[CRIU] [PATCH 2/9] The .c file containing the functions
Pavel Tikhomirov
snorcht at gmail.com
Tue Mar 17 11:10:57 MSK 2020
Please add more meaningful subject and description to the patches.
And I don't like splitting code movement in separate patches. Please merge them.
пн, 16 мар. 2020 г. в 19:06, prakriti goyal <prakritigoyal19 at gmail.com>:
>
> From: prakritigoyal19 <prakritigoyal19 at gmail.com>
>
> Signed-off-by: prakritigoyal19 <prakritigoyal19 at gmail.com>
> Repo link: https://github.com/prakritigoyal19/criu/tree/sigactions
>
> ---
> criu/sigaction.c | 331 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 331 insertions(+)
> create mode 100644 criu/sigaction.c
>
> diff --git a/criu/sigaction.c b/criu/sigaction.c
> new file mode 100644
> index 00000000..e5b48b44
> --- /dev/null
> +++ b/criu/sigaction.c
> @@ -0,0 +1,331 @@
> +#include <unistd.h>
> +#include <inttypes.h>
> +
> +#include <sys/stat.h>
> +#include <sys/wait.h>
> +#include <sys/mman.h>
> +
> +#include "parasite.h"
> +#include "parasite-syscall.h"
> +#include "pstree.h"
> +#include "sigframe.h"
%s/\s$//
> +
> +#include "image.h"
> +#include "img-remote.h"
> +#include "images/core.pb-c.h"
> +#include "images/sa.pb-c.h"
> +#include "infect.h"
> +#include "protobuf.h"
> +
> +#include <compel/compel.h>
> +#include "restore.h"
> +#include "restorer.h"
> +#include "sigaction.h"
> +
> +#include <compel/compel.h>
> +
> +#include "pie/pie-relocs.h"
> +
> +int parasite_dump_sigacts_seized(struct parasite_ctl *ctl, struct pstree_item *item)
> +{
> + TaskCoreEntry *tc = item->core[0]->tc;
> + struct parasite_dump_sa_args *args;
> + int ret, sig;
> + SaEntry *sa, **psa;
> +
> + args = compel_parasite_args(ctl, struct parasite_dump_sa_args);
> +
> + ret = compel_rpc_call_sync(PARASITE_CMD_DUMP_SIGACTS, ctl); //imported??
> + if (ret < 0)
> + return ret;
> +
> + psa = xmalloc((SIGMAX - 2) * (sizeof(SaEntry *) + sizeof(SaEntry))); //SIGMAX??
> + if (!psa)
> + return -1;
> +
> + sa = (SaEntry *)(psa + SIGMAX - 2);
> +
> + tc->n_sigactions = SIGMAX - 2;
> + tc->sigactions = psa;
> +
> + for (sig = 1; sig <= SIGMAX; sig++) {
> + int i = sig - 1;
> +
> + if (sig == SIGSTOP || sig == SIGKILL)
> + continue;
> +
> + sa_entry__init(sa);
> + ASSIGN_TYPED(sa->sigaction, encode_pointer(args->sas[i].rt_sa_handler)); //import???
> + ASSIGN_TYPED(sa->flags, args->sas[i].rt_sa_flags);
> + ASSIGN_TYPED(sa->restorer, encode_pointer(args->sas[i].rt_sa_restorer));
> + BUILD_BUG_ON(sizeof(sa->mask) != sizeof(args->sas[0].rt_sa_mask.sig)); //import??
> + memcpy(&sa->mask, args->sas[i].rt_sa_mask.sig, sizeof(sa->mask));
> + sa->has_compat_sigaction = true;
> + sa->compat_sigaction = !compel_mode_native(ctl);
> +
> + *(psa++) = sa++;
> + }
> +
> + return 0;
> +}
> +
> +
> +
> +rt_sigaction_t sigchld_act;
> +/*
> + * If parent's sigaction has blocked SIGKILL (which is non-sense),
> + * this parent action is non-valid and shouldn't be inherited.
> + * Used to mark parent_act* no more valid.
