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[Qemu-devel] [PATCH v2 10/19] linux-user: Remove real-time signal queuin
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH v2 10/19] linux-user: Remove real-time signal queuing |
Date: |
Fri, 27 May 2016 15:51:52 +0100 |
From: Timothy E Baldwin <address@hidden>
As host signals are now blocked whenever guest signals are blocked, the
queue of realtime signals is now in Linux. The QEMU queue is now
redundant and can be removed. (We already did not queue non-RT signals, and
none of the calls to queue_signal() except the one in host_signal_handler()
pass an RT signal number.)
Signed-off-by: Timothy Edward Baldwin <address@hidden>
Message-id: address@hidden
Reviewed-by: Peter Maydell <address@hidden>
[PMM: minor commit message tweak]
Signed-off-by: Peter Maydell <address@hidden>
---
linux-user/main.c | 7 ------
linux-user/qemu.h | 11 +--------
linux-user/signal.c | 70 ++++++++++-------------------------------------------
3 files changed, 14 insertions(+), 74 deletions(-)
diff --git a/linux-user/main.c b/linux-user/main.c
index b2bc6ab..b6da0ba 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3794,14 +3794,7 @@ void stop_all_tasks(void)
/* Assumes contents are already zeroed. */
void init_task_state(TaskState *ts)
{
- int i;
-
ts->used = 1;
- ts->first_free = ts->sigqueue_table;
- for (i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++) {
- ts->sigqueue_table[i].next = &ts->sigqueue_table[i + 1];
- }
- ts->sigqueue_table[i].next = NULL;
}
CPUArchState *cpu_copy(CPUArchState *env)
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 5138289..b201f90 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -78,16 +78,9 @@ struct vm86_saved_state {
#define MAX_SIGQUEUE_SIZE 1024
-struct sigqueue {
- struct sigqueue *next;
- target_siginfo_t info;
-};
-
struct emulated_sigtable {
int pending; /* true if signal is pending */
- struct sigqueue *first;
- struct sigqueue info; /* in order to always have memory for the
- first signal, we put it here */
+ target_siginfo_t info;
};
/* NOTE: we force a big alignment so that the stack stored after is
@@ -127,8 +120,6 @@ typedef struct TaskState {
struct linux_binprm *bprm;
struct emulated_sigtable sigtab[TARGET_NSIG];
- struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
- struct sigqueue *first_free; /* first free siginfo queue entry */
/* This thread's signal mask, as requested by the guest program.
* The actual signal mask of this thread may differ:
* + we don't let SIGSEGV and SIGBUS be blocked while running guest code
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 2c6790d..5db1c0b 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -441,27 +441,6 @@ void signal_init(void)
}
}
-/* signal queue handling */
-
-static inline struct sigqueue *alloc_sigqueue(CPUArchState *env)
-{
- CPUState *cpu = ENV_GET_CPU(env);
- TaskState *ts = cpu->opaque;
- struct sigqueue *q = ts->first_free;
- if (!q)
- return NULL;
- ts->first_free = q->next;
- return q;
-}
-
-static inline void free_sigqueue(CPUArchState *env, struct sigqueue *q)
-{
- CPUState *cpu = ENV_GET_CPU(env);
- TaskState *ts = cpu->opaque;
-
- q->next = ts->first_free;
- ts->first_free = q;
-}
/* abort execution with signal */
static void QEMU_NORETURN force_sig(int target_sig)
@@ -524,37 +503,20 @@ int queue_signal(CPUArchState *env, int sig,
target_siginfo_t *info)
CPUState *cpu = ENV_GET_CPU(env);
TaskState *ts = cpu->opaque;
struct emulated_sigtable *k;
- struct sigqueue *q, **pq;
trace_user_queue_signal(env, sig);
k = &ts->sigtab[sig - 1];
- pq = &k->first;
- if (sig < TARGET_SIGRTMIN) {
- /* if non real time signal, we queue exactly one signal */
- if (!k->pending)
- q = &k->info;
- else
- return 0;
- } else {
- if (!k->pending) {
- /* first signal */
- q = &k->info;
- } else {
- q = alloc_sigqueue(env);
- if (!q)
- return -EAGAIN;
- while (*pq != NULL)
- pq = &(*pq)->next;
- }
- }
- *pq = q;
- q->info = *info;
- q->next = NULL;
- k->pending = 1;
- /* signal that a new signal is pending */
