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x86/boot: Simplify pointer casting in choose_random_location()

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Pass them down as 'unsigned long' directly and get rid of more casting and
assignments.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: bhe@redhat.com
Cc: dyoung@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: luto@kernel.org
Cc: vgoyal@redhat.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20160506115015.GI24044@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Borislav Petkov 2016-05-06 13:50:15 +02:00 committed by Ingo Molnar
parent 9dc1969c24
commit 549f90db68
3 changed files with 13 additions and 17 deletions
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17
arch/x86/boot/compressed/kaslr.c
View file

@ -350,20 +350,15 @@ static unsigned long find_random_addr(unsigned long minimum,
return slots_fetch_random();
}
unsigned char *choose_random_location(unsigned char *input_ptr,
/*
* Since this function examines addresses much more numerically,
* it takes the input and output pointers as 'unsigned long'.
*/
unsigned char *choose_random_location(unsigned long input,
unsigned long input_size,
unsigned char *output_ptr,
unsigned long output,
unsigned long output_size)
{
/*
* The caller of choose_random_location() uses unsigned char * for
* buffer pointers since it performs decompression, elf parsing, etc.
* Since this code examines addresses much more numerically,
* unsigned long is used internally here. Instead of sprinkling
* more casts into extract_kernel, do them here and at return.
*/
unsigned long input = (unsigned long)input_ptr;
unsigned long output = (unsigned long)output_ptr;
unsigned long choice = output;
unsigned long random_addr;

3
arch/x86/boot/compressed/misc.c
View file

@ -366,7 +366,8 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
* the entire decompressed kernel plus relocation table, or the
* entire decompressed kernel plus .bss and .brk sections.
*/
output = choose_random_location(input_data, input_len, output,
output = choose_random_location((unsigned long)input_data, input_len,
(unsigned long)output,
max(output_len, kernel_total_size));
/* Validate memory location choices. */

10
arch/x86/boot/compressed/misc.h
View file

@ -67,20 +67,20 @@ int cmdline_find_option_bool(const char *option);
#if CONFIG_RANDOMIZE_BASE
/* kaslr.c */
unsigned char *choose_random_location(unsigned char *input_ptr,
unsigned char *choose_random_location(unsigned long input_ptr,
unsigned long input_size,
unsigned char *output_ptr,
unsigned long output_ptr,
unsigned long output_size);
/* cpuflags.c */
bool has_cpuflag(int flag);
#else
static inline
unsigned char *choose_random_location(unsigned char *input_ptr,
unsigned char *choose_random_location(unsigned long input_ptr,
unsigned long input_size,
unsigned char *output_ptr,
unsigned long output_ptr,
unsigned long output_size)
{
return output_ptr;
return (unsigned char *)output_ptr;
}
#endif