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 3/7] x86/mm/init: pass unconverted symbol addresses to free_init_pages()
Date: Thu, 02 Aug 2018 15:58:28 -0700 [thread overview]
Message-ID: <20180802225828.89B2D0E2@viggo.jf.intel.com> (raw)
In-Reply-To: <20180802225823.4711C55B@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
The x86 code has several places where it frees parts of kernel image:
1. Unused SMP alternative
2. __init code
3. The hole between text and rodata
4. The hole between rodata and data
We call free_init_pages() to do this. Strangely, we convert the
symbol addresses to kernel direct map addresses in some cases
(#3, #4) but not others (#1, #2).
The virt_to_page() and the other code in free_reserved_area() now
works fine for for symbol addresses on x86, so don't bother
converting the addresses to direct map addresses before freeing
them.
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/mm/init_64.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff -puN arch/x86/mm/init_64.c~x86-init-do-not-convert-symbol-addresses arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~x86-init-do-not-convert-symbol-addresses 2018-08-02 14:14:48.380483277 -0700
+++ b/arch/x86/mm/init_64.c 2018-08-02 14:14:48.383483277 -0700
@@ -1283,12 +1283,8 @@ void mark_rodata_ro(void)
set_memory_ro(start, (end-start) >> PAGE_SHIFT);
#endif
- free_init_pages("unused kernel",
- (unsigned long) __va(__pa_symbol(text_end)),
- (unsigned long) __va(__pa_symbol(rodata_start)));
- free_init_pages("unused kernel",
- (unsigned long) __va(__pa_symbol(rodata_end)),
- (unsigned long) __va(__pa_symbol(_sdata)));
+ free_init_pages("unused kernel", text_end, rodata_start);
+ free_init_pages("unused kernel", rodata_end, _sdata);
debug_checkwx();
_
next prev parent reply other threads:[~2018-08-02 22:58 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-02 22:58 [PATCH 0/7] [v2] x86/mm/pti: close two Meltdown leaks with Global kernel mapping Dave Hansen
2018-08-02 22:58 ` [PATCH 1/7] x86/mm/pti: clear Global bit more aggressively Dave Hansen
2018-08-05 20:30 ` [tip:x86/pti] x86/mm/pti: Clear " tip-bot for Dave Hansen
2018-08-02 22:58 ` [PATCH 2/7] mm: allow non-direct-map arguments to free_reserved_area() Dave Hansen
2018-08-05 20:31 ` [tip:x86/pti] mm: Allow " tip-bot for Dave Hansen
2018-08-02 22:58 ` Dave Hansen [this message]
2018-08-04 0:18 ` [PATCH 3/7] x86/mm/init: pass unconverted symbol addresses to free_init_pages() Hugh Dickins
2018-08-04 17:31 ` Linus Torvalds
2018-08-04 18:23 ` Hugh Dickins
2018-08-05 6:11 ` Andi Kleen
2018-08-05 20:31 ` [tip:x86/pti] x86/mm/init: Pass " tip-bot for Dave Hansen
2018-08-02 22:58 ` [PATCH 4/7] x86/mm/init: add helper for freeing kernel image pages Dave Hansen
2018-08-05 20:32 ` [tip:x86/pti] x86/mm/init: Add " tip-bot for Dave Hansen
2018-08-02 22:58 ` [PATCH 5/7] x86/mm/init: remove freed kernel image areas from alias mapping Dave Hansen
2018-08-04 0:35 ` Hugh Dickins
2018-08-04 21:38 ` Andy Lutomirski
2018-08-06 15:17 ` Dave Hansen
2018-08-05 20:32 ` [tip:x86/pti] x86/mm/init: Remove " tip-bot for Dave Hansen
2018-08-06 20:21 ` [tip:x86/pti-urgent] " tip-bot for Dave Hansen
2018-08-02 22:58 ` [PATCH 6/7] x86/mm/pageattr: pass named flag instead of 0/1 Dave Hansen
2018-08-05 20:09 ` Thomas Gleixner
2018-08-06 15:09 ` Dave Hansen
2018-08-02 22:58 ` [PATCH 7/7] x86/mm/pageattr: Remove implicit NX behavior Dave Hansen
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