2006-01-18 18:42:41 -07:00
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/*
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2005-04-16 16:20:36 -06:00
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* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <limits.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/utsname.h>
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#include <sys/param.h>
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#include <sys/time.h>
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#include "asm/types.h"
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#include <ctype.h>
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#include <signal.h>
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#include <wait.h>
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#include <errno.h>
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#include <stdarg.h>
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#include <sched.h>
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#include <termios.h>
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#include <string.h>
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#include "kern_util.h"
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#include "user.h"
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#include "mem_user.h"
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#include "init.h"
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#include "ptrace_user.h"
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#include "uml-config.h"
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2006-01-18 18:42:41 -07:00
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#include "os.h"
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[PATCH] uml: implement soft interrupts
This patch implements soft interrupts. Interrupt enabling and disabling no
longer map to sigprocmask. Rather, a flag is set indicating whether
interrupts may be handled. If a signal comes in and interrupts are marked as
OK, then it is handled normally. If interrupts are marked as off, then the
signal handler simply returns after noting that a signal needs handling. When
interrupts are enabled later on, this pending signals flag is checked, and the
IRQ handlers are called at that point.
The point of this is to reduce the cost of local_irq_save et al, since they
are very much more common than the signals that they are enabling and
disabling. Soft interrupts produce a speed-up of ~25% on a kernel build.
Subtleties -
UML uses sigsetjmp/siglongjmp to switch contexts. sigsetjmp has been
wrapped in a save_flags-like macro which remembers the interrupt state at
setjmp time, and restores it when it is longjmp-ed back to.
The enable_signals function has to loop because the IRQ handler
disables interrupts before returning. enable_signals has to return with
signals enabled, and signals may come in between the disabling and the
return to enable_signals. So, it loops for as long as there are pending
signals, ensuring that signals are enabled when it finally returns, and
that there are no pending signals that need to be dealt with.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 18:42:49 -07:00
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#include "longjmp.h"
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2005-04-16 16:20:36 -06:00
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void stack_protections(unsigned long address)
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{
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int prot = PROT_READ | PROT_WRITE | PROT_EXEC;
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2006-01-18 18:42:41 -07:00
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if(mprotect((void *) address, page_size(), prot) < 0)
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2005-04-16 16:20:36 -06:00
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panic("protecting stack failed, errno = %d", errno);
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}
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void task_protections(unsigned long address)
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{
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unsigned long guard = address + page_size();
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unsigned long stack = guard + page_size();
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int prot = 0, pages;
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#ifdef notdef
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if(mprotect((void *) stack, page_size(), prot) < 0)
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panic("protecting guard page failed, errno = %d", errno);
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#endif
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pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER) - 2;
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prot = PROT_READ | PROT_WRITE | PROT_EXEC;
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if(mprotect((void *) stack, pages * page_size(), prot) < 0)
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panic("protecting stack failed, errno = %d", errno);
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}
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int raw(int fd)
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{
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struct termios tt;
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int err;
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CATCH_EINTR(err = tcgetattr(fd, &tt));
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[PATCH] uml: preserve errno in error paths
The poster child for this patch is the third tuntap_user hunk. When an ioctl
fails, it properly closes the opened file descriptor and returns. However,
the close resets errno to 0, and the 'return errno' that follows returns 0
rather than the value that ioctl set. This caused the caller to believe that
the device open succeeded and had opened file descriptor 0, which caused no
end of interesting behavior.
The rest of this patch is a pass through the UML sources looking for places
where errno could be reset before being passed back out. A common culprit is
printk, which could call write, being called before errno is returned.
In some cases, where the code ends up being much smaller, I just deleted the
printk.
There was another case where a caller of run_helper looked at errno after a
failure, rather than the return value of run_helper, which was the errno value
that it wanted.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-16 20:27:49 -06:00
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if(err < 0)
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return -errno;
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2005-04-16 16:20:36 -06:00
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cfmakeraw(&tt);
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2006-01-18 18:42:41 -07:00
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CATCH_EINTR(err = tcsetattr(fd, TCSADRAIN, &tt));
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[PATCH] uml: preserve errno in error paths
The poster child for this patch is the third tuntap_user hunk. When an ioctl
fails, it properly closes the opened file descriptor and returns. However,
the close resets errno to 0, and the 'return errno' that follows returns 0
rather than the value that ioctl set. This caused the caller to believe that
the device open succeeded and had opened file descriptor 0, which caused no
end of interesting behavior.
The rest of this patch is a pass through the UML sources looking for places
where errno could be reset before being passed back out. A common culprit is
printk, which could call write, being called before errno is returned.
In some cases, where the code ends up being much smaller, I just deleted the
printk.
There was another case where a caller of run_helper looked at errno after a
failure, rather than the return value of run_helper, which was the errno value
that it wanted.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-16 20:27:49 -06:00
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if(err < 0)
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return -errno;
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2005-04-16 16:20:36 -06:00
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/* XXX tcsetattr could have applied only some changes
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* (and cfmakeraw() is a set of changes) */
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return(0);
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}
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void setup_machinename(char *machine_out)
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{
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struct utsname host;
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uname(&host);
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2006-10-11 02:21:36 -06:00
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#ifdef UML_CONFIG_UML_X86
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# ifndef UML_CONFIG_64BIT
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2005-09-21 10:39:14 -06:00
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if (!strcmp(host.machine, "x86_64")) {
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strcpy(machine_out, "i686");
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return;
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}
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2006-10-11 02:21:36 -06:00
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# else
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if (!strcmp(host.machine, "i686")) {
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strcpy(machine_out, "x86_64");
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return;
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}
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# endif
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2005-09-21 10:39:14 -06:00
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#endif
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2005-04-16 16:20:36 -06:00
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strcpy(machine_out, host.machine);
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}
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2007-05-06 15:50:59 -06:00
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void setup_hostinfo(char *buf, int len)
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2005-04-16 16:20:36 -06:00
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{
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struct utsname host;
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uname(&host);
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2007-05-06 15:50:59 -06:00
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snprintf(buf, len, "%s %s %s %s %s", host.sysname, host.nodename,
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host.release, host.version, host.machine);
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2005-04-16 16:20:36 -06:00
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}
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int setjmp_wrapper(void (*proc)(void *, void *), ...)
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{
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2006-01-18 18:42:41 -07:00
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va_list args;
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2006-04-18 23:21:41 -06:00
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jmp_buf buf;
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2005-04-16 16:20:36 -06:00
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int n;
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2006-09-26 00:32:59 -06:00
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n = UML_SETJMP(&buf);
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2005-04-16 16:20:36 -06:00
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if(n == 0){
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va_start(args, proc);
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(*proc)(&buf, &args);
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}
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va_end(args);
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2006-09-26 00:32:59 -06:00
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return n;
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2005-04-16 16:20:36 -06:00
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}
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