On Thu, 2015-08-20 at 17:04 -0600, Toshi Kani wrote: > On 8/20/2015 1:46 PM, Thomas Gleixner wrote: > > On Wed, 5 Aug 2015, Toshi Kani wrote: > > > > > In case of CONFIG_X86_64, vdso32/vclock_gettime.c fakes a 32bit > > > kernel configuration by re-defining it to CONFIG_X86_32. However, > > > it does not re-define CONFIG_PGTABLE_LEVELS leaving it as 4 levels. > > > Fix it by re-defining CONFIG_PGTABLE_LEVELS to 2 as X86_PAE is not > > > set. > > You fail to explain WHY this is required. I have not yet spotted any > > code in vclock_gettime.c which is affected by this. > > Sorry about that. Without this patch 01, applying patch 02 & 03 causes > the following compile errors in vclock_gettime.c. This is because it > includes pgtable_type.h (see blow), which now requires PUD_SHIFT and > PMD_SHIFT defined properly. In case of X86_32, pgtable_type.h includes > pgtable_nopud.h and pgtable-nopmd.h, which define these SHIFTs when > CONFIG_PGTABLE_LEVEL is set to 2 (or 3 if PAE is also defined). > : Attached is patch 01/10 with updated descriptions. The rest of the patchset still applies cleanly. Please let me know if you have any further comments. Thanks, -Toshi ---- Subject: [PATCH v3 UPDATE 1/10] x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSO In case of CONFIG_X86_64, vdso32/vclock_gettime.c fakes a 32-bit non-PAE kernel configuration by re-defining it to CONFIG_X86_32. However, it does not re-define CONFIG_PGTABLE_LEVELS leaving it as 4 levels. This mismatch leads <asm/pgtable_type.h> to NOT include <asm-generic/ pgtable-nopud.h> and <asm-generic/pgtable-nopmd.h>, which will cause compile errors when a later patch enhances <asm/pgtable_type.h> to use PUD_SHIFT and PMD_SHIFT. These -nopud & -nopmd headers define these SHIFTs for the 32-bit non-PAE kernel. Fix it by re-defining CONFIG_PGTABLE_LEVELS to 2 levels. Signed-off-by: Toshi Kani <toshi.kani@xxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> --- arch/x86/entry/vdso/vdso32/vclock_gettime.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c index 175cc72..87a86e0 100644 --- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c +++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c @@ -14,11 +14,13 @@ */ #undef CONFIG_64BIT #undef CONFIG_X86_64 +#undef CONFIG_PGTABLE_LEVELS #undef CONFIG_ILLEGAL_POINTER_VALUE #undef CONFIG_SPARSEMEM_VMEMMAP #undef CONFIG_NR_CPUS #define CONFIG_X86_32 1 +#define CONFIG_PGTABLE_LEVELS 2 #define CONFIG_PAGE_OFFSET 0 #define CONFIG_ILLEGAL_POINTER_VALUE 0 #define CONFIG_NR_CPUS 1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>