- atomic_set(&ts->signal_pending, 1);
- return 1; /* indicates that the signal was queued */
+ /* we queue exactly one signal */
+ if (k->pending) {
+ return 0;
+ }
+
+ k->info = *info;
+ k->pending = 1;
+ /* signal that a new signal is pending */
+ atomic_set(&ts->signal_pending, 1);
+ return 1; /* indicates that the signal was queued */
}
#ifndef HAVE_SAFE_SYSCALL
@@ -5783,16 +5745,12 @@ static void handle_pending_signal(CPUArchState
*cpu_env, int sig)
sigset_t set;
target_sigset_t target_old_set;
struct target_sigaction *sa;
- struct sigqueue *q;
TaskState *ts = cpu->opaque;
struct emulated_sigtable *k = &ts->sigtab[sig - 1];
trace_user_handle_signal(cpu_env, sig);
/* dequeue signal */
- q = k->first;
- k->first = q->next;
- if (!k->first)
- k->pending = 0;
+ k->pending = 0;
sig = gdb_handlesig(cpu, sig);
if (!sig) {
@@ -5857,10 +5815,10 @@ static void handle_pending_signal(CPUArchState
*cpu_env, int sig)
#if defined(TARGET_ABI_MIPSN32) || defined(TARGET_ABI_MIPSN64) \
|| defined(TARGET_OPENRISC) || defined(TARGET_TILEGX)
/* These targets do not have traditional signals. */
- setup_rt_frame(sig, sa, &q->info, &target_old_set, cpu_env);
+ setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env);
#else
if (sa->sa_flags & TARGET_SA_SIGINFO)
- setup_rt_frame(sig, sa, &q->info, &target_old_set, cpu_env);
+ setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env);
else
setup_frame(sig, sa, &target_old_set, cpu_env);
#endif
@@ -5868,8 +5826,6 @@ static void handle_pending_signal(CPUArchState *cpu_env,
int sig)
sa->_sa_handler = TARGET_SIG_DFL;
}
}
- if (q != &k->info)
- free_sigqueue(cpu_env, q);
}
void process_pending_signals(CPUArchState *cpu_env)
--
1.9.1
- [Qemu-devel] [PATCH v2 00/19] linux-user: fix various signal race conditions, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 16/19] linux-user: Restart fork() if signals pending, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 18/19] linux-user: Avoid possible misalignment in host_to_target_siginfo(), Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 14/19] linux-user: Restart exit() if signal pending, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 11/19] linux-user: Queue synchronous signals separately, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 12/19] linux-user: Block signals during sigaction() handling, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 13/19] linux-user: pause() should not pause if signal pending, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 03/19] linux-user: Fix stray tab-indent, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 09/19] linux-user: Remove redundant gdb_queuesig(), Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 08/19] linux-user: Remove redundant default action check in queue_signal(), Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 10/19] linux-user: Remove real-time signal queuing,
Peter Maydell <=
- [Qemu-devel] [PATCH v2 06/19] linux-user: Use safe_syscall for sigsuspend syscalls, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 05/19] linux-user: Define macro for size of host kernel sigset_t, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 07/19] linux-user: Fix race between multiple signals, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 02/19] linux-user: Move handle_pending_signal() to avoid need for declaration, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 01/19] linux-user: Factor out handle_signal code from process_pending_signals(), Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 04/19] linux-user: Factor out uses of do_sigprocmask() from sigreturn code, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 15/19] linux-user: Use safe_syscall for kill, tkill and tgkill syscalls, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 17/19] linux-user: Use both si_code and si_signo when converting siginfo_t, Peter Maydell, 2016/05/27
- [Qemu-devel] [PATCH v2 19/19] linux-user: Avoid possible misalignment in target_to_host_siginfo(), Peter Maydell, 2016/05/27