diff options
author | Jeff Dike <jdike@addtoit.com> | 2008-02-08 07:22:07 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-08 12:22:42 -0500 |
commit | 536788fe2d28e11db6aeda74207d95d750fb761f (patch) | |
tree | 73df2d3a46c542c71d3a84c20c8fd1ce617386a3 /arch | |
parent | 2f569afd9ced9ebec9a6eb3dbf6f83429be0a7b4 (diff) |
uml: runtime host VMSPLIT detection
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is
needed on i386 if UML is to run on hosts with varying VMSPLITs without
recompilation.
TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of
an include of pgtable.h from processor.h, which can cause include loops.
On i386, task_size is calculated early in boot by probing the address space in
a binary search to figure out where the boundary between usable and non-usable
memory is. This tries to make sure that a page that is considered to be in
userspace is, or can be made, read-write. I'm concerned about a system-global
VDSO page in kernel memory being hit and considered to be a userspace page.
On x86_64, task_size is just the old value of CONFIG_TOP_ADDR.
A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced
by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it
irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in
arch/um/Makefile are also gone.
I noticed and fixed a missing extern in os.h when adding os_get_task_size.
Note: This has been revised to fix the 32-bit UML on 64-bit host bug that
Miklos ran into.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/um/Kconfig | 11 | ||||
-rw-r--r-- | arch/um/Kconfig.i386 | 37 | ||||
-rw-r--r-- | arch/um/Kconfig.x86_64 | 4 | ||||
-rw-r--r-- | arch/um/Makefile | 11 | ||||
-rw-r--r-- | arch/um/defconfig | 3 | ||||
-rw-r--r-- | arch/um/include/as-layout.h | 2 | ||||
-rw-r--r-- | arch/um/include/os.h | 5 | ||||
-rw-r--r-- | arch/um/kernel/exec.c | 2 | ||||
-rw-r--r-- | arch/um/kernel/um_arch.c | 16 | ||||
-rw-r--r-- | arch/um/os-Linux/sys-i386/Makefile | 2 | ||||
-rw-r--r-- | arch/um/os-Linux/sys-i386/task_size.c | 120 | ||||
-rw-r--r-- | arch/um/os-Linux/sys-x86_64/Makefile | 2 | ||||
-rw-r--r-- | arch/um/os-Linux/sys-x86_64/task_size.c | 5 |
13 files changed, 148 insertions, 72 deletions
diff --git a/arch/um/Kconfig b/arch/um/Kconfig index 99e51d059a02..dba8e05f0287 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig | |||
@@ -203,17 +203,6 @@ config NR_CPUS | |||
203 | depends on SMP | 203 | depends on SMP |
204 | default "32" | 204 | default "32" |
205 | 205 | ||
206 | config NEST_LEVEL | ||
207 | int "Nesting level" | ||
208 | default "0" | ||
209 | help | ||
210 | This is set to the number of layers of UMLs that this UML will be run | ||
211 | in. Normally, this is zero, meaning that it will run directly on the | ||
212 | host. Setting it to one will build a UML that can run inside a UML | ||
213 | that is running on the host. Generally, if you intend this UML to run | ||
214 | inside another UML, set CONFIG_NEST_LEVEL to one more than the host | ||
215 | UML. | ||
216 | |||
217 | config HIGHMEM | 206 | config HIGHMEM |
218 | bool "Highmem support (EXPERIMENTAL)" | 207 | bool "Highmem support (EXPERIMENTAL)" |
219 | depends on !64BIT && EXPERIMENTAL | 208 | depends on !64BIT && EXPERIMENTAL |
diff --git a/arch/um/Kconfig.i386 b/arch/um/Kconfig.i386 index e75264603d24..3cd8a04d66d8 100644 --- a/arch/um/Kconfig.i386 +++ b/arch/um/Kconfig.i386 | |||
@@ -23,43 +23,6 @@ config SEMAPHORE_SLEEPERS | |||
23 | bool | 23 | bool |
24 | default y | 24 | default y |
25 | 25 | ||
26 | choice | ||
27 | prompt "Host memory split" | ||
28 | default HOST_VMSPLIT_3G | ||
29 | help | ||
30 | This is needed when the host kernel on which you run has a non-default | ||
31 | (like 2G/2G) memory split, instead of the customary 3G/1G. If you did | ||
32 | not recompile your own kernel but use the default distro's one, you can | ||
33 | safely accept the "Default split" option. | ||
34 | |||
35 | It can be enabled on recent (>=2.6.16-rc2) vanilla kernels via | ||
36 | CONFIG_VM_SPLIT_*, or on previous kernels with special patches (-ck | ||
37 | patchset by Con Kolivas, or other ones) - option names match closely the | ||
38 | host CONFIG_VM_SPLIT_* ones. | ||
39 | |||
40 | A lower setting (where 1G/3G is lowest and 3G/1G is higher) will | ||
41 | tolerate even more "normal" host kernels, but an higher setting will be | ||
42 | stricter. | ||
43 | |||
44 | So, if you do not know what to do here, say 'Default split'. | ||
45 | |||
46 | config HOST_VMSPLIT_3G | ||
47 | bool "Default split (3G/1G user/kernel host split)" | ||
48 | config HOST_VMSPLIT_3G_OPT | ||
49 | bool "3G/1G user/kernel host split (for full 1G low memory)" | ||
50 | config HOST_VMSPLIT_2G | ||
51 | bool "2G/2G user/kernel host split" | ||
52 | config HOST_VMSPLIT_1G | ||
53 | bool "1G/3G user/kernel host split" | ||
54 | endchoice | ||
55 | |||
56 | config TOP_ADDR | ||
57 | hex | ||
58 | default 0xB0000000 if HOST_VMSPLIT_3G_OPT | ||
59 | default 0x78000000 if HOST_VMSPLIT_2G | ||
60 | default 0x40000000 if HOST_VMSPLIT_1G | ||
61 | default 0xC0000000 | ||
62 | |||
63 | config 3_LEVEL_PGTABLES | 26 | config 3_LEVEL_PGTABLES |
64 | bool "Three-level pagetables (EXPERIMENTAL)" | 27 | bool "Three-level pagetables (EXPERIMENTAL)" |
65 | default n | 28 | default n |
diff --git a/arch/um/Kconfig.x86_64 b/arch/um/Kconfig.x86_64 index b438f0e14271..6533b349f061 100644 --- a/arch/um/Kconfig.x86_64 +++ b/arch/um/Kconfig.x86_64 | |||
@@ -15,10 +15,6 @@ config SEMAPHORE_SLEEPERS | |||
15 | bool | 15 | bool |
16 | default y | 16 | default y |
17 | 17 | ||
18 | config TOP_ADDR | ||
19 | hex | ||
20 | default 0x7fc0000000 | ||
21 | |||
22 | config 3_LEVEL_PGTABLES | 18 | config 3_LEVEL_PGTABLES |
23 | bool | 19 | bool |
24 | default y | 20 | default y |
diff --git a/arch/um/Makefile b/arch/um/Makefile index cb4af9bf2074..dbeab15e7bb7 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile | |||
@@ -79,13 +79,6 @@ KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \ | |||
79 | KBUILD_CFLAGS += $(KERNEL_DEFINES) | 79 | KBUILD_CFLAGS += $(KERNEL_DEFINES) |
80 | KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,) | 80 | KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,) |
81 | 81 | ||
82 | # These are needed for clean and mrproper, since in that case .config is not | ||
83 | # included; the values here are meaningless | ||
84 | |||
85 | CONFIG_NEST_LEVEL ?= 0 | ||
86 | |||
87 | SIZE = ($(CONFIG_NEST_LEVEL) * 0x20000000) | ||
88 | |||
89 | PHONY += linux | 82 | PHONY += linux |
90 | 83 | ||
91 | all: linux | 84 | all: linux |
@@ -120,10 +113,6 @@ CFLAGS_NO_HARDENING := $(call cc-option, -fno-PIC,) $(call cc-option, -fno-pic,) | |||
120 | CONFIG_KERNEL_STACK_ORDER ?= 2 | 113 | CONFIG_KERNEL_STACK_ORDER ?= 2 |
121 | STACK_SIZE := $(shell echo $$[ 4096 * (1 << $(CONFIG_KERNEL_STACK_ORDER)) ] ) | 114 | STACK_SIZE := $(shell echo $$[ 4096 * (1 << $(CONFIG_KERNEL_STACK_ORDER)) ] ) |
122 | 115 | ||
123 | ifndef START | ||
124 | START = $(shell echo $$[ $(TOP_ADDR) - $(SIZE) ] ) | ||
125 | endif | ||
126 | |||
127 | CPPFLAGS_vmlinux.lds = -U$(SUBARCH) -DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \ | 116 | CPPFLAGS_vmlinux.lds = -U$(SUBARCH) -DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \ |
128 | -DELF_FORMAT="$(ELF_FORMAT)" -DKERNEL_STACK_SIZE=$(STACK_SIZE) | 117 | -DELF_FORMAT="$(ELF_FORMAT)" -DKERNEL_STACK_SIZE=$(STACK_SIZE) |
129 | 118 | ||
diff --git a/arch/um/defconfig b/arch/um/defconfig index 86db2862f222..59215bc264ef 100644 --- a/arch/um/defconfig +++ b/arch/um/defconfig | |||
@@ -56,8 +56,6 @@ CONFIG_X86_TSC=y | |||
56 | CONFIG_UML_X86=y | 56 | CONFIG_UML_X86=y |
57 | # CONFIG_64BIT is not set | 57 | # CONFIG_64BIT is not set |
58 | CONFIG_SEMAPHORE_SLEEPERS=y | 58 | CONFIG_SEMAPHORE_SLEEPERS=y |
59 | # CONFIG_HOST_2G_2G is not set | ||
60 | CONFIG_TOP_ADDR=0xc0000000 | ||
61 | # CONFIG_3_LEVEL_PGTABLES is not set | 59 | # CONFIG_3_LEVEL_PGTABLES is not set |
62 | CONFIG_ARCH_HAS_SC_SIGNALS=y | 60 | CONFIG_ARCH_HAS_SC_SIGNALS=y |
63 | CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA=y | 61 | CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA=y |
@@ -81,7 +79,6 @@ CONFIG_HOSTFS=y | |||
81 | # CONFIG_HPPFS is not set | 79 | # CONFIG_HPPFS is not set |
82 | CONFIG_MCONSOLE=y | 80 | CONFIG_MCONSOLE=y |
83 | CONFIG_MAGIC_SYSRQ=y | 81 | CONFIG_MAGIC_SYSRQ=y |
84 | CONFIG_NEST_LEVEL=0 | ||
85 | # CONFIG_HIGHMEM is not set | 82 | # CONFIG_HIGHMEM is not set |
86 | CONFIG_KERNEL_STACK_ORDER=0 | 83 | CONFIG_KERNEL_STACK_ORDER=0 |
87 | 84 | ||
diff --git a/arch/um/include/as-layout.h b/arch/um/include/as-layout.h index 606bb5c7fdf6..cac542d8ff70 100644 --- a/arch/um/include/as-layout.h +++ b/arch/um/include/as-layout.h | |||
@@ -57,6 +57,8 @@ extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end; | |||
57 | extern unsigned long _unprotected_end; | 57 | extern unsigned long _unprotected_end; |
58 | extern unsigned long brk_start; | 58 | extern unsigned long brk_start; |
59 | 59 | ||
60 | extern unsigned long host_task_size; | ||
61 | |||
60 | extern int linux_main(int argc, char **argv); | 62 | extern int linux_main(int argc, char **argv); |
61 | 63 | ||
62 | extern void (*sig_info[])(int, struct uml_pt_regs *); | 64 | extern void (*sig_info[])(int, struct uml_pt_regs *); |
diff --git a/arch/um/include/os.h b/arch/um/include/os.h index 0b6b62733303..32c799e3a495 100644 --- a/arch/um/include/os.h +++ b/arch/um/include/os.h | |||
@@ -295,6 +295,9 @@ extern void maybe_sigio_broken(int fd, int read); | |||
295 | extern int os_arch_prctl(int pid, int code, unsigned long *addr); | 295 | extern int os_arch_prctl(int pid, int code, unsigned long *addr); |
296 | 296 | ||
297 | /* tty.c */ | 297 | /* tty.c */ |
298 | int get_pty(void); | 298 | extern int get_pty(void); |
299 | |||
300 | /* sys-$ARCH/task_size.c */ | ||
301 | extern unsigned long os_get_task_size(void); | ||
299 | 302 | ||
300 | #endif | 303 | #endif |
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index 76a62c0cb2bc..f5d7f4569ba7 100644 --- a/arch/um/kernel/exec.c +++ b/arch/um/kernel/exec.c | |||
@@ -25,7 +25,7 @@ void flush_thread(void) | |||
25 | 25 | ||
26 | ret = unmap(¤t->mm->context.id, 0, STUB_START, 0, &data); | 26 | ret = unmap(¤t->mm->context.id, 0, STUB_START, 0, &data); |
27 | ret = ret || unmap(¤t->mm->context.id, STUB_END, | 27 | ret = ret || unmap(¤t->mm->context.id, STUB_END, |
28 | TASK_SIZE - STUB_END, 1, &data); | 28 | host_task_size - STUB_END, 1, &data); |
29 | if (ret) { | 29 | if (ret) { |
30 | printk(KERN_ERR "flush_thread - clearing address space failed, " | 30 | printk(KERN_ERR "flush_thread - clearing address space failed, " |
31 | "err = %d\n", ret); | 31 | "err = %d\n", ret); |
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 468aba990dbd..a6c1dd1cf5a1 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c | |||
@@ -241,6 +241,11 @@ static struct notifier_block panic_exit_notifier = { | |||
241 | }; | 241 | }; |
242 | 242 | ||
243 | /* Set during early boot */ | 243 | /* Set during early boot */ |
244 | unsigned long task_size; | ||
245 | EXPORT_SYMBOL(task_size); | ||
246 | |||
247 | unsigned long host_task_size; | ||
248 | |||
244 | unsigned long brk_start; | 249 | unsigned long brk_start; |
245 | unsigned long end_iomem; | 250 | unsigned long end_iomem; |
246 | EXPORT_SYMBOL(end_iomem); | 251 | EXPORT_SYMBOL(end_iomem); |
@@ -267,6 +272,13 @@ int __init linux_main(int argc, char **argv) | |||
267 | if (have_root == 0) | 272 | if (have_root == 0) |
268 | add_arg(DEFAULT_COMMAND_LINE); | 273 | add_arg(DEFAULT_COMMAND_LINE); |
269 | 274 | ||
275 | host_task_size = os_get_task_size(); | ||
276 | /* | ||
277 | * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps | ||
278 | * out | ||
279 | */ | ||
280 | task_size = host_task_size & PGDIR_MASK; | ||
281 | |||
270 | /* OS sanity checks that need to happen before the kernel runs */ | 282 | /* OS sanity checks that need to happen before the kernel runs */ |
271 | os_early_checks(); | 283 | os_early_checks(); |
272 | 284 | ||
@@ -303,7 +315,7 @@ int __init linux_main(int argc, char **argv) | |||
303 | 315 | ||
304 | highmem = 0; | 316 | highmem = 0; |
305 | iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK; | 317 | iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK; |
306 | max_physmem = CONFIG_TOP_ADDR - uml_physmem - iomem_size - MIN_VMALLOC; | 318 | max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC; |
307 | 319 | ||
308 | /* | 320 | /* |
309 | * Zones have to begin on a 1 << MAX_ORDER page boundary, | 321 | * Zones have to begin on a 1 << MAX_ORDER page boundary, |
@@ -335,7 +347,7 @@ int __init linux_main(int argc, char **argv) | |||
335 | } | 347 | } |
336 | 348 | ||
337 | virtmem_size = physmem_size; | 349 | virtmem_size = physmem_size; |
338 | avail = CONFIG_TOP_ADDR - start_vm; | 350 | avail = TASK_SIZE - start_vm; |
339 | if (physmem_size > avail) | 351 | if (physmem_size > avail) |
340 | virtmem_size = avail; | 352 | virtmem_size = avail; |
341 | end_vm = start_vm + virtmem_size; | 353 | end_vm = start_vm + virtmem_size; |
diff --git a/arch/um/os-Linux/sys-i386/Makefile b/arch/um/os-Linux/sys-i386/Makefile index a841262c594a..b4bc6ac4f30b 100644 --- a/arch/um/os-Linux/sys-i386/Makefile +++ b/arch/um/os-Linux/sys-i386/Makefile | |||
@@ -3,7 +3,7 @@ | |||
3 | # Licensed under the GPL | 3 | # Licensed under the GPL |
4 | # | 4 | # |
5 | 5 | ||
6 | obj-y = registers.o signal.o tls.o | 6 | obj-y = registers.o signal.o task_size.o tls.o |
7 | 7 | ||
8 | USER_OBJS := $(obj-y) | 8 | USER_OBJS := $(obj-y) |
9 | 9 | ||
diff --git a/arch/um/os-Linux/sys-i386/task_size.c b/arch/um/os-Linux/sys-i386/task_size.c new file mode 100644 index 000000000000..48d211b3d9a1 --- /dev/null +++ b/arch/um/os-Linux/sys-i386/task_size.c | |||
@@ -0,0 +1,120 @@ | |||
1 | #include <stdio.h> | ||
2 | #include <stdlib.h> | ||
3 | #include <signal.h> | ||
4 | #include <sys/mman.h> | ||
5 | #include "longjmp.h" | ||
6 | #include "kern_constants.h" | ||
7 | |||
8 | static jmp_buf buf; | ||
9 | |||
10 | static void segfault(int sig) | ||
11 | { | ||
12 | longjmp(buf, 1); | ||
13 | } | ||
14 | |||
15 | static int page_ok(unsigned long page) | ||
16 | { | ||
17 | unsigned long *address = (unsigned long *) (page << UM_KERN_PAGE_SHIFT); | ||
18 | unsigned long n = ~0UL; | ||
19 | void *mapped = NULL; | ||
20 | int ok = 0; | ||
21 | |||
22 | /* | ||
23 | * First see if the page is readable. If it is, it may still | ||
24 | * be a VDSO, so we go on to see if it's writable. If not | ||
25 | * then try mapping memory there. If that fails, then we're | ||
26 | * still in the kernel area. As a sanity check, we'll fail if | ||
27 | * the mmap succeeds, but gives us an address different from | ||
28 | * what we wanted. | ||
29 | */ | ||
30 | if (setjmp(buf) == 0) | ||
31 | n = *address; | ||
32 | else { | ||
33 | mapped = mmap(address, UM_KERN_PAGE_SIZE, | ||
34 | PROT_READ | PROT_WRITE, | ||
35 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | ||
36 | if (mapped == MAP_FAILED) | ||
37 | return 0; | ||
38 | if (mapped != address) | ||
39 | goto out; | ||
40 | } | ||
41 | |||
42 | /* | ||
43 | * Now, is it writeable? If so, then we're in user address | ||
44 | * space. If not, then try mprotecting it and try the write | ||
45 | * again. | ||
46 | */ | ||
47 | if (setjmp(buf) == 0) { | ||
48 | *address = n; | ||
49 | ok = 1; | ||
50 | goto out; | ||
51 | } else if (mprotect(address, UM_KERN_PAGE_SIZE, | ||
52 | PROT_READ | PROT_WRITE) != 0) | ||
53 | goto out; | ||
54 | |||
55 | if (setjmp(buf) == 0) { | ||
56 | *address = n; | ||
57 | ok = 1; | ||
58 | } | ||
59 | |||
60 | out: | ||
61 | if (mapped != NULL) | ||
62 | munmap(mapped, UM_KERN_PAGE_SIZE); | ||
63 | return ok; | ||
64 | } | ||
65 | |||
66 | unsigned long os_get_task_size(void) | ||
67 | { | ||
68 | struct sigaction sa, old; | ||
69 | unsigned long bottom = 0; | ||
70 | /* | ||
71 | * A 32-bit UML on a 64-bit host gets confused about the VDSO at | ||
72 | * 0xffffe000. It is mapped, is readable, can be reprotected writeable | ||
73 | * and written. However, exec discovers later that it can't be | ||
74 | * unmapped. So, just set the highest address to be checked to just | ||
75 | * below it. This might waste some address space on 4G/4G 32-bit | ||
76 | * hosts, but shouldn't hurt otherwise. | ||
77 | */ | ||
78 | unsigned long top = 0xffffd000 >> UM_KERN_PAGE_SHIFT; | ||
79 | unsigned long test; | ||
80 | |||
81 | printf("Locating the top of the address space ... "); | ||
82 | fflush(stdout); | ||
83 | |||
84 | /* | ||
85 | * We're going to be longjmping out of the signal handler, so | ||
86 | * SA_DEFER needs to be set. | ||
87 | */ | ||
88 | sa.sa_handler = segfault; | ||
89 | sigemptyset(&sa.sa_mask); | ||
90 | sa.sa_flags = SA_NODEFER; | ||
91 | sigaction(SIGSEGV, &sa, &old); | ||
92 | |||
93 | if (!page_ok(bottom)) { | ||
94 | fprintf(stderr, "Address 0x%x no good?\n", | ||
95 | bottom << UM_KERN_PAGE_SHIFT); | ||
96 | exit(1); | ||
97 | } | ||
98 | |||
99 | /* This could happen with a 4G/4G split */ | ||
100 | if (page_ok(top)) | ||
101 | goto out; | ||
102 | |||
103 | do { | ||
104 | test = bottom + (top - bottom) / 2; | ||
105 | if (page_ok(test)) | ||
106 | bottom = test; | ||
107 | else | ||
108 | top = test; | ||
109 | } while (top - bottom > 1); | ||
110 | |||
111 | out: | ||
112 | /* Restore the old SIGSEGV handling */ | ||
113 | sigaction(SIGSEGV, &old, NULL); | ||
114 | |||
115 | top <<= UM_KERN_PAGE_SHIFT; | ||
116 | printf("0x%x\n", top); | ||
117 | fflush(stdout); | ||
118 | |||
119 | return top; | ||
120 | } | ||
diff --git a/arch/um/os-Linux/sys-x86_64/Makefile b/arch/um/os-Linux/sys-x86_64/Makefile index a42a4ef02e1e..a44a47f8f57b 100644 --- a/arch/um/os-Linux/sys-x86_64/Makefile +++ b/arch/um/os-Linux/sys-x86_64/Makefile | |||
@@ -3,7 +3,7 @@ | |||
3 | # Licensed under the GPL | 3 | # Licensed under the GPL |
4 | # | 4 | # |
5 | 5 | ||
6 | obj-y = registers.o prctl.o signal.o | 6 | obj-y = registers.o prctl.o signal.o task_size.o |
7 | 7 | ||
8 | USER_OBJS := $(obj-y) | 8 | USER_OBJS := $(obj-y) |
9 | 9 | ||
diff --git a/arch/um/os-Linux/sys-x86_64/task_size.c b/arch/um/os-Linux/sys-x86_64/task_size.c new file mode 100644 index 000000000000..fad6f57f8ee3 --- /dev/null +++ b/arch/um/os-Linux/sys-x86_64/task_size.c | |||
@@ -0,0 +1,5 @@ | |||
1 | unsigned long os_get_task_size(unsigned long shift) | ||
2 | { | ||
3 | /* The old value of CONFIG_TOP_ADDR */ | ||
4 | return 0x7fc0000000; | ||
5 | } | ||