[PATCH 06/10] x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h

Christoph Hellwig
2020-08-27T15:09:27Z

At least for 64-bit this moves them closer to some of the defines
they are based on, and it prepares for using the TASK_SIZE_MAX
definition from assembly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/x86/include/asm/page_32_types.h | 11 +++++++
arch/x86/include/asm/page_64_types.h | 38 +++++++++++++++++++++
arch/x86/include/asm/processor.h | 49 ----------------------------
3 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
index 565ad755c785e2..26236925fb2c36 100644
--- a/arch/x86/include/asm/page_32_types.h
+++ b/arch/x86/include/asm/page_32_types.h
@@ -41,6 +41,17 @@
#define __VIRTUAL_MASK_SHIFT 32
#endif /* CONFIG_X86_PAE */

+/*
+ * User space process size: 3GB (default).
+ */
+#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
+#define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX STACK_TOP
+
/*
* Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S)
*/
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 288b065955b729..996595c9897e0a 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -58,6 +58,44 @@
#define __VIRTUAL_MASK_SHIFT 47
#endif

+/*
+ * User space process size. This is the first address outside the user range.
+ * There are a few constraints that determine this:
+ *
+ * On Intel CPUs, if a SYSCALL instruction is at the highest canonical
+ * address, then that syscall will enter the kernel with a
+ * non-canonical return address, and SYSRET will explode dangerously.
+ * We avoid this particular problem by preventing anything executable
+ * from being mapped at the maximum canonical address.
+ *
+ * On AMD CPUs in the Ryzen family, there's a nasty bug in which the
+ * CPUs malfunction if they execute code from the highest canonical page.
+ * They'll speculate right off the end of the canonical space, and
+ * bad things happen. This is worked around in the same way as the
+ * Intel problem.
+ *
+ * With page table isolation enabled, we map the LDT in ... [stay tuned]
+ */
+#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
+
+#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \
+ 0xc0000000 : 0xFFFFe000)
+
+#define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \
+ IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
+#define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \
+ IA32_PAGE_OFFSET : TASK_SIZE_MAX)
+#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
+ IA32_PAGE_OFFSET : TASK_SIZE_MAX)
+
+#define STACK_TOP TASK_SIZE_LOW
+#define STACK_TOP_MAX TASK_SIZE_MAX
+
/*
* Maximum kernel image size is limited to 1 GiB, due to the fixmap living
* in the next 1 GiB (see level2_kernel_pgt in arch/x86/kernel/head_64.S).
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 97143d87994c24..1618eeb08361a9 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -782,17 +782,6 @@ static inline void spin_lock_prefetch(const void *x)
})

#ifdef CONFIG_X86_32
-/*
- * User space process size: 3GB (default).
- */
-#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
-#define STACK_TOP TASK_SIZE
-#define STACK_TOP_MAX STACK_TOP
-
#define INIT_THREAD { \
.sp0 = TOP_OF_INIT_STACK, \
.sysenter_cs = __KERNEL_CS, \
@@ -802,44 +791,6 @@ static inline void spin_lock_prefetch(const void *x)
#define KSTK_ESP(task) (task_pt_regs(task)->sp)

#else
-/*
- * User space process size. This is the first address outside the user range.
- * There are a few constraints that determine this:
- *
- * On Intel CPUs, if a SYSCALL instruction is at the highest canonical
- * address, then that syscall will enter the kernel with a
- * non-canonical return address, and SYSRET will explode dangerously.
- * We avoid this particular problem by preventing anything executable
- * from being mapped at the maximum canonical address.
- *
- * On AMD CPUs in the Ryzen family, there's a nasty bug in which the
- * CPUs malfunction if they execute code from the highest canonical page.
- * They'll speculate right off the end of the canonical space, and
- * bad things happen. This is worked around in the same way as the
- * Intel problem.
- *
- * With page table isolation enabled, we map the LDT in ... [stay tuned]
- */
-#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
-
-#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)
-
-/* This decides where the kernel will search for a free chunk of vm
- * space during mmap's.
- */
-#define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \
- 0xc0000000 : 0xFFFFe000)
-
-#define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \
- IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
-#define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \
- IA32_PAGE_OFFSET : TASK_SIZE_MAX)
-#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
- IA32_PAGE_OFFSET : TASK_SIZE_MAX)
-
-#define STACK_TOP TASK_SIZE_LOW
-#define STACK_TOP_MAX TASK_SIZE_MAX
-
#define INIT_THREAD { \
.addr_limit = KERNEL_DS, \
}
--
2.28.0