[Devel] [PATCH 24/30] cr: deal with signals
Alexey Dobriyan
adobriyan at gmail.com
Thu Apr 9 19:39:28 PDT 2009
Dump signal_struct, sighand_struct.
FIXME: correstly restore, check everything
Signed-off-by: Alexey Dobriyan <adobriyan at gmail.com>
---
include/linux/cr.h | 28 ++++
include/linux/signal.h | 1
kernel/cr/Makefile | 1
kernel/cr/cpt-sys.c | 12 +
kernel/cr/cr-signal.c | 301 +++++++++++++++++++++++++++++++++++++++++++++++++
kernel/cr/cr-task.c | 14 ++
kernel/cr/cr.h | 19 +++
kernel/fork.c | 2
8 files changed, 377 insertions(+), 1 deletion(-)
--- a/include/linux/cr.h
+++ b/include/linux/cr.h
@@ -42,6 +42,8 @@ struct cr_object_header {
#define CR_OBJ_FILES_STRUCT 11
#define CR_OBJ_FD 12
#define CR_OBJ_FS_STRUCT 13
+#define CR_OBJ_SIGNAL_STRUCT 14
+#define CR_OBJ_SIGHAND_STRUCT 15
__u32 cr_type; /* object type */
__u32 cr_len; /* object length in bytes including header */
} __packed;
@@ -66,6 +68,12 @@ struct cr_image_task_struct {
cr_pos_t cr_pos_files;
cr_pos_t cr_pos_nsproxy;
+ cr_pos_t cr_pos_signal;
+ cr_pos_t cr_pos_sighand;
+ __u8 cr_blocked[16];
+ __u8 cr_real_blocked[16];
+ __u8 cr_saved_sigmask[16];
+
__u8 cr_comm[16];
/* Native arch of task, one of CR_ARCH_*. */
@@ -233,6 +241,26 @@ struct cr_image_vma_content {
/* __u8 cr_data[cr_nr_pages * cr_page_size]; */
} __packed;
+struct cr_image_signal_struct {
+ struct cr_object_header cr_hdr;
+
+ struct {
+ __u64 cr_rlim_cur;
+ __u64 cr_rlim_max;
+ } cr_rlim[16];
+} __packed;
+
+struct cr_image_sighand_struct {
+ struct cr_object_header cr_hdr;
+
+ struct {
+ __u64 cr_sa_handler;
+ __u64 cr_sa_flags;
+ __u64 cr_sa_restorer;
+ __u8 cr_sa_mask[16];
+ } cr_sa[128];
+} __packed;
+
struct cr_image_fs_struct {
struct cr_object_header cr_hdr;
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -243,6 +243,7 @@ struct pt_regs;
extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
extern void exit_signals(struct task_struct *tsk);
+extern struct kmem_cache *signal_cachep;
extern struct kmem_cache *sighand_cachep;
int unhandled_signal(struct task_struct *tsk, int sig);
--- a/kernel/cr/Makefile
+++ b/kernel/cr/Makefile
@@ -6,6 +6,7 @@ cr-y += cr-fs.o
cr-y += cr-mm.o
cr-y += cr-nsproxy.o
cr-y += cr-pid.o
+cr-y += cr-signal.o
cr-y += cr-task.o
cr-y += cr-uts.o
cr-$(CONFIG_X86_32) += cr-x86_32.o
--- a/kernel/cr/cpt-sys.c
+++ b/kernel/cr/cpt-sys.c
@@ -86,6 +86,12 @@ static int cr_collect(struct cr_context *ctx)
rv = cr_collect_all_fs_struct(ctx);
if (rv < 0)
return rv;
+ rv = cr_collect_all_signal_struct(ctx);
+ if (rv < 0)
+ return rv;
+ rv = cr_collect_all_sighand_struct(ctx);
+ if (rv < 0)
+ return rv;
rv = cr_collect_all_pid(ctx);
if (rv < 0)
return rv;
@@ -140,6 +146,12 @@ static int cr_dump(struct cr_context *ctx)
rv = cr_dump_all_uts_ns(ctx);
if (rv < 0)
return rv;
+ rv = cr_dump_all_sighand_struct(ctx);
