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Diffstat (limited to 'arch/um/kernel/skas/process.c')
-rw-r--r--arch/um/kernel/skas/process.c216
1 files changed, 183 insertions, 33 deletions
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index 773cd2b..ba671da 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002- 2004 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
@@ -13,7 +13,9 @@
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/user.h>
+#include <sys/time.h>
#include <asm/unistd.h>
+#include <asm/types.h>
#include "user.h"
#include "ptrace_user.h"
#include "time_user.h"
@@ -21,13 +23,18 @@
#include "user_util.h"
#include "kern_util.h"
#include "skas.h"
+#include "stub-data.h"
+#include "mm_id.h"
#include "sysdep/sigcontext.h"
+#include "sysdep/stub.h"
#include "os.h"
#include "proc_mm.h"
#include "skas_ptrace.h"
#include "chan_user.h"
#include "signal_user.h"
#include "registers.h"
+#include "mem.h"
+#include "uml-config.h"
#include "process.h"
int is_skas_winch(int pid, int fd, void *data)
@@ -39,20 +46,55 @@ int is_skas_winch(int pid, int fd, void *data)
return(1);
}
-void get_skas_faultinfo(int pid, struct faultinfo * fi)
+void wait_stub_done(int pid, int sig, char * fname)
{
- int err;
-
- err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
- if(err)
- panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
- "errno = %d\n", errno);
+ int n, status, err;
+
+ do {
+ if ( sig != -1 ) {
+ err = ptrace(PTRACE_CONT, pid, 0, sig);
+ if(err)
+ panic("%s : continue failed, errno = %d\n",
+ fname, errno);
+ }
+ sig = 0;
+
+ CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
+ } while((n >= 0) && WIFSTOPPED(status) &&
+ (WSTOPSIG(status) == SIGVTALRM));
+
+ if((n < 0) || !WIFSTOPPED(status) ||
+ (WSTOPSIG(status) != SIGUSR1 && WSTOPSIG(status != SIGTRAP))){
+ panic("%s : failed to wait for SIGUSR1/SIGTRAP, "
+ "pid = %d, n = %d, errno = %d, status = 0x%x\n",
+ fname, pid, n, errno, status);
+ }
+}
- /* Special handling for i386, which has different structs */
- if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
- memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
- sizeof(struct faultinfo) -
- sizeof(struct ptrace_faultinfo));
+void get_skas_faultinfo(int pid, struct faultinfo * fi)
+{
+ int err;
+
+ if(ptrace_faultinfo){
+ err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
+ if(err)
+ panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
+ "errno = %d\n", errno);
+
+ /* Special handling for i386, which has different structs */
+ if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
+ memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
+ sizeof(struct faultinfo) -
+ sizeof(struct ptrace_faultinfo));
+ }
+ else {
+ wait_stub_done(pid, SIGSEGV, "get_skas_faultinfo");
+
+ /* faultinfo is prepared by the stub-segv-handler at start of
+ * the stub stack page. We just have to copy it.
+ */
+ memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
+ }
}
static void handle_segv(int pid, union uml_pt_regs * regs)
@@ -91,11 +133,56 @@ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu
handle_syscall(regs);
}
-static int userspace_tramp(void *arg)
+extern int __syscall_stub_start;
+
+static int userspace_tramp(void *stack)
{
- init_new_thread_signals(0);
- enable_timer();
+ void *addr;
+
ptrace(PTRACE_TRACEME, 0, 0, 0);
+
+ init_new_thread_signals(1);
+ enable_timer();
+
+ if(!proc_mm){
+ /* This has a pte, but it can't be mapped in with the usual
+ * tlb_flush mechanism because this is part of that mechanism
+ */
+ int fd;
+ __u64 offset;
+
+ fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
+ addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
+ PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ if(addr == MAP_FAILED){
+ printk("mapping mmap stub failed, errno = %d\n",
+ errno);
+ exit(1);
+ }
+
+ if(stack != NULL){
+ fd = phys_mapping(to_phys(stack), &offset);
+ addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
+ PROT_READ | PROT_WRITE,
+ MAP_FIXED | MAP_SHARED, fd, offset);
+ if(addr == MAP_FAILED){
+ printk("mapping segfault stack failed, "
+ "errno = %d\n", errno);
+ exit(1);
+ }
+ }
+ }
+ if(!ptrace_faultinfo && (stack != NULL)){
+ unsigned long v = UML_CONFIG_STUB_CODE +
+ (unsigned long) stub_segv_handler -
+ (unsigned long) &__syscall_stub_start;
+
+ set_sigstack((void *) UML_CONFIG_STUB_DATA, page_size());
+ set_handler(SIGSEGV, (void *) v, SA_ONSTACK,
+ SIGIO, SIGWINCH, SIGALRM, SIGVTALRM,
+ SIGUSR1, -1);
+ }
+
os_stop_process(os_getpid());
return(0);
}
