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| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2008-10-15 18:46:27 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-15 20:20:14 +0400 |
| commit | f61f1b5717dec9968efd6c8d61bd73b7a61b72a0 (patch) | |
| tree | 634419373c9bb3c545cefdebdc8b998f2aa01f6b | |
| parent | 3a1dfe6eefe483589c99c909202ffe1a20d589b5 (diff) | |
| download | linux-f61f1b5717dec9968efd6c8d61bd73b7a61b72a0.tar.xz | |
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>
| -rw-r--r-- | include/asm-x86/pgtable.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index ed932453ef26..e9f10af50f49 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -138,8 +138,13 @@ #ifdef CONFIG_X86_64 #define __PAGE_KERNEL_IDENT_LARGE_EXEC __PAGE_KERNEL_LARGE_EXEC #else +/* + * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection + * bits are combined, this will alow user to access the high address mapped + * VDSO in the presence of CONFIG_COMPAT_VDSO + */ #define PTE_IDENT_ATTR 0x003 /* PRESENT+RW */ -#define PDE_IDENT_ATTR 0x063 /* PRESENT+RW+DIRTY+ACCESSED */ +#define PDE_IDENT_ATTR 0x067 /* PRESENT+RW+USER+DIRTY+ACCESSED */ #define PGD_IDENT_ATTR 0x001 /* PRESENT (no other attributes) */ #endif |