> + */
> +static rt_sigaction_t parent_act[SIGMAX];
> +#ifdef CONFIG_COMPAT
> +static rt_sigaction_t_compat parent_act_compat[SIGMAX];
> +#endif
> +
> +static bool sa_inherited(int sig, rt_sigaction_t *sa)
> +{
> + rt_sigaction_t *pa;
> + int i;
> +
> + if (current == root_item)
> + return false; /* XXX -- inherit from CRIU? */
> +
> + pa = &parent_act[sig];
> +
> + /* Omitting non-valid sigaction */
> + if (pa->rt_sa_mask.sig[0] & (1 << SIGKILL))
> + return false;
> +
> + for (i = 0; i < _KNSIG_WORDS; i++)
> + if (pa->rt_sa_mask.sig[i] != sa->rt_sa_mask.sig[i])
> + return false;
> +
> + return pa->rt_sa_handler == sa->rt_sa_handler &&
> + pa->rt_sa_flags == sa->rt_sa_flags &&
> + pa->rt_sa_restorer == sa->rt_sa_restorer;
> +}
> +
> +static int restore_native_sigaction(int sig, SaEntry *e)
> +{
> + rt_sigaction_t act;
> + int ret;
> +
> + ASSIGN_TYPED(act.rt_sa_handler, decode_pointer(e->sigaction));
> + ASSIGN_TYPED(act.rt_sa_flags, e->flags);
> + ASSIGN_TYPED(act.rt_sa_restorer, decode_pointer(e->restorer));
> + BUILD_BUG_ON(sizeof(e->mask) != sizeof(act.rt_sa_mask.sig));
> + memcpy(act.rt_sa_mask.sig, &e->mask, sizeof(act.rt_sa_mask.sig));
> +
> + if (sig == SIGCHLD) {
> + sigchld_act = act;
> + return 0;
> + }
> +
> + if (sa_inherited(sig - 1, &act))
> + return 1;
> +
> + /*
> + * A pure syscall is used, because glibc
> + * sigaction overwrites se_restorer.
> + */
> + ret = syscall(SYS_rt_sigaction, sig, &act, NULL, sizeof(k_rtsigset_t));
> + if (ret < 0) {
> + pr_perror("Can't restore sigaction");
> + return ret;
> + }
> +
> + parent_act[sig - 1] = act;
> + /* Mark SIGKILL blocked which makes compat sigaction non-valid */
> +#ifdef CONFIG_COMPAT
> + parent_act_compat[sig - 1].rt_sa_mask.sig[0] |= 1 << SIGKILL;
> +#endif
> +
> + return 1;
> +}
> +
> +static void *stack32;
> +
> +#ifdef CONFIG_COMPAT
> +static bool sa_compat_inherited(int sig, rt_sigaction_t_compat *sa)
> +{
> + rt_sigaction_t_compat *pa;
> + int i;
> +
> + if (current == root_item)
> + return false;
> +
> + pa = &parent_act_compat[sig];
> +
> + /* Omitting non-valid sigaction */
> + if (pa->rt_sa_mask.sig[0] & (1 << SIGKILL))
> + return false;
> +
> + for (i = 0; i < _KNSIG_WORDS; i++)
> + if (pa->rt_sa_mask.sig[i] != sa->rt_sa_mask.sig[i])
> + return false;
> +
> + return pa->rt_sa_handler == sa->rt_sa_handler &&
> + pa->rt_sa_flags == sa->rt_sa_flags &&
> + pa->rt_sa_restorer == sa->rt_sa_restorer;
> +}
> +
> +static int restore_compat_sigaction(int sig, SaEntry *e)
> +{
> + rt_sigaction_t_compat act;
> + int ret;
> +
> + ASSIGN_TYPED(act.rt_sa_handler, (u32)e->sigaction);
> + ASSIGN_TYPED(act.rt_sa_flags, e->flags);
> + ASSIGN_TYPED(act.rt_sa_restorer, (u32)e->restorer);
> + BUILD_BUG_ON(sizeof(e->mask) != sizeof(act.rt_sa_mask.sig));
> + memcpy(act.rt_sa_mask.sig, &e->mask, sizeof(act.rt_sa_mask.sig));
> +
> + if (sig == SIGCHLD) {
> + memcpy(&sigchld_act, &act, sizeof(rt_sigaction_t_compat));
> + return 0;
> + }
> +
> + if (sa_compat_inherited(sig - 1, &act))
> + return 1;
> +
> + if (!stack32) {
> + stack32 = alloc_compat_syscall_stack();
> + if (!stack32)
> + return -1;
> + }
> +
> + ret = arch_compat_rt_sigaction(stack32, sig, &act);
> + if (ret < 0) {
> + pr_err("Can't restore compat sigaction: %d\n", ret);
