lkml.org 
[lkml]   [2009]   [May]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC v16][PATCH 06/43] c/r: x86_32 support for checkpoint/restart
    Date
    Add logic to save and restore architecture specific state, including
    thread-specific state, CPU registers and FPU state.

    In addition, architecture capabilities are saved in an architecure
    specific extension of the header (ckpt_hdr_head_arch); Currently this
    includes only FPU capabilities.

    Currently only x86-32 is supported.

    TODO: validate input values for regs, debug regs, and TLS on restart.

    Changelog[v16]:
    - All objects are preceded by ckpt_hdr (TLS and xstate_buf)
    - Add architecture identifier to main header

    Changelog[v14]:
    - Use new interface ckpt_hdr_get/put()
    - Embed struct ckpt_hdr in struct ckpt_hdr...
    - Remove preempt_disable/enable() around init_fpu() and fix leak
    - Revert change to pr_debug(), back to ckpt_debug()
    - Move code related to task_struct to checkpoint/process.c

    Changelog[v12]:
    - A couple of missed calls to ckpt_hbuf_put()
    - Replace obsolete ckpt_debug() with pr_debug()

    Changelog[v9]:
    - Add arch-specific header that details architecture capabilities;
    split FPU restore to send capabilities only once.
    - Test for zero TLS entries in ckpt_write_thread()
    - Fix asm/checkpoint_hdr.h so it can be included from user-space

    Changelog[v7]:
    - Fix save/restore state of FPU

    Changelog[v5]:
    - Remove preempt_disable() when restoring debug registers

    Changelog[v4]:
    - Fix header structure alignment

    Changelog[v2]:
    - Pad header structures to 64 