On 2.4 hosts signals are delivered in numeric order when there are multiple
pending at a given time. UML developed a subtle dependency on this ordering,
which broke on 2.6 hosts and the separate process and thread signal queues.
This patch eliminates that dependency.
Signed-off-by: Jeff Dike <[email protected]>
Index: 2.6.9-rc2/arch/um/kernel/process.c
===================================================================
--- 2.6.9-rc2.orig/arch/um/kernel/process.c 2004-09-14 13:48:41.000000000 -0400
+++ 2.6.9-rc2/arch/um/kernel/process.c 2004-09-14 13:49:43.000000000 -0400
@@ -70,7 +70,7 @@
set_handler(SIGWINCH, (__sighandler_t) sig_handler, flags,
SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
set_handler(SIGUSR2, (__sighandler_t) sig_handler,
- SA_NOMASK | flags, -1);
+ flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
signal(SIGHUP, SIG_IGN);
init_irq_signals(altstack);
Index: 2.6.9-rc2/arch/um/kernel/tt/exec_kern.c
===================================================================
--- 2.6.9-rc2.orig/arch/um/kernel/tt/exec_kern.c 2004-09-14 13:48:41.000000000 -0400
+++ 2.6.9-rc2/arch/um/kernel/tt/exec_kern.c 2004-09-14 13:49:43.000000000 -0400
@@ -14,6 +14,7 @@
#include "kern_util.h"
#include "irq_user.h"
#include "time_user.h"
+#include "signal_user.h"
#include "mem_user.h"
#include "os.h"
#include "tlb.h"
@@ -53,7 +54,9 @@
current->thread.request.u.exec.pid = new_pid;
unprotect_stack((unsigned long) current_thread);
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
+ change_sig(SIGUSR1, 0);
enable_timer();
free_page(stack);
protect_memory(uml_reserved, high_physmem - uml_reserved, 1, 1, 0, 1);
Index: 2.6.9-rc2/arch/um/kernel/tt/process_kern.c
===================================================================
--- 2.6.9-rc2.orig/arch/um/kernel/tt/process_kern.c 2004-09-14 13:48:41.000000000 -0400
+++ 2.6.9-rc2/arch/um/kernel/tt/process_kern.c 2004-09-14 13:49:43.000000000 -0400
@@ -201,6 +201,7 @@
local_irq_disable();
init_new_thread_stack(stack, new_thread_handler);
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
return(0);
}
@@ -244,6 +245,7 @@
init_new_thread_stack(stack, finish_fork_handler);
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
return(0);
}
@@ -295,19 +297,30 @@
current->thread.request.op = OP_FORK;
current->thread.request.u.fork.pid = new_pid;
os_usr1_process(os_getpid());
- return(0);
+
+ /* Enable the signal and then disable it to ensure that it is handled
+ * here, and nowhere else.
+ */
+ change_sig(SIGUSR1, 1);
+
+ change_sig(SIGUSR1, 0);
+ err = 0;
+ out:
+ return(err);
}
void reboot_tt(void)
{
current->thread.request.op = OP_REBOOT;
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
}
void halt_tt(void)
{
current->thread.request.op = OP_HALT;
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
}
void kill_off_processes_tt(void)
@@ -334,6 +347,9 @@
current->thread.request.u.cb.proc = proc;
current->thread.request.u.cb.arg = arg;
os_usr1_process(os_getpid());
+ change_sig(SIGUSR1, 1);
+
+ change_sig(SIGUSR1, 0);
}
}
Index: 2.6.9-rc2/arch/um/kernel/tt/trap_user.c
===================================================================
--- 2.6.9-rc2.orig/arch/um/kernel/tt/trap_user.c 2004-09-14 13:48:41.000000000 -0400
+++ 2.6.9-rc2/arch/um/kernel/tt/trap_user.c 2004-09-14 13:49:43.000000000 -0400
@@ -37,7 +37,6 @@
if(sig != SIGUSR2)
r->syscall = -1;
- change_sig(SIGUSR1, 1);
info = &sig_info[sig];
if(!info->is_irq) unblock_signals();
@@ -46,7 +45,6 @@
if(is_user){
interrupt_end();
block_signals();
- change_sig(SIGUSR1, 0);
set_user_mode(NULL);
}
*r = save_regs;
Index: 2.6.9-rc2/arch/um/os-Linux/process.c
===================================================================
--- 2.6.9-rc2.orig/arch/um/os-Linux/process.c 2004-09-14 13:48:41.000000000 -0400
+++ 2.6.9-rc2/arch/um/os-Linux/process.c 2004-09-14 13:49:43.000000000 -0400
@@ -96,11 +96,7 @@
void os_usr1_process(int pid)
{
-#ifdef __NR_tkill
- syscall(__NR_tkill, pid, SIGUSR1);
-#else
kill(pid, SIGUSR1);
-#endif
}
int os_getpid(void)