From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
keescook@google.com, tglx@linutronix.de, mingo@kernel.org,
aarcange@redhat.com, jgross@suse.com, jpoimboe@redhat.com,
gregkh@linuxfoundation.org, peterz@infradead.org,
hughd@google.com, torvalds@linux-foundation.org, bp@alien8.de,
luto@kernel.org, ak@linux.intel.com
Subject: [PATCH 4/5] x86/mm/init: add helper for freeing kernel image pages
Date: Wed, 01 Aug 2018 11:01:03 -0700 [thread overview]
Message-ID: <20180801180103.E42368F9@viggo.jf.intel.com> (raw)
In-Reply-To: <20180801180058.EC46D963@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
When chunks of the kernel image are freed, free_init_pages()
is used directly. Consolidate the three sites that do this.
Also update the string to give an incrementally better
description of that memory versus what was there before.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
---
b/arch/x86/include/asm/processor.h | 1 +
b/arch/x86/mm/init.c | 15 ++++++++++++---
b/arch/x86/mm/init_64.c | 4 ++--
3 files changed, 15 insertions(+), 5 deletions(-)
diff -puN arch/x86/include/asm/processor.h~x86-mm-init-common-kernel-image-free-helper arch/x86/include/asm/processor.h
--- a/arch/x86/include/asm/processor.h~x86-mm-init-common-kernel-image-free-helper 2018-07-30 09:53:14.295915691 -0700
+++ b/arch/x86/include/asm/processor.h 2018-07-30 09:53:14.303915690 -0700
@@ -975,6 +975,7 @@ static inline uint32_t hypervisor_cpuid_
extern unsigned long arch_align_stack(unsigned long sp);
extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
+extern void free_kernel_image_pages(void *begin, void *end);
void default_idle(void);
#ifdef CONFIG_XEN
diff -puN arch/x86/mm/init_64.c~x86-mm-init-common-kernel-image-free-helper arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~x86-mm-init-common-kernel-image-free-helper 2018-07-30 09:53:14.297915691 -0700
+++ b/arch/x86/mm/init_64.c 2018-07-30 09:53:14.304915690 -0700
@@ -1283,8 +1283,8 @@ void mark_rodata_ro(void)
set_memory_ro(start, (end-start) >> PAGE_SHIFT);
#endif
- free_init_pages("unused kernel", text_end, rodata_start);
- free_init_pages("unused kernel", rodata_end, _sdata);
+ free_kernel_image_pages((void *)text_end, (void *)rodata_start);
+ free_kernel_image_pages((void *)rodata_end, (void *)_sdata);
debug_checkwx();
diff -puN arch/x86/mm/init.c~x86-mm-init-common-kernel-image-free-helper arch/x86/mm/init.c
--- a/arch/x86/mm/init.c~x86-mm-init-common-kernel-image-free-helper 2018-07-30 09:53:14.298915691 -0700
+++ b/arch/x86/mm/init.c 2018-07-30 09:53:14.304915690 -0700
@@ -771,13 +771,22 @@ void free_init_pages(char *what, unsigne
}
}
+/*
+ * begin/end can be in the direct map or the "high kernel mapping"
+ * used for the kernel image only. free_init_pages() will do the
+ * right thing for either kind of address.
+ */
+void free_kernel_image_pages(void *begin, void *end)
+{
+ free_init_pages("unused kernel image",
+ (unsigned long)begin, (unsigned long)end);
+}
+
void __ref free_initmem(void)
{
e820__reallocate_tables();
- free_init_pages("unused kernel",
- (unsigned long)(&__init_begin),
- (unsigned long)(&__init_end));
+ free_kernel_image_pages(&__init_begin, &__init_end);
}
#ifdef CONFIG_BLK_DEV_INITRD
_
next prev parent reply other threads:[~2018-08-01 18:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 18:00 [PATCH 0/5] x86/mm/pti: close two Meltdown leaks with Global kernel mapping Dave Hansen
2018-08-01 18:00 ` [PATCH 1/5] x86/mm/pti: clear Global bit more aggressively Dave Hansen
2018-08-01 18:01 ` [PATCH 2/5] mm: allow non-direct-map arguments to free_reserved_area() Dave Hansen
2018-08-01 18:01 ` [PATCH 3/5] x86/mm/init: pass unconverted symbol addresses to free_init_pages() Dave Hansen
2018-08-01 18:01 ` Dave Hansen [this message]
2018-08-01 18:01 ` [PATCH 5/5] x86/mm/init: remove freed kernel image areas from alias mapping Dave Hansen
2018-08-01 23:16 ` Hugh Dickins
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