diff -Naur -X exclude-files ac_cur/arch/um/include/user_util.h ac/arch/um/include/user_util.h
--- ac_cur/arch/um/include/user_util.h Tue Aug 7 09:49:45 2001
+++ ac/arch/um/include/user_util.h Tue Aug 7 10:39:52 2001
@@ -60,7 +60,8 @@
extern __u64 file_size(char *file);
extern void stop(void);
extern int proc_start_thread(unsigned long ip, unsigned long sp);
-extern void stack_protections(unsigned long address, int len);
+extern void stack_protections(unsigned long address);
+extern void task_protections(unsigned long address);
extern void abandon_proc_space(int (*proc)(void *), unsigned long sp);
extern int signals(int (*init_proc)(void *), void *sp);
extern void map(unsigned long virt, void *p, unsigned long len,
diff -Naur -X exclude-files ac_cur/arch/um/kernel/exec_kern.c ac/arch/um/kernel/exec_kern.c
--- ac_cur/arch/um/kernel/exec_kern.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/exec_kern.c Tue Aug 7 10:39:52 2001
@@ -45,11 +45,19 @@
if((vma == NULL) || (vma->vm_start > addr)) force_sigbus();
}
+/* See comment above fork_tramp for why sigstop is defined and used like
+ * this
+ */
+
+static int sigstop = SIGSTOP;
+
static int exec_tramp(void *sig_stack)
{
+ int sig = sigstop;
+
block_signals();
init_new_thread(sig_stack, NULL);
- kill(getpid(), SIGSTOP);
+ kill(getpid(), sig);
return(0);
}
@@ -71,9 +79,7 @@
current->thread.extern_pid = new_pid;
free_page(stack);
protect(physmem, high_physmem - physmem, 1, 1, 0);
- stack = (unsigned long) current;
- protect(stack + PAGE_SIZE, PAGE_SIZE, 0, 0, 0);
- stack_protections(stack + 2 * PAGE_SIZE, 2 * PAGE_SIZE);
+ task_protections((unsigned long) current);
force_flush_all();
check_brk(brk_start);
unblock_signals();
diff -Naur -X exclude-files ac_cur/arch/um/kernel/ksyms.c ac/arch/um/kernel/ksyms.c
--- ac_cur/arch/um/kernel/ksyms.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/ksyms.c Tue Aug 7 10:39:52 2001
@@ -4,6 +4,7 @@
#include "asm/delay.h"
#include "asm/processor.h"
#include "asm/unistd.h"
+#include "asm/pgalloc.h"
#include "kern_util.h"
#include "user_util.h"
@@ -18,3 +19,5 @@
EXPORT_SYMBOL(task_size);
EXPORT_SYMBOL(__do_copy_from_user);
EXPORT_SYMBOL(__do_strncpy_from_user);
+EXPORT_SYMBOL(flush_tlb_range);
+EXPORT_SYMBOL(__do_clear_user);
diff -Naur -X exclude-files ac_cur/arch/um/kernel/process.c ac/arch/um/kernel/process.c
--- ac_cur/arch/um/kernel/process.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/process.c Tue Aug 7 10:39:52 2001
@@ -102,11 +102,25 @@
init_irq_signals(sig_stack != NULL);
}
+/* This sigstop business works around a bug in gcc's -pg support.
+ * Normally a procedure's mcount call comes after esp has been copied to
+ * ebp and the new frame is constructed. With procedures with no locals,
+ * the mcount comes before, as the first thing that the procedure does.
+ * When that procedure is main for a thread, ebp comes in as NULL. So,
+ * when mcount dereferences it, it segfaults. So, UML works around this
+ * by adding a non-optimizable local to the various trampolines, fork_tramp
+ * and outer_tramp below, and exec_tramp.