@@ -105,11 +192,11 @@ static int userspace_tramp(void *arg)
#define NR_CPUS 1
int userspace_pid[NR_CPUS];
-void start_userspace(int cpu)
+int start_userspace(unsigned long stub_stack)
{
void *stack;
unsigned long sp;
- int pid, status, n;
+ int pid, status, n, flags;
stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
@@ -117,8 +204,9 @@ void start_userspace(int cpu)
panic("start_userspace : mmap failed, errno = %d", errno);
sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
- pid = clone(userspace_tramp, (void *) sp,
- CLONE_FILES | CLONE_VM | SIGCHLD, NULL);
+ flags = CLONE_FILES | SIGCHLD;
+ if(proc_mm) flags |= CLONE_VM;
+ pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
if(pid < 0)
panic("start_userspace : clone failed, errno = %d", errno);
@@ -140,7 +228,7 @@ void start_userspace(int cpu)
if(munmap(stack, PAGE_SIZE) < 0)
panic("start_userspace : munmap failed, errno = %d\n", errno);
- userspace_pid[cpu] = pid;
+ return(pid);
}
void userspace(union uml_pt_regs *regs)
@@ -174,7 +262,9 @@ void userspace(union uml_pt_regs *regs)
if(WIFSTOPPED(status)){
switch(WSTOPSIG(status)){
case SIGSEGV:
- handle_segv(pid, regs);
+ if(PTRACE_FULL_FAULTINFO || !ptrace_faultinfo)
+ user_signal(SIGSEGV, regs, pid);
+ else handle_segv(pid, regs);
break;
case SIGTRAP + 0x80:
handle_trap(pid, regs, local_using_sysemu);
@@ -194,6 +284,7 @@ void userspace(union uml_pt_regs *regs)
printk("userspace - child stopped with signal "
"%d\n", WSTOPSIG(status));
}
+ pid = userspace_pid[0];
interrupt_end();
/* Avoid -ERESTARTSYS handling in host */
@@ -207,6 +298,67 @@ void userspace(union uml_pt_regs *regs)
#define INIT_JMP_HALT 3
#define INIT_JMP_REBOOT 4
+
+int copy_context_skas0(unsigned long new_stack, int pid)
+{
+ int err;
+ unsigned long regs[MAX_REG_NR];
+ unsigned long current_stack = current_stub_stack();
+ struct stub_data *data = (struct stub_data *) current_stack;
+ struct stub_data *child_data = (struct stub_data *) new_stack;
+ __u64 new_offset;
+ int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset);
+
+ /* prepare offset and fd of child's stack as argument for parent's
+ * and child's mmap2 calls
+ */
+ *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset),
+ .fd = new_fd,
+ .timer = ((struct itimerval)
+ { { 0, 1000000 / hz() },
+ { 0, 1000000 / hz() }})});
+ get_safe_registers(regs);
+
+ /* Set parent's instruction pointer to start of clone-stub */
+ regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+ (unsigned long) stub_clone_handler -
+ (unsigned long) &__syscall_stub_start;
+ regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + PAGE_SIZE -
+ sizeof(void *);
+ err = ptrace_setregs(pid, regs);
+ if(err < 0)
+ panic("copy_context_skas0 : PTRACE_SETREGS failed, "
+ "pid = %d, errno = %d\n", pid, errno);
+
+ /* set a well known return code for detection of child write failure */
+ child_data->err = 12345678;
+
+ /* Wait, until parent has finished its work: read child's pid from
+ * parent's stack, and check, if bad result.
+ */
+ wait_stub_done(pid, 0, "copy_context_skas0");
+
+ pid = data->err;
+ if(pid < 0)
+ panic("copy_context_skas0 - stub-parent reports error %d\n",
+ pid);
+
+ /* Wait, until child has finished too: read child's result from
+ * child's stack and check it.
+ */
+ wait_stub_done(pid, -1, "copy_context_skas0");
+ if (child_data->err != UML_CONFIG_STUB_DATA)
+ panic("copy_context_skas0 - stub-child reports error %d\n",
+ child_data->err);
+
+ if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
+ (void *)PTRACE_O_TRACESYSGOOD) < 0)
+ panic("copy_context_skas0 : PTRACE_SETOPTIONS failed, "
+ "errno = %d\n", errno);
+
+ return pid;
+}
+
void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
void (*handler)(int))
{
@@ -334,21 +486,19 @@ void reboot_skas(void)
siglongjmp(initial_jmpbuf, INIT_JMP_REBOOT);
}
-void switch_mm_skas(int mm_fd)
+void switch_mm_skas(struct mm_id *mm_idp)
{
int err;
#warning need cpu pid in switch_mm_skas
- err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, mm_fd);
- if(err)
- panic("switch_mm_skas - PTRACE_SWITCH_MM failed, errno = %d\n",
- errno);
-}
-
-void kill_off_processes_skas(void)
-{
-#warning need to loop over userspace_pids in kill_off_processes_skas
- os_kill_ptraced_process(userspace_pid[0], 1);
+ if(proc_mm){
+ err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
+ mm_idp->u.mm_fd);
+ if(err)
+ panic("switch_mm_skas - PTRACE_SWITCH_MM failed, "
+ "errno = %d\n", errno);
+ }
+ else userspace_pid[0] = mm_idp->u.pid;
}
/*
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