This patch adds checkpoint and restart of rlimit information that is part of shared signal_struct. Changelog[v19-rc3]: - Rebase to kernel 2.6.33 Signed-off-by: Oren Laadan <orenl@xxxxxxxxxxxxxxx> Acked-by: Louis Rilling <Louis.Rilling@xxxxxxxxxxx> Acked-by: Serge E. Hallyn <serue@xxxxxxxxxx> Tested-by: Serge E. Hallyn <serue@xxxxxxxxxx> --- checkpoint/checkpoint.c | 2 ++ checkpoint/restart.c | 3 +++ checkpoint/signal.c | 27 +++++++++++++++++++++++---- include/linux/checkpoint_hdr.h | 17 +++++++++++++++++ include/linux/resource.h | 1 + kernel/sys.c | 36 +++++++++++++++++++++++------------- 6 files changed, 69 insertions(+), 17 deletions(-) diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c index 445fef7..71a4bec 100644 --- a/checkpoint/checkpoint.c +++ b/checkpoint/checkpoint.c @@ -122,6 +122,8 @@ static void fill_kernel_const(struct ckpt_const *h) h->uts_version_len = sizeof(uts->version); h->uts_machine_len = sizeof(uts->machine); h->uts_domainname_len = sizeof(uts->domainname); + /* rlimit */ + h->rlimit_nlimits = RLIM_NLIMITS; } /* write the checkpoint header */ diff --git a/checkpoint/restart.c b/checkpoint/restart.c index 026911e..863ee87 100644 --- a/checkpoint/restart.c +++ b/checkpoint/restart.c @@ -583,6 +583,9 @@ static int check_kernel_const(struct ckpt_const *h) return -EINVAL; if (h->uts_domainname_len != sizeof(uts->domainname)) return -EINVAL; + /* rlimit */ + if (h->rlimit_nlimits != RLIM_NLIMITS) + return -EINVAL; return 0; } diff --git a/checkpoint/signal.c b/checkpoint/signal.c index fedb8f8..5884462 100644 --- a/checkpoint/signal.c +++ b/checkpoint/signal.c @@ -14,6 +14,7 @@ #include <linux/sched.h> #include <linux/signal.h> #include <linux/errno.h> +#include <linux/resource.h> #include <linux/checkpoint.h> #include <linux/checkpoint_hdr.h> @@ -169,13 +170,22 @@ int restore_obj_sighand(struct ckpt_ctx *ctx, int sighand_objref) static int checkpoint_signal(struct ckpt_ctx *ctx, struct task_struct *t) { struct ckpt_hdr_signal *h; + struct signal_struct *signal; + struct rlimit *rlim; int ret; h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_SIGNAL); if (!h) return -ENOMEM; - /* fill in later */ + signal = t->signal; + rlim = signal->rlim; + + /* rlimit */ + for (i = 0; i < RLIM_NLIMITS; i++) { + h->rlim[i].rlim_cur = rlim[i].rlim_cur; + h->rlim[i].rlim_max = rlim[i].rlim_max; + } ret = ckpt_write_obj(ctx, &h->h); ckpt_hdr_put(ctx, h); @@ -191,15 +201,24 @@ int checkpoint_obj_signal(struct ckpt_ctx *ctx, struct task_struct *t) static int restore_signal(struct ckpt_ctx *ctx) { struct ckpt_hdr_signal *h; + struct rlimit rlim; + int i, ret; h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_SIGNAL); if (IS_ERR(h)) return PTR_ERR(h); - /* fill in later */ - + /* rlimit */ + for (i = 0; i < RLIM_NLIMITS; i++) { + rlim.rlim_cur = h->rlim[i].rlim_cur; + rlim.rlim_max = h->rlim[i].rlim_max; + ret = do_setrlimit(i, &rlim); + if (ret < 0) + break; + } + out: ckpt_hdr_put(ctx, h); - return 0; + return ret; } int restore_obj_signal(struct ckpt_ctx *ctx, int signal_objref) diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h index 535ea93..39302a6 100644 --- a/include/linux/checkpoint_hdr.h +++ b/include/linux/checkpoint_hdr.h @@ -212,6 +212,8 @@ struct ckpt_const { __u16 uts_version_len; __u16 uts_machine_len; __u16 uts_domainname_len; + /* rlimit */ + __u16 rlimit_nlimits; } __attribute__((aligned(8))); /* checkpoint