> + return ret;
> + }
> +
> + parent_act_compat[sig - 1] = act;
> + /* Mark SIGKILL blocked which makes native sigaction non-valid */
> + parent_act[sig - 1].rt_sa_mask.sig[0] |= 1 << SIGKILL;
> +
> + return 1;
> +}
> +#else
> +static int restore_compat_sigaction(int sig, SaEntry *e)
> +{
> + return -1;
> +}
> +#endif
> +
> +static int prepare_sigactions_from_core(TaskCoreEntry *tc)
> +{
> + int sig, i;
> +
> + if (tc->n_sigactions != SIGMAX - 2) {
> + pr_err("Bad number of sigactions in the image (%d, want %d)\n",
> + (int)tc->n_sigactions, SIGMAX - 2);
> + return -1;
> + }
> +
> + pr_info("Restore on-core sigactions for %d\n", vpid(current));
> +
> + for (sig = 1, i = 0; sig <= SIGMAX; sig++) {
> + int ret;
> + SaEntry *e;
> + bool sigaction_is_compat;
> +
> + if (sig == SIGKILL || sig == SIGSTOP)
> + continue;
> +
> + e = tc->sigactions[i++];
> + sigaction_is_compat = e->has_compat_sigaction && e->compat_sigaction;
> + if (sigaction_is_compat)
> + ret = restore_compat_sigaction(sig, e);
> + else
> + ret = restore_native_sigaction(sig, e);
> +
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +/* Returns number of restored signals, -1 or negative errno on fail */
> +static int restore_one_sigaction(int sig, struct cr_img *img, int pid)
> +{
> + bool sigaction_is_compat;
> + SaEntry *e;
> + int ret = 0;
> +
> + BUG_ON(sig == SIGKILL || sig == SIGSTOP);
> +
> + ret = pb_read_one_eof(img, &e, PB_SIGACT);
> + if (ret == 0) {
> + if (sig != SIGMAX_OLD + 1) { /* backward compatibility */
> + pr_err("Unexpected EOF %d\n", sig);
> + return -1;
> + }
> + pr_warn("This format of sigacts-%d.img is deprecated\n", pid);
> + return -1;
> + }
> + if (ret < 0)
> + return ret;
> +
> + sigaction_is_compat = e->has_compat_sigaction && e->compat_sigaction;
> + if (sigaction_is_compat)
> + ret = restore_compat_sigaction(sig, e);
> + else
> + ret = restore_native_sigaction(sig, e);
> +
> + sa_entry__free_unpacked(e, NULL);
> +
> + return ret;
> +}
> +
> +static int prepare_sigactions_from_image(void)
> +{
> + int pid = vpid(current);
> + struct cr_img *img;
> + int sig, rst = 0;
> + int ret = 0;
> +
> + pr_info("Restore sigacts for %d\n", pid);
> +
> + img = open_image(CR_FD_SIGACT, O_RSTR, pid);
> + if (!img)
> + return -1;
> +
> + for (sig = 1; sig <= SIGMAX; sig++) {
> + if (sig == SIGKILL || sig == SIGSTOP)
> + continue;
> +
> + ret = restore_one_sigaction(sig, img, pid);
> + if (ret < 0)
> + break;
> + if (ret)
> + rst++;
> + }
> +
> + pr_info("Restored %d/%d sigacts\n", rst,
> + SIGMAX - 3 /* KILL, STOP and CHLD */);
> +
> + close_image(img);
> + return ret;
> +}
> +
> +int prepare_sigactions(CoreEntry *core)
> +{
> + int ret;
> +
> + if (!task_alive(current))
> + return 0;
> +
> + if (core->tc->n_sigactions != 0)
> + ret = prepare_sigactions_from_core(core->tc);
> + else
> + ret = prepare_sigactions_from_image();
> +
> + if (stack32) {
> + free_compat_syscall_stack(stack32);
> + stack32 = NULL;
> + }
> +
> + return ret;
> +}
> \ No newline at end of file
> --
> 2.17.1
>
> _______________________________________________
> CRIU mailing list
> CRIU at openvz.org
> https://lists.openvz.org/mailman/listinfo/criu
More information about the CRIU
mailing list