#define __FIXADDR_TOP_BASE 0xfffff000
+#else
+#define __FIXADDR_TOP_BASE (0xffffffffff600000UL - PAGE_SIZE)
+#endif
+
+unsigned long __FIXADDR_TOP = __FIXADDR_TOP_BASE;
+EXPORT_SYMBOL(__FIXADDR_TOP);
+
/**
* reserve_top_address - reserves a hole in the top of kernel address space
* @reserve - size of hole to reserve
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
index c234634e26ba..2b9a00976fee 100644
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -65,9 +65,6 @@ void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
flush_tlb_one_kernel(vaddr);
}
-unsigned long __FIXADDR_TOP = 0xfffff000;
-EXPORT_SYMBOL(__FIXADDR_TOP);
-
/*
* vmalloc=size forces the vmalloc area to be exactly 'size'
* bytes. This can be used to increase (or decrease) the
--
2.31.1
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