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restore: Mmap task_restore_args by hands

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The RM_PRIVATE memory can move every time we call rst_mem_alloc,
so it's impossible to have static pointer on it. Since task args
is used actyvely, it will be easier to handle it manually.

Reported-by: Andrey Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
This commit is contained in:
Pavel Emelyanov 2016-05-25 16:28:00 +03:00
parent a839cc45f8
commit 78b94a84c1
1 changed files with 15 additions and 13 deletions
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28
criu/cr-restore.c
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@ -111,7 +111,7 @@
static struct pstree_item *current;
static int restore_task_with_children(void *);
static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core);
static int sigreturn_restore(pid_t pid, struct task_restore_args *ta, unsigned long alen, CoreEntry *core);
static int prepare_restorer_blob(void);
static int prepare_rlimits(int pid, struct task_restore_args *, CoreEntry *core);
static int prepare_posix_timers(int pid, struct task_restore_args *ta, CoreEntry *core);
@ -483,7 +483,6 @@ static int prepare_mm(pid_t pid, struct task_restore_args *args);
static int restore_one_alive_task(int pid, CoreEntry *core)
{
unsigned args_len;
unsigned long ta_cp;
struct task_restore_args *ta;
pr_info("Restoring resources\n");
@ -491,8 +490,7 @@ static int restore_one_alive_task(int pid, CoreEntry *core)
args_len = round_up(sizeof(*ta) + sizeof(struct thread_restore_args) *
current->nr_threads, page_size());
ta_cp = rst_mem_align_cpos(RM_PRIVATE);
ta = rst_mem_alloc(args_len, RM_PRIVATE);
ta = mmap(NULL, args_len, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, 0, 0);
if (!ta)
return -1;
@ -560,7 +558,7 @@ static int restore_one_alive_task(int pid, CoreEntry *core)
if (prepare_mm(pid, ta))
return -1;
return sigreturn_restore(pid, ta_cp, core);
return sigreturn_restore(pid, ta, args_len, core);
}
static void zombie_prepare_signals(void)
@ -2671,7 +2669,7 @@ static int rst_prep_creds(pid_t pid, CoreEntry *core, unsigned long *creds_pos)
return 0;
}
static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core)
static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, unsigned long alen, CoreEntry *core)
{
void *mem = MAP_FAILED;
void *restore_thread_exec_start;
@ -2684,7 +2682,6 @@ static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core)
long rst_mem_size;
long memzone_size;
struct task_restore_args *task_args;
struct thread_restore_args *thread_args;
struct restore_mem_zone *mz;
@ -2725,7 +2722,7 @@ static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core)
rst_mem_size = rst_mem_lock();
memzone_size = round_up(sizeof(struct restore_mem_zone) * current->nr_threads, page_size());
restore_bootstrap_len = restorer_len + memzone_size + rst_mem_size;
restore_bootstrap_len = restorer_len + memzone_size + alen + rst_mem_size;
BUG_ON(restore_bootstrap_len & (PAGE_SIZE - 1));
pr_info("%d threads require %ldK of memory\n",
current->nr_threads, KBYTES(restore_bootstrap_len));
@ -2791,12 +2788,17 @@ static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core)
mz = mem;
mem += memzone_size;
task_args = mremap(task_args, alen, alen, MREMAP_MAYMOVE|MREMAP_FIXED, mem);
if (task_args != mem) {
pr_perror("Can't move task args");
goto err;
}
thread_args = (struct thread_restore_args *)(task_args + 1);
mem += alen;
if (rst_mem_remap(mem))
goto err;
task_args = rst_mem_remap_ptr(ta_cp, RM_PRIVATE);
thread_args = (struct thread_restore_args *)(task_args + 1);
/*
* At this point we've found a gap in VM that fits in both -- current
* and target tasks' mappings -- and its structure is
@ -2818,8 +2820,8 @@ static int sigreturn_restore(pid_t pid, unsigned long ta_cp, CoreEntry *core)
task_args->breakpoint = &rsti(current)->breakpoint;
task_args->task_entries = rst_mem_remap_ptr(task_entries_pos, RM_SHREMAP);
task_args->rst_mem = mem;
task_args->rst_mem_size = rst_mem_size;
task_args->rst_mem = mem - alen;
task_args->rst_mem_size = rst_mem_size + alen;
task_args->bootstrap_start = (void *)exec_mem_hint;
task_args->bootstrap_len = restore_bootstrap_len;