From: Jeff Dike Date: Tue, 5 Feb 2008 06:31:00 +0000 (-0800) Subject: uml: clean up TASK_SIZE usage X-Git-Tag: v2.6.25-rc1~832 X-Git-Url: http://ftp.safe.ca/?a=commitdiff_plain;h=42a2b54ce8c7b9d4f418995a7950e7e2e15e52ce;p=safe%2Fjmp%2Flinux-2.6 uml: clean up TASK_SIZE usage Clean up the calculation and use of the usable address space size on the host. task_size is gone, replaced with TASK_SIZE, which is calculated from CONFIG_TOP_ADDR. get_kmem_end and set_task_sizes_skas are also gone. host_task_size, which refers to the entire address space usable by the UML kernel and which may be larger than the address space usable by a UML process, since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR. STACK_TOP is now TASK_SIZE minus the two stub pages. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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__ diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h index b54bd35..5b67d7c 100644 --- a/arch/um/include/common-offsets.h +++ b/arch/um/include/common-offsets.h @@ -39,3 +39,6 @@ DEFINE(UM_HZ, HZ); DEFINE(UM_USEC_PER_SEC, USEC_PER_SEC); DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC); DEFINE(UM_NSEC_PER_USEC, NSEC_PER_USEC); + +/* See as-layout.h for an explanation of the "- 1". Bah. */ +DEFINE(UM_TASK_SIZE, TASK_SIZE - 1); diff --git a/arch/um/include/mem_user.h b/arch/um/include/mem_user.h index a54514d..4e6707b 100644 --- a/arch/um/include/mem_user.h +++ b/arch/um/include/mem_user.h @@ -46,9 +46,6 @@ extern int iomem_size; #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1)) -extern unsigned long host_task_size; -extern unsigned long task_size; - extern int init_mem_user(void); extern void setup_memory(void *entry); extern unsigned long find_iomem(char *driver, unsigned long *len_out); @@ -62,6 +59,5 @@ extern unsigned long phys_offset(unsigned long phys); extern void unmap_physmem(void); extern void map_memory(unsigned long virt, unsigned long phys, unsigned long len, int r, int w, int x); -extern unsigned long get_kmem_end(void); #endif diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index 8196450..bf66b5b 100644 --- a/arch/um/kernel/exec.c +++ b/arch/um/kernel/exec.c @@ -19,7 +19,7 @@ void flush_thread(void) { void *data = NULL; - unsigned long end = proc_mm ? task_size : STUB_START; + unsigned long end = proc_mm ? TASK_SIZE : STUB_START; int ret; arch_flush_thread(¤t->thread.arch); diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c index f0ced98..187a756 100644 --- a/arch/um/kernel/ksyms.c +++ b/arch/um/kernel/ksyms.c @@ -18,11 +18,8 @@ EXPORT_SYMBOL(set_signals); EXPORT_SYMBOL(get_signals); EXPORT_SYMBOL(kernel_thread); EXPORT_SYMBOL(sys_waitpid); -EXPORT_SYMBOL(task_size); EXPORT_SYMBOL(flush_tlb_range); -EXPORT_SYMBOL(host_task_size); EXPORT_SYMBOL(arch_validate); -EXPORT_SYMBOL(get_kmem_end); EXPORT_SYMBOL(high_physmem); EXPORT_SYMBOL(empty_zero_page); diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c index e66432f..9c92900 100644 --- a/arch/um/kernel/physmem.c +++ b/arch/um/kernel/physmem.c @@ -55,16 +55,6 @@ int __init init_maps(unsigned long physmem, unsigned long iomem, return 0; } -/* Changed during early boot */ -static unsigned long kmem_top = 0; - -unsigned long get_kmem_end(void) -{ - if (kmem_top == 0) - kmem_top = host_task_size - 1024 * 1024; - return kmem_top; -} - void map_memory(unsigned long virt, unsigned long phys, unsigned long len, int r, int w, int x) { diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c index 96e0978..429fed2 100644 --- a/arch/um/kernel/tlb.c +++ b/arch/um/kernel/tlb.c @@ -511,7 +511,7 @@ void flush_tlb_mm(struct mm_struct *mm) if (atomic_read(&mm->mm_users) == 0) return; - end = proc_mm ? task_size : STUB_START; + end = proc_mm ? TASK_SIZE : STUB_START; fix_range(mm, 0, end, 0); } diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 1139e07..9ba39ab 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -101,8 +101,6 @@ const struct seq_operations cpuinfo_op = { }; /* Set in linux_main */ -unsigned long host_task_size; -unsigned long task_size; unsigned long uml_physmem; unsigned long uml_reserved; /* Also modified in mem_init */ unsigned long start_vm; @@ -234,20 +232,6 @@ EXPORT_SYMBOL(end_iomem); extern char __binary_start; -static unsigned long set_task_sizes_skas(unsigned long *task_size_out) -{ - /* Round up to the nearest 4M */ - unsigned long host_task_size = ROUND_4M((unsigned long) - &host_task_size); - - if (!skas_needs_stub) - *task_size_out = host_task_size; - else - *task_size_out = STUB_START & PGDIR_MASK; - - return host_task_size; -} - int __init linux_main(int argc, char **argv) { unsigned long avail, diff; @@ -278,8 +262,6 @@ int __init linux_main(int argc, char **argv) printf("UML running in %s mode\n", mode); - host_task_size = set_task_sizes_skas(&task_size); - brk_start = (unsigned long) sbrk(0); /* @@ -304,7 +286,7 @@ int __init linux_main(int argc, char **argv) highmem = 0; iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK; - max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC; + max_physmem = CONFIG_TOP_ADDR - uml_physmem - iomem_size - MIN_VMALLOC; /* * Zones have to begin on a 1 << MAX_ORDER page boundary, @@ -336,7 +318,7 @@ int __init linux_main(int argc, char **argv) } virtmem_size = physmem_size; - avail = get_kmem_end() - start_vm; + avail = CONFIG_TOP_ADDR - start_vm; if (physmem_size > avail) virtmem_size = avail; end_vm = start_vm + virtmem_size; diff --git a/include/asm-um/a.out.h b/include/asm-um/a.out.h index 9281dd8..f42ff145 100644 --- a/include/asm-um/a.out.h +++ b/include/asm-um/a.out.h @@ -13,11 +13,9 @@ extern unsigned long stacksizelim; -extern unsigned long host_task_size; - #define STACK_ROOM (stacksizelim) -#define STACK_TOP task_size +#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE) #define STACK_TOP_MAX STACK_TOP diff --git a/include/asm-um/fixmap.h b/include/asm-um/fixmap.h index 3d3e85d..89a87c1 100644 --- a/include/asm-um/fixmap.h +++ b/include/asm-um/fixmap.h @@ -56,9 +56,8 @@ extern void __set_fixmap (enum fixed_addresses idx, * the start of the fixmap, and leave one page empty * at the top of mem.. */ -extern unsigned long get_kmem_end(void); -#define FIXADDR_TOP (get_kmem_end() - 0x2000) +#define FIXADDR_TOP (CONFIG_TOP_ADDR - 2 * PAGE_SIZE) #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) diff --git a/include/asm-um/processor-generic.h b/include/asm-um/processor-generic.h index 35ab6a2..ecf6706 100644 --- a/include/asm-um/processor-generic.h +++ b/include/asm-um/processor-generic.h @@ -94,9 +94,7 @@ static inline void mm_copy_segments(struct mm_struct *from_mm, /* * User space process size: 3GB (default). */ -extern unsigned long task_size; - -#define TASK_SIZE (task_size) +#define TASK_SIZE (CONFIG_TOP_ADDR & PGDIR_MASK) /* This decides where the kernel will search for a free chunk of vm * space during mmap's.