[PATCH 07/10] x86: make TASK_SIZE_MAX usable from assembly code
From: Christoph Hellwig <hch@lst.de>
Date: 2020-08-27 15:02:19
Also in:
linux-arch, linux-fsdevel, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
For 64-bit the only thing missing was a strategic _AC, and for 32-bit we need to use __PAGE_OFFSET instead of PAGE_OFFSET in the TASK_SIZE definition to escape the explicit unsigned long cast. This just works because __PAGE_OFFSET is defined using _AC itself and thus never needs the cast anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <redacted> --- arch/x86/include/asm/page_32_types.h | 4 ++-- arch/x86/include/asm/page_64_types.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
index 26236925fb2c36..f462895a33e452 100644
--- a/arch/x86/include/asm/page_32_types.h
+++ b/arch/x86/include/asm/page_32_types.h@@ -44,8 +44,8 @@ /* * User space process size: 3GB (default). */ -#define IA32_PAGE_OFFSET PAGE_OFFSET -#define TASK_SIZE PAGE_OFFSET +#define IA32_PAGE_OFFSET __PAGE_OFFSET +#define TASK_SIZE __PAGE_OFFSET #define TASK_SIZE_LOW TASK_SIZE #define TASK_SIZE_MAX TASK_SIZE #define DEFAULT_MAP_WINDOW TASK_SIZE
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 996595c9897e0a..838515daf87b36 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h@@ -76,7 +76,7 @@ * * With page table isolation enabled, we map the LDT in ... [stay tuned] */ -#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE) +#define TASK_SIZE_MAX ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE) #define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)
--
2.28.0