+ if (rv < 0)
+ return rv;
+ rv = cr_dump_all_signal_struct(ctx);
+ if (rv < 0)
+ return rv;
rv = cr_dump_all_mm_struct(ctx);
if (rv < 0)
return rv;
new file mode 100644
--- /dev/null
+++ b/kernel/cr/cr-signal.c
@@ -0,0 +1,301 @@
+/* Copyright (C) 2000-2009 Parallels Holdings, Ltd. */
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include <linux/cr.h>
+#include "cr.h"
+
+static int cr_check_signal_struct(struct signal_struct *signal)
+{
+ /* FIXME locking */
+ if (!list_empty(&signal->posix_timers)) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int cr_collect_signal_struct(struct cr_context *ctx, struct signal_struct *signal)
+{
+ int rv;
+
+ rv = cr_check_signal_struct(signal);
+ if (rv < 0)
+ return rv;
+ rv = cr_collect_object(ctx, signal, CR_CTX_SIGNAL_STRUCT);
+ printk("collect signal_struct %p: rv %d\n", signal, rv);
+ return rv;
+}
+
+int cr_collect_all_signal_struct(struct cr_context *ctx)
+{
+ struct cr_object *obj;
+ int rv;
+
+ for_each_cr_object(ctx, obj, CR_CTX_TASK_STRUCT) {
+ struct task_struct *tsk = obj->o_obj;
+
+ rv = cr_collect_signal_struct(ctx, tsk->signal);
+ if (rv < 0)
+ return rv;
+ }
+ for_each_cr_object(ctx, obj, CR_CTX_SIGNAL_STRUCT) {
+ struct signal_struct *signal = obj->o_obj;
+ unsigned int cnt = atomic_read(&signal->count);
+
+ if (obj->o_count != cnt) {
+ printk("signal_struct %p has external references %lu:%u\n", signal, obj->o_count, cnt);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static int cr_dump_signal_struct(struct cr_context *ctx, struct cr_object *obj)
+{
+ struct signal_struct *signal = obj->o_obj;
+ struct cr_image_signal_struct *i;
+ int n;
+ int rv;
+
+ printk("dump signal_struct %p\n", signal);
+
+ i = cr_prepare_image(CR_OBJ_SIGNAL_STRUCT, sizeof(*i));
+ if (!i)
+ return -ENOMEM;
+
+ BUILD_BUG_ON(RLIM_NLIMITS != 16);
+ for (n = 0; n < RLIM_NLIMITS; n++) {
+ i->cr_rlim[n].cr_rlim_cur = signal->rlim[n].rlim_cur;
+ i->cr_rlim[n].cr_rlim_max = signal->rlim[n].rlim_max;
+ }
+
+ obj->o_pos = ctx->cr_dump_file->f_pos;
+ rv = cr_write(ctx, i, sizeof(*i));
+ kfree(i);
+ return rv;
+}
+
+int cr_dump_all_signal_struct(struct cr_context *ctx)
+{
+ struct cr_object *obj;
+ int rv;
+
+ for_each_cr_object(ctx, obj, CR_CTX_SIGNAL_STRUCT) {
+ rv = cr_dump_signal_struct(ctx, obj);
+ if (rv < 0)
+ return rv;
+ }
+ return 0;
+}
+
+int cr_restore_signal_struct(struct cr_context *ctx, loff_t pos)
+{
+ struct cr_image_signal_struct *i;
+ struct signal_struct *signal;
+ struct cr_object *obj;
+ int n;
+ int rv;
+
+ i = kzalloc(sizeof(*i), GFP_KERNEL);
+ if (!i)
+ return -ENOMEM;
+ rv = cr_pread(ctx, i, sizeof(*i), pos);
+ if (rv < 0) {
+ kfree(i);
+ return rv;
+ }
+ if (i->cr_hdr.cr_type != CR_OBJ_SIGNAL_STRUCT) {
+ kfree(i);
+ return -EINVAL;
+ }
+
+ signal = kmem_cache_zalloc(signal_cachep, GFP_KERNEL);
+ if (!signal) {
