diff options
Diffstat (limited to 'arch/um/include/as-layout.h')
| -rw-r--r-- | arch/um/include/as-layout.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/um/include/as-layout.h b/arch/um/include/as-layout.h index 2b859e0..a2008f5 100644 --- a/arch/um/include/as-layout.h +++ b/arch/um/include/as-layout.h @@ -29,9 +29,20 @@ #define _AC(X, Y) __AC(X, Y) #endif +/* + * The "- 1"'s are to avoid gcc complaining about integer overflows + * and unrepresentable decimal constants. With 3-level page tables, + * TASK_SIZE is 0x80000000, which gets turned into its signed decimal + * equivalent in asm-offsets.s. gcc then complains about that being + * unsigned only in C90. To avoid that, UM_TASK_SIZE is defined as + * TASK_SIZE - 1. To compensate, we need to add the 1 back here. + * However, adding it back to UM_TASK_SIZE produces more gcc + * complaints. So, I adjust the thing being subtracted from + * UM_TASK_SIZE instead. Bah. + */ #define STUB_CODE _AC((unsigned long), \ - UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE) -#define STUB_DATA _AC((unsigned long), UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE) + UM_TASK_SIZE - (2 * UM_KERN_PAGE_SIZE - 1)) +#define STUB_DATA _AC((unsigned long), UM_TASK_SIZE - (UM_KERN_PAGE_SIZE - 1)) #define STUB_START _AC(, STUB_CODE) #ifndef __ASSEMBLY__ |