On Tue, Mar 24, 2015 at 07:00:48PM +0100, Hector Marco-Gisbert wrote:
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index 15c5df9..a693d54 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -5,6 +5,7 @@
>
> #include <linux/io.h>
> #include <linux/sched.h>
> +#include <linux/random.h>
> #include <asm/processor.h>
> #include <asm/apic.h>
> #include <asm/cpu.h>
> @@ -18,6 +19,8 @@
>
> #include "cpu.h"
>
> +unsigned long rnd_bulldozer_bits = 0;
> +
> static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
> {
> u32 gprs[8] = { 0 };
> @@ -488,6 +491,8 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
>
> va_align.mask = (upperbit - 1) & PAGE_MASK;
> va_align.flags = ALIGN_VA_32 | ALIGN_VA_64;
> + /* A random value per boot for bits 12,13 and 14 */
> + rnd_bulldozer_bits = get_random_int() & va_align.mask;
Hmm, this should be done differently:
va_align should have a ->bits member which gets ORed in into the hole
made my va_align.mask...
> }
> }
>
> diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
> index 30277e2..5b8ad01 100644
> --- a/arch/x86/kernel/sys_x86_64.c
> +++ b/arch/x86/kernel/sys_x86_64.c
> @@ -18,6 +18,7 @@
>
> #include <asm/ia32.h>
> #include <asm/syscalls.h>
> +#include <asm/amd_15h.h>
>
> /*
> * Align a virtual address to avoid aliasing in the I$ on AMD F15h.
> @@ -34,10 +35,16 @@ static unsigned long get_align_mask(void)
> return va_align.mask;
> }
>
> +static unsigned long get_bulldozer_bits(void){
> +
> + return rnd_bulldozer_bits & get_align_mask();
> +}
> +
> unsigned long align_vdso_addr(unsigned long addr)
> {
> unsigned long align_mask = get_align_mask();
> - return (addr + align_mask) & ~align_mask;
> + addr = (addr + align_mask) & ~align_mask;
> + return addr | get_bulldozer_bits();
> }
>
> static int __init control_va_addr_alignment(char *str)
> @@ -137,7 +144,10 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
> info.high_limit = end;
> info.align_mask = filp ? get_align_mask() : 0;
info.align_bits = get_align_bits() : 0;
> info.align_offset = pgoff << PAGE_SHIFT;
> - return vm_unmapped_area(&info);
> + addr = vm_unmapped_area(&info);
> + if (!(addr & ~PAGE_MASK))
> + return filp ? (addr|get_bulldozer_bits()) : addr;
> + return addr;
> }
>
> unsigned long
> @@ -178,7 +188,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
> info.align_offset = pgoff << PAGE_SHIFT;
> addr = vm_unmapped_area(&info);
> if (!(addr & ~PAGE_MASK))
> - return addr;
> + return filp ? (addr|get_bulldozer_bits()) : addr;
Ditto.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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