+ */
+
+static int sigstop = SIGSTOP;
+
int fork_tramp(void *sig_stack)
{
+ int sig = sigstop;
+
block_signals();
init_new_thread(sig_stack, finish_fork_handler);
- kill(getpid(), SIGSTOP);
+ kill(getpid(), sig);
return(0);
}
@@ -118,15 +132,20 @@
int pid;
};
+/* See above for why sigkill is here */
+
+int sigkill = SIGKILL;
+
int outer_tramp(void *arg)
{
struct tramp *t;
+ int sig = sigkill;
t = arg;
t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
t->flags, (void *) t->stack);
if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT);
- kill(getpid(), SIGKILL);
+ kill(getpid(), sig);
exit(0);
}
@@ -155,7 +174,7 @@
if(err < 0) panic("Waiting for outer trampoline failed - errno = %d",
errno);
if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
- panic("outer trampoline didn't exit 0");
+ panic("outer trampoline didn't exit with SIGKILL");
return(arg.pid);
}
diff -Naur -X exclude-files ac_cur/arch/um/kernel/process_kern.c ac/arch/um/kernel/process_kern.c
--- ac_cur/arch/um/kernel/process_kern.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/process_kern.c Tue Aug 7 10:39:52 2001
@@ -123,7 +123,7 @@
if((page = __get_free_page(GFP_KERNEL)) == 0)
panic("Couldn't allocate new stack");
- stack_protections(page, PAGE_SIZE);
+ stack_protections(page);
return(page);
}
@@ -515,15 +515,11 @@
void finish_fork_handler(int sig)
{
- unsigned long stack;
-
init_flush_vm();
check_brk(brk_start);
if(current->mm != current->p_pptr->mm)
protect(physmem, high_physmem - physmem, 1, 1, 0);
- stack = (unsigned long) current;
- protect(stack + PAGE_SIZE, PAGE_SIZE, 0, 0, 0);
- stack_protections(stack + 2 * PAGE_SIZE, 2 * PAGE_SIZE);
+ task_protections((unsigned long) current);
if(current->thread.request.u.fork_finish.from)
schedule_tail(current->thread.request.u.fork_finish.from);
free_page(current->thread.request.u.fork_finish.stack);
diff -Naur -X exclude-files ac_cur/arch/um/kernel/trap_user.c ac/arch/um/kernel/trap_user.c
--- ac_cur/arch/um/kernel/trap_user.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/trap_user.c Tue Aug 7 10:39:52 2001
@@ -90,7 +90,7 @@
extern void signal_usr1(int sig);
-int tracing_pid;
+int tracing_pid = -1;
int signals(int (*init_proc)(void *), void *sp)
{
diff -Naur -X exclude-files ac_cur/arch/um/kernel/um_arch.c ac/arch/um/kernel/um_arch.c
--- ac_cur/arch/um/kernel/um_arch.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/um_arch.c Tue Aug 7 10:40:37 2001
@@ -295,8 +295,7 @@
#ifndef CONFIG_SMP
current = &init_task;
#endif
- protect(((unsigned long) &init_task) + PAGE_SIZE, PAGE_SIZE, 0, 0, 0);
- stack_protections(init_task.thread.kernel_stack, 2 * PAGE_SIZE);
+ task_protections((unsigned long) &init_task);
sp = (void *) init_task.thread.kernel_stack + 2 * PAGE_SIZE -
sizeof(unsigned long);
return(signals(start_kernel_proc, sp));
diff -Naur -X exclude-files ac_cur/arch/um/kernel/umid.c ac/arch/um/kernel/umid.c
--- ac_cur/arch/um/kernel/umid.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/umid.c Tue Aug 7 10:39:52 2001
@@ -32,6 +32,8 @@
return(0);
}
+extern int tracing_pid;
+
static void create_pid_file(void)
{
char file[sizeof("/tmp/uml/") + UMID_LEN + sizeof("/pid\0")];
@@ -46,7 +48,7 @@
return;
}
- sprintf(pid, "%d\n", getpid());
+ sprintf(pid, "%d\n", (tracing_pid == -1) ? getpid() : tracing_pid);
if(write(fd, pid, strlen(pid)) != strlen(pid))
printk("Write of pid file failed - errno = %d\n", errno);
close(fd);
diff -Naur -X exclude-files ac_cur/arch/um/kernel/user_util.c ac/arch/um/kernel/user_util.c
--- ac_cur/arch/um/kernel/user_util.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/kernel/user_util.c Tue Aug 7 10:39:52 2001
@@ -172,9 +172,25 @@
while(1) sleep(1000000);
}
-void stack_protections(unsigned long address, int len)
+void stack_protections(unsigned long address)
{
- mprotect((void *) address, len, PROT_READ | PROT_WRITE | PROT_EXEC);
+ int prot = PROT_READ | PROT_WRITE | PROT_EXEC;
+
+ if(mprotect((void *) address, page_size(), prot) < 0)
+ panic("protecting stack failed, errno = %d", errno);
+}
+
+void task_protections(unsigned long address)
+{
+ unsigned long guard = address + page_size();
+ unsigned long stack = guard + page_size();
+ int prot = 0;
+
+ if(mprotect((void *) stack, page_size(), prot) < 0)
+ panic("protecting guard page failed, errno = %d", errno);
+ prot = PROT_READ | PROT_WRITE | PROT_EXEC;
+ if(mprotect((void *) stack, 2 * page_size(), prot) < 0)
+ panic("protecting stack failed, errno = %d", errno);
}
void protect(unsigned long addr, unsigned long len, int r, int w, int x)
@@ -183,10 +199,8 @@
prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
(x ? PROT_EXEC : 0);
- if(mprotect((void *) addr, len, prot) == -1){
- perror("Protecting a page");
- panic("protect failed");
- }
+ if(mprotect((void *) addr, len, prot) == -1)
+ panic("protect failed, errno = %d", errno);
}
int wait_for_stop(int pid, int sig, int cont_type)
diff -Naur -X exclude-files ac_cur/arch/um/ptproxy/sysdep.c ac/arch/um/ptproxy/sysdep.c
--- ac_cur/arch/um/ptproxy/sysdep.c Tue Aug 7 09:49:45 2001
+++ ac/arch/um/ptproxy/sysdep.c Tue Aug 7 10:39:52 2001
@@ -7,6 +7,7 @@
#include <stdio.h>
#include <string.h>
+#include <stdlib.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <asm/ptrace.h>