x86: fix compat-vdso
Jeff Chua reported that this patch:
> -#define PTE_IDENT_ATTR 0x007 /* PRESENT+RW+USER */
> -#define PDE_IDENT_ATTR 0x067 /* PRESENT+RW+USER+DIRTY+ACCESSED */
> +#define PTE_IDENT_ATTR 0x003 /* PRESENT+RW */
> +#define PDE_IDENT_ATTR 0x063 /* PRESENT+RW+DIRTY+ACCESSED */
broke kernels with CONFIG_COMPAT_VDSO set with this init segfault:
init[1]: segfault at ffffe01c up b7f0dc28 sp bfc26628 error 5 in ld-2.7.90.so[b7f0b000+1c000]
Include USER bit in the PDE_IDENT_ATTR only, as the protection bits
are combined from the PDE and PTE entries. This will allow the high
mapped VDSO page in the case of CONFIG_COMPAT_VDSO to be user
readable.
Reported-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed