Messages in this thread Patch in this message | | | Subject | [PATCH 3/7] x86/mm/init: pass unconverted symbol addresses to free_init_pages() | From | Dave Hansen <> | Date | Thu, 02 Aug 2018 15:58:28 -0700 |
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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(); _
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