image header */ @@ -538,8 +540,23 @@ struct ckpt_hdr_sighand { struct ckpt_sigaction action[0]; } __attribute__((aligned(8))); +struct ckpt_rlimit { + __u64 rlim_cur; + __u64 rlim_max; +} __attribute__((aligned(8))); + +/* cannot include <linux/resource.h> from userspace, so define: */ +#define CKPT_RLIM_NLIMITS 16 +#ifdef __KERNEL__ +#include <linux/resource.h> +#if CKPT_RLIM_NLIMITS != RLIM_NLIMITS +#error CKPT_RLIM_NLIMIT size is wrong per asm-generic/resource.h +#endif +#endif + struct ckpt_hdr_signal { struct ckpt_hdr h; + struct ckpt_rlimit rlim[CKPT_RLIM_NLIMITS]; } __attribute__((aligned(8))); struct ckpt_hdr_signal_task { diff --git a/include/linux/resource.h b/include/linux/resource.h index f1e914e..35f6163 100644 --- a/include/linux/resource.h +++ b/include/linux/resource.h @@ -73,6 +73,7 @@ struct rlimit { struct task_struct; int getrusage(struct task_struct *p, int who, struct rusage __user *ru); +int do_setrlimit(unsigned int resource, struct rlimit *rlim); #endif /* __KERNEL__ */ diff --git a/kernel/sys.c b/kernel/sys.c index 0df737a..033c650 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1149,40 +1149,39 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, #endif -SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) +int do_setrlimit(unsigned int resource, struct rlimit *new_rlim) { - struct rlimit new_rlim, *old_rlim; + struct rlimit *old_rlim; int retval; if (resource >= RLIM_NLIMITS) return -EINVAL; - if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) - return -EFAULT; - if (new_rlim.rlim_cur > new_rlim.rlim_max) + if (new_rlim->rlim_cur > new_rlim->rlim_max) return -EINVAL; + old_rlim = current->signal->rlim + resource; - if ((new_rlim.rlim_max > old_rlim->rlim_max) && + if ((new_rlim->rlim_max > old_rlim->rlim_max) && !capable(CAP_SYS_RESOURCE)) return -EPERM; - if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) + if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open) return -EPERM; - retval = security_task_setrlimit(resource, &new_rlim); + retval = security_task_setrlimit(resource, new_rlim); if (retval) return retval; - if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { + if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { /* * The caller is asking for an immediate RLIMIT_CPU * expiry. But we use the zero value to mean "it was * never set". So let's cheat and make it one second * instead */ - new_rlim.rlim_cur = 1; + new_rlim->rlim_cur = 1; } task_lock(current->group_leader); - *old_rlim = new_rlim; + *old_rlim = *new_rlim; task_unlock(current->group_leader); if (resource != RLIMIT_CPU) @@ -1194,14 +1193,25 @@ SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) * very long-standing error, and fixing it now risks breakage of * applications, so we live with it */ - if (new_rlim.rlim_cur == RLIM_INFINITY) + if (new_rlim->rlim_cur == RLIM_INFINITY) goto out; - update_rlimit_cpu(new_rlim.rlim_cur); + update_rlimit_cpu(new_rlim->rlim_cur); out: return 0; } +SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) +{ + struct rlimit new_rlim; + + if (resource >= RLIM_NLIMITS) + return -EINVAL; + if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) + return -EFAULT; + return do_setrlimit(resource, &new_rlim); +} + /* * It would make sense to put struct rusage in the task_struct, * except that would make the task_struct be *really big*. 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