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uml: fix stub address calculations 

The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.

I'd rather not duplicate the four known host vmsplit cases for each of these
symbols.  I'd also like to calculate them based on the highest userspace
address.

The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h.  CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone.  In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.

i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently.  However, they are also used in stub.S, where C types don't work
so well.  So, there are ASM_ versions of these constants for use in stub.S.  I
also ifdef-ed the non-asm-friendly portion of as-layout.h.

With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.

defconfig has the old symbols deleted.

I also print these addresses out in case there is any problem mapping them on
the host.

The two stub.S files had some trailing whitespace, so that is cleaned up here.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Dike 2007-10-16 01:27:33 -07:00 committed by Linus Torvalds
parent 605c1e5769
commit 54ae36f24b
18 changed files with 81 additions and 77 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
arch/um/Kconfig.i386
View File

@ -65,20 +65,6 @@ config 3_LEVEL_PGTABLES
However, this it experimental on 32-bit architectures, so if unsure say
N (on x86-64 it's automatically enabled, instead, as it's safe there).
config STUB_CODE
hex
default 0xbfffe000 if !HOST_VMSPLIT_2G
default 0x7fffe000 if HOST_VMSPLIT_2G
config STUB_DATA
hex
default 0xbffff000 if !HOST_VMSPLIT_2G
default 0x7ffff000 if HOST_VMSPLIT_2G
config STUB_START
hex
default STUB_CODE
config ARCH_HAS_SC_SIGNALS
bool
default y

14
arch/um/Kconfig.x86_64
View File

@ -17,24 +17,12 @@ config SEMAPHORE_SLEEPERS
config TOP_ADDR
hex
default 0x80000000
default 0x7fc0000000
config 3_LEVEL_PGTABLES
bool
default y
config STUB_CODE
hex
default 0x7fbfffe000
config STUB_DATA
hex
default 0x7fbffff000
config STUB_START
hex
default STUB_CODE
config ARCH_HAS_SC_SIGNALS
bool
default n

3
arch/um/defconfig
View File

@ -59,9 +59,6 @@ CONFIG_SEMAPHORE_SLEEPERS=y
# CONFIG_HOST_2G_2G is not set
CONFIG_TOP_ADDR=0xc0000000
# CONFIG_3_LEVEL_PGTABLES is not set
CONFIG_STUB_CODE=0xbfffe000
CONFIG_STUB_DATA=0xbffff000
CONFIG_STUB_START=0xbfffe000
CONFIG_ARCH_HAS_SC_SIGNALS=y
CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA=y
CONFIG_GENERIC_HWEIGHT=y

24
arch/um/include/as-layout.h
View File

@ -6,6 +6,28 @@
#ifndef __START_H__
#define __START_H__
#include "uml-config.h"
#include "kern_constants.h"
/*
* Assembly doesn't want any casting, but C does, so define these
* without casts here, and define new symbols with casts inside the C
* section.
*/
#define ASM_STUB_CODE (UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
#define ASM_STUB_DATA (UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
#define ASM_STUB_START ASM_STUB_CODE
/*
* This file is included by the assembly stubs, which just want the
* definitions above.
*/
#ifndef __ASSEMBLY__
#define STUB_CODE ((unsigned long) ASM_STUB_CODE)
#define STUB_DATA ((unsigned long) ASM_STUB_DATA)
#define STUB_START ((unsigned long) ASM_STUB_START)
#include "sysdep/ptrace.h"
struct cpu_task {
@ -32,3 +54,5 @@ extern int linux_main(int argc, char **argv);
extern void (*sig_info[])(int, struct uml_pt_regs *);
#endif
#endif

11
arch/um/include/sysdep-i386/stub.h
View File

@ -9,6 +9,7 @@
#include <sys/mman.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>
#include "as-layout.h"
#include "stub-data.h"
#include "kern_constants.h"
#include "uml-config.h"
@ -89,12 +90,12 @@ static inline void remap_stack(int fd, unsigned long offset)
{
__asm__ volatile ("movl %%eax,%%ebp ; movl %0,%%eax ; int $0x80 ;"
"movl %7, %%ebx ; movl %%eax, (%%ebx)"
: : "g" (STUB_MMAP_NR), "b" (UML_CONFIG_STUB_DATA),
"c" (UM_KERN_PAGE_SIZE),
: : "g" (STUB_MMAP_NR), "b" (STUB_DATA),
"c" (UM_KERN_PAGE_SIZE),
"d" (PROT_READ | PROT_WRITE),
"S" (MAP_FIXED | MAP_SHARED), "D" (fd),
"a" (offset),
"i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
"S" (MAP_FIXED | MAP_SHARED), "D" (fd),
"a" (offset),
"i" (&((struct stub_data *) STUB_DATA)->err)
: "memory");
}

13
arch/um/include/sysdep-x86_64/stub.h
View File

@ -9,6 +9,7 @@
#include <sys/mman.h>
#include <asm/unistd.h>
#include <sysdep/ptrace_user.h>
#include "as-layout.h"
#include "stub-data.h"
#include "kern_constants.h"
#include "uml-config.h"
@ -94,13 +95,13 @@ static inline void remap_stack(long fd, unsigned long offset)
{
__asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
"movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
"movq %%rax, (%%rbx)":
: "a" (STUB_MMAP_NR), "D" (UML_CONFIG_STUB_DATA),
"S" (UM_KERN_PAGE_SIZE),
"d" (PROT_READ | PROT_WRITE),
"g" (MAP_FIXED | MAP_SHARED), "g" (fd),
"movq %%rax, (%%rbx)":
: "a" (STUB_MMAP_NR), "D" (STUB_DATA),
"S" (UM_KERN_PAGE_SIZE),
"d" (PROT_READ | PROT_WRITE),
"g" (MAP_FIXED | MAP_SHARED), "g" (fd),
"g" (offset),
"i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
"i" (&((struct stub_data *) STUB_DATA)->err)
: __syscall_clobber, "r10", "r8", "r9" );
}

3
arch/um/kernel/exec.c
View File

@ -11,6 +11,7 @@
#include "asm/current.h"
#include "asm/processor.h"
#include "asm/uaccess.h"
#include "as-layout.h"
#include "mem_user.h"
#include "skas.h"
#include "os.h"
@ -18,7 +19,7 @@
void flush_thread(void)
{
void *data = NULL;
unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
unsigned long end = proc_mm ? task_size : STUB_START;
int ret;
arch_flush_thread(&current->thread.arch);

6
arch/um/kernel/skas/clone.c
View File

@ -4,6 +4,7 @@
#include <sys/time.h>
#include <asm/unistd.h>
#include <asm/page.h>
#include "as-layout.h"
#include "ptrace_user.h"
#include "skas.h"
#include "stub-data.h"
@ -21,12 +22,11 @@
void __attribute__ ((__section__ (".__syscall_stub")))
stub_clone_handler(void)
{
struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
struct stub_data *data = (struct stub_data *) STUB_DATA;
long err;
err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE / 2 -
sizeof(void *));
STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
if(err != 0)
goto out;

5
arch/um/kernel/skas/mmu.c
View File

@ -7,6 +7,7 @@
#include "linux/sched.h"
#include "asm/pgalloc.h"
#include "asm/pgtable.h"
#include "as-layout.h"
#include "os.h"
#include "skas.h"
@ -83,12 +84,12 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
*/
mm->pgd[USER_PTRS_PER_PGD] = __pgd(0);
ret = init_stub_pte(mm, CONFIG_STUB_CODE,
ret = init_stub_pte(mm, STUB_CODE,
(unsigned long) &__syscall_stub_start);
if (ret)
goto out_free;
ret = init_stub_pte(mm, CONFIG_STUB_DATA, stack);
ret = init_stub_pte(mm, STUB_DATA, stack);
if (ret)
goto out_free;

2
arch/um/kernel/skas/process.c
View File

@ -18,7 +18,7 @@ int new_mm(unsigned long stack)
return fd;
if (skas_needs_stub)
map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
return fd;
}

6
arch/um/kernel/tlb.c
View File

@ -485,8 +485,8 @@ void __flush_tlb_one(unsigned long addr)
static void fix_range(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force)
{
if (!proc_mm && (end_addr > CONFIG_STUB_START))
end_addr = CONFIG_STUB_START;
if (!proc_mm && (end_addr > STUB_START))
end_addr = STUB_START;
fix_range_common(mm, start_addr, end_addr, force);
}
@ -510,7 +510,7 @@ void flush_tlb_mm(struct mm_struct *mm)
if (atomic_read(&mm->mm_users) == 0)
return;
end = proc_mm ? task_size : CONFIG_STUB_START;
end = proc_mm ? task_size : STUB_START;
fix_range(mm, 0, end, 0);
}

3
arch/um/kernel/um_arch.c
View File

@ -242,7 +242,8 @@ static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
if (!skas_needs_stub)
*task_size_out = host_task_size;
else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
else
*task_size_out = STUB_START & PGDIR_MASK;
return host_task_size;
}

8
arch/um/os-Linux/skas/mem.c
View File

@ -10,6 +10,7 @@
#include <sys/mman.h>
#include "init.h"
#include "kern_constants.h"
#include "as-layout.h"
#include "mm_id.h"
#include "os.h"
#include "proc_mm.h"
@ -40,7 +41,7 @@ static unsigned long syscall_regs[MAX_REG_NR];
static int __init init_syscall_regs(void)
{
get_safe_registers(syscall_regs);
syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
syscall_regs[REGS_IP_INDEX] = STUB_CODE +
((unsigned long) &batch_syscall_stub -
(unsigned long) &__syscall_stub_start);
return 0;
@ -93,8 +94,7 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
ret = *((unsigned long *) mm_idp->stack);
offset = *((unsigned long *) mm_idp->stack + 1);
if (offset) {
data = (unsigned long *)(mm_idp->stack +
offset - UML_CONFIG_STUB_DATA);
data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
"data = %p\n", ret, offset, data);
syscall = (unsigned long *)((unsigned long)data + data[0]);
@ -182,7 +182,7 @@ long syscall_stub_data(struct mm_id * mm_idp,
memcpy(stack + 1, data, data_count * sizeof(long));
*stub_addr = (void *)(((unsigned long)(stack + 1) &
~UM_KERN_PAGE_MASK) + UML_CONFIG_STUB_DATA);
~UM_KERN_PAGE_MASK) + STUB_DATA);
return 0;
}

21
arch/um/os-Linux/skas/process.c
View File

@ -191,22 +191,23 @@ static int userspace_tramp(void *stack)
int fd;
unsigned long long offset;
fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
addr = mmap64((void *) UML_CONFIG_STUB_CODE, UM_KERN_PAGE_SIZE,
addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
if (addr == MAP_FAILED) {
printk(UM_KERN_ERR "mapping mmap stub failed, "
"errno = %d\n", errno);
printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, "
"errno = %d\n", STUB_CODE, errno);
exit(1);
}
if (stack != NULL) {
fd = phys_mapping(to_phys(stack), &offset);
addr = mmap((void *) UML_CONFIG_STUB_DATA,
addr = mmap((void *) STUB_DATA,
UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_FIXED | MAP_SHARED, fd, offset);
if (addr == MAP_FAILED) {
printk(UM_KERN_ERR "mapping segfault stack "
"failed, errno = %d\n", errno);
"at 0x%lx failed, errno = %d\n",
STUB_DATA, errno);
exit(1);
}
}
@ -214,11 +215,11 @@ static int userspace_tramp(void *stack)
if (!ptrace_faultinfo && (stack != NULL)) {
struct sigaction sa;
unsigned long v = UML_CONFIG_STUB_CODE +
unsigned long v = STUB_CODE +
(unsigned long) stub_segv_handler -
(unsigned long) &__syscall_stub_start;
set_sigstack((void *) UML_CONFIG_STUB_DATA, UM_KERN_PAGE_SIZE);
set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE);
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sigaddset(&sa.sa_mask, SIGWINCH);
@ -382,10 +383,10 @@ static int __init init_thread_regs(void)
{
get_safe_registers(thread_regs);
/* Set parent's instruction pointer to start of clone-stub */
thread_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
thread_regs[REGS_IP_INDEX] = STUB_CODE +
(unsigned long) stub_clone_handler -
(unsigned long) &__syscall_stub_start;
thread_regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE -
thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE -
sizeof(void *);
#ifdef __SIGNAL_FRAMESIZE
thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
@ -443,7 +444,7 @@ int copy_context_skas0(unsigned long new_stack, int pid)
* child's stack and check it.
*/
wait_stub_done(pid);
if (child_data->err != UML_CONFIG_STUB_DATA)
if (child_data->err != STUB_DATA)
panic("copy_context_skas0 - stub-child reports error %ld\n",
child_data->err);

9
arch/um/sys-i386/stub.S
View File

@ -1,4 +1,5 @@
#include "uml-config.h"
#include "as-layout.h"
.globl syscall_stub
.section .__syscall_stub, "x"
@ -6,7 +7,7 @@
.globl batch_syscall_stub
batch_syscall_stub:
/* load pointer to first operation */
mov $(UML_CONFIG_STUB_DATA+8), %esp
mov $(ASM_STUB_DATA+8), %esp
again:
/* load length of additional data */
@ -14,12 +15,12 @@ again:
/* if(length == 0) : end of list */
/* write possible 0 to header */
mov %eax, UML_CONFIG_STUB_DATA+4
mov %eax, ASM_STUB_DATA+4
cmpl $0, %eax
jz done
/* save current pointer */
mov %esp, UML_CONFIG_STUB_DATA+4
mov %esp, ASM_STUB_DATA+4
/* skip additional data */
add %eax, %esp
@ -45,7 +46,7 @@ again:
done:
/* save return value */
mov %eax, UML_CONFIG_STUB_DATA
mov %eax, ASM_STUB_DATA
/* stop */
int3

4
arch/um/sys-i386/stub_segv.c
View File

@ -6,6 +6,7 @@
#include <signal.h>
#include <sys/select.h> /* The only way I can see to get sigset_t */
#include <asm/unistd.h>
#include "as-layout.h"
#include "uml-config.h"
#include "sysdep/stub.h"
#include "sysdep/sigcontext.h"
@ -17,8 +18,7 @@ stub_segv_handler(int sig)
struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
int pid;
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
sc);
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), sc);
pid = stub_syscall0(__NR_getpid);
stub_syscall2(__NR_kill, pid, SIGUSR1);

9
arch/um/sys-x86_64/stub.S
View File

@ -1,4 +1,5 @@
#include "uml-config.h"
#include "as-layout.h"
.globl syscall_stub
.section .__syscall_stub, "x"
@ -7,18 +8,18 @@ syscall_stub:
/* We don't have 64-bit constants, so this constructs the address
* we need.
*/
movq $(UML_CONFIG_STUB_DATA >> 32), %rbx
movq $(ASM_STUB_DATA >> 32), %rbx
salq $32, %rbx
movq $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx
movq $(ASM_STUB_DATA & 0xffffffff), %rcx
or %rcx, %rbx
movq %rax, (%rbx)
int3
.globl batch_syscall_stub
batch_syscall_stub:
mov $(UML_CONFIG_STUB_DATA >> 32), %rbx
mov $(ASM_STUB_DATA >> 32), %rbx
sal $32, %rbx
mov $(UML_CONFIG_STUB_DATA & 0xffffffff), %rax
mov $(ASM_STUB_DATA & 0xffffffff), %rax
or %rax, %rbx
/* load pointer to first operation */
mov %rbx, %rsp

3
arch/um/sys-x86_64/stub_segv.c
View File

@ -6,6 +6,7 @@
#include <stddef.h>
#include <signal.h>
#include <asm/unistd.h>
#include "as-layout.h"
#include "uml-config.h"
#include "sysdep/sigcontext.h"
#include "sysdep/faultinfo.h"
@ -33,7 +34,7 @@ stub_segv_handler(int sig)
int pid;
__asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA),
&uc->uc_mcontext);
pid = stub_syscall0(__NR_getpid);