+ kfree(i);
+ return -ENOMEM;
+ }
+ atomic_set(&signal->count, 1);
+ atomic_set(&signal->live, 1);
+
+ for (n = 0; n < RLIM_NLIMITS; n++) {
+ signal->rlim[n].rlim_cur = i->cr_rlim[n].cr_rlim_cur;
+ signal->rlim[n].rlim_max = i->cr_rlim[n].cr_rlim_max;
+ }
+ kfree(i);
+
+ obj = cr_object_create(signal);
+ if (!obj) {
+ kmem_cache_free(signal_cachep, signal);
+ return -ENOMEM;
+ }
+ obj->o_pos = pos;
+ list_add(&obj->o_list, &ctx->cr_obj[CR_CTX_SIGNAL_STRUCT]);
+ printk("restore signal_struct %p, pos %lld\n", signal, (long long)pos);
+ return 0;
+
+}
+
+static int cr_check_sighand_struct(struct sighand_struct *sighand)
+{
+#ifdef CONFIG_SIGNALFD
+ if (waitqueue_active(&sighand->signalfd_wqh)) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+#endif
+ return 0;
+}
+
+static int cr_collect_sighand_struct(struct cr_context *ctx, struct sighand_struct *sighand)
+{
+ int rv;
+
+ rv = cr_check_sighand_struct(sighand);
+ if (rv < 0)
+ return rv;
+ rv = cr_collect_object(ctx, sighand, CR_CTX_SIGHAND_STRUCT);
+ printk("collect sighand_struct %p: rv %d\n", sighand, rv);
+ return rv;
+}
+
+int cr_collect_all_sighand_struct(struct cr_context *ctx)
+{
+ struct cr_object *obj;
+ int rv;
+
+ for_each_cr_object(ctx, obj, CR_CTX_TASK_STRUCT) {
+ struct task_struct *tsk = obj->o_obj;
+
+ rv = cr_collect_sighand_struct(ctx, tsk->sighand);
+ if (rv < 0)
+ return rv;
+ }
+ for_each_cr_object(ctx, obj, CR_CTX_SIGHAND_STRUCT) {
+ struct sighand_struct *sighand = obj->o_obj;
+ unsigned int cnt = atomic_read(&sighand->count);
+
+ if (obj->o_count != cnt) {
+ printk("sighand_struct %p has external references %lu:%u\n", sighand, obj->o_count, cnt);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static int cr_dump_sighand_struct(struct cr_context *ctx, struct cr_object *obj)
+{
+ struct sighand_struct *sighand = obj->o_obj;
+ struct cr_image_sighand_struct *i;
+ int sig;
+ int rv;
+
+ printk("dump sighand_struct %p\n", sighand);
+
+ i = cr_prepare_image(CR_OBJ_SIGHAND_STRUCT, sizeof(*i));
+ if (!i)
+ return -ENOMEM;
+
+ BUILD_BUG_ON(_NSIG > ARRAY_SIZE(i->cr_sa));
+ for (sig = 0; sig < _NSIG; sig++) {
+ struct sigaction *sa = &sighand->action[sig].sa;
+
+ i->cr_sa[sig].cr_sa_handler = cr_dump_ptr(sa->sa_handler);
+ i->cr_sa[sig].cr_sa_flags = sa->sa_flags;
+#if !defined(CONFIG_ALPHA) && !defined(CONFIG_IA64) && !defined(CONFIG_MIPS)
+ i->cr_sa[sig].cr_sa_restorer = cr_dump_ptr(sa->sa_restorer);
+#endif
+ cr_dump_sigset(i->cr_sa[sig].cr_sa_mask, &sa->sa_mask);
+ }
+
+ obj->o_pos = ctx->cr_dump_file->f_pos;
+ rv = cr_write(ctx, i, sizeof(*i));
+ kfree(i);
+ return rv;
+}
+
+int cr_dump_all_sighand_struct(struct cr_context *ctx)
+{
+ struct cr_object *obj;
+ int rv;
+
+ for_each_cr_object(ctx, obj, CR_CTX_SIGHAND_STRUCT) {
+ rv = cr_dump_sighand_struct(ctx, obj);
+ if (rv < 0)
+ return rv;
+ }
+ return 0;
+}
+
+static int __cr_restore_sighand_struct(struct cr_context *ctx, loff_t pos)
+{
+ struct cr_image_sighand_struct *i;
+ struct sighand_struct *sighand;
+ struct cr_object *obj;
+ int sig;
+ int rv;
+
+ i = kzalloc(sizeof(*i), GFP_KERNEL);
+ if (!i)
+ return -ENOMEM;
+ rv = cr_pread(ctx, i, sizeof(*i), pos);
+ if (rv < 0) {
+ kfree(i);
+ return rv;
+ }
+ if (i->cr_hdr.cr_type != CR_OBJ_SIGHAND_STRUCT) {
+ kfree(i);
+ return -EINVAL;
+ }
+
+ sighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
+ if (!sighand) {
+ kfree(i);
+ return -ENOMEM;
+ }
+ atomic_set(&sighand->count, 1);
+
+ for (sig = 0; sig < _NSIG; sig++) {
+ struct sigaction *sa = &sighand->action[sig].sa;
+
+ sa->sa_handler = cr_restore_ptr(i->cr_sa[sig].cr_sa_handler);
+ sa->sa_flags = i->cr_sa[sig].cr_sa_flags;
+#if !defined(CONFIG_ALPHA) && !defined(CONFIG_IA64) && !defined(CONFIG_MIPS)
+ sa->sa_restorer = cr_restore_ptr(i->cr_sa[sig].cr_sa_restorer);
+#endif
+ cr_restore_sigset(&sa->sa_mask, i->cr_sa[sig].cr_sa_mask);
+ }
+ kfree(i);
+
+ obj = cr_object_create(sighand);
+ if (!obj) {
+ kmem_cache_free(sighand_cachep, sighand);
+ return -ENOMEM;
+ }
+ obj->o_pos = pos;
+ list_add(&obj->o_list, &ctx->cr_obj[CR_CTX_SIGHAND_STRUCT]);
+ printk("restore sighand_struct %p, pos %lld\n", sighand, (long long)pos);
+ return 0;
+}
+
+int cr_restore_sighand_struct(struct cr_context *ctx, loff_t pos)
+{
+ struct task_struct *tsk = current;
+ struct sighand_struct *sighand;
+ struct cr_object *tmp;
+ int rv;
+
+ tmp = cr_find_obj_by_pos(ctx, pos, CR_CTX_SIGHAND_STRUCT);
+ if (!tmp) {
+ rv = __cr_restore_sighand_struct(ctx, pos);
+ if (rv < 0)
+ return rv;
+ tmp = cr_find_obj_by_pos(ctx, pos, CR_CTX_SIGHAND_STRUCT);
+ }
+ sighand = tmp->o_obj;
+ __cleanup_sighand(tsk->sighand);
+ atomic_inc(&sighand->count);
+ tsk->sighand = sighand;
+ return 0;
+}
--- a/kernel/cr/cr-task.c
+++ b/kernel/cr/cr-task.c
@@ -132,6 +132,14 @@ static int cr_dump_task_struct(struct cr_context *ctx, struct cr_object *obj)
tmp = cr_find_obj_by_ptr(ctx, tsk->files, CR_CTX_FILES_STRUCT);
i->cr_pos_files = tmp->o_pos;
+ tmp = cr_find_obj_by_ptr(ctx, tsk->signal, CR_CTX_SIGNAL_STRUCT);
+ i->cr_pos_signal = tmp->o_pos;
+ tmp = cr_find_obj_by_ptr(ctx, tsk->sighand, CR_CTX_SIGHAND_STRUCT);
+ i->cr_pos_sighand = tmp->o_pos;
+ cr_dump_sigset(i->cr_blocked, &tsk->blocked);
+ cr_dump_sigset(i->cr_real_blocked, &tsk->real_blocked);
+ cr_dump_sigset(i->cr_saved_sigmask, &tsk->saved_sigmask);
+
BUILD_BUG_ON(TASK_COMM_LEN != 16);
strlcpy((char *)i->cr_comm, (const char *)tsk->comm, sizeof(i->cr_comm));
@@ -196,6 +204,12 @@ static int task_struct_restorer(void *_tsk_ctx)
rv = cr_restore_pid(ctx, i);
if (rv < 0)
goto out;
+ rv = cr_restore_sighand_struct(ctx, i->cr_pos_sighand);
+ if (rv < 0)
+ goto out;
+ cr_restore_sigset(&tsk->blocked, i->cr_blocked);
+ cr_restore_sigset(&tsk->real_blocked, i->cr_real_blocked);
+ cr_restore_sigset(&tsk->saved_sigmask, i->cr_saved_sigmask);
rv = 0;
out:
--- a/kernel/cr/cr.h
+++ b/kernel/cr/cr.h
@@ -29,6 +29,8 @@ enum cr_context_obj_type {
CR_CTX_NSPROXY,
CR_CTX_PID,
CR_CTX_PID_NS,
+ CR_CTX_SIGHAND_STRUCT,
+ CR_CTX_SIGNAL_STRUCT,
CR_CTX_TASK_STRUCT,
CR_CTX_UTS_NS,
NR_CR_CTX_TYPES
@@ -72,6 +74,17 @@ static inline void __user *cr_restore_ptr(__u64 ptr)
return (void __user *)(unsigned long)ptr;
}
+static inline void cr_dump_sigset(__u8 *cr_image_sigset, sigset_t *sig)
+{
+ BUILD_BUG_ON(sizeof(sigset_t) > 16);
+ memcpy(cr_image_sigset, sig, sizeof(sigset_t));
+}
+
+static inline void cr_restore_sigset(sigset_t *sig, __u8 *cr_image_sigset)
+{
+ memcpy(sig, cr_image_sigset, sizeof(sigset_t));
+}
+
int cr_collect_all_files_struct(struct cr_context *ctx);
int cr_collect_all_file(struct cr_context *ctx);
int cr_collect_all_fs_struct(struct cr_context *ctx);
@@ -79,6 +92,8 @@ int cr_collect_all_mm_struct(struct cr_context *ctx);
int cr_collect_all_nsproxy(struct cr_context *ctx);
int cr_collect_all_pid_ns(struct cr_context *ctx);
int cr_collect_all_pid(struct cr_context *ctx);
+int cr_collect_all_sighand_struct(struct cr_context *ctx);
+int cr_collect_all_signal_struct(struct cr_context *ctx);
int cr_collect_all_task_struct(struct cr_context *ctx);
int cr_collect_all_uts_ns(struct cr_context *ctx);
@@ -89,6 +104,8 @@ int cr_dump_all_mm_struct(struct cr_context *ctx);
int cr_dump_all_nsproxy(struct cr_context *ctx);
int cr_dump_all_pid_ns(struct cr_context *ctx);
int cr_dump_all_pid(struct cr_context *ctx);
+int cr_dump_all_sighand_struct(struct cr_context *ctx);
+int cr_dump_all_signal_struct(struct cr_context *ctx);
int cr_dump_all_task_struct(struct cr_context *ctx);
int cr_dump_all_uts_ns(struct cr_context *ctx);
@@ -99,6 +116,8 @@ int cr_restore_mm_struct(struct cr_context *ctx, loff_t pos);
int cr_restore_nsproxy(struct cr_context *ctx, loff_t pos);
int cr_restore_pid_ns(struct cr_context *ctx, loff_t pos);
int cr_restore_pid(struct cr_context *ctx, struct cr_image_task_struct *i);
+int cr_restore_sighand_struct(struct cr_context *ctx, loff_t pos);
+int cr_restore_signal_struct(struct cr_context *ctx, loff_t pos);
int cr_restore_task_struct(struct cr_context *ctx, loff_t pos);
int cr_restore_uts_ns(struct cr_context *ctx, loff_t pos);
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -120,7 +120,7 @@ static inline void free_thread_info(struct thread_info *ti)
#endif
/* SLAB cache for signal_struct structures (tsk->signal) */
-static struct kmem_cache *signal_cachep;
+struct kmem_cache *signal_cachep;
/* SLAB cache for sighand_struct structures (tsk->sighand) */
struct kmem_cache *sighand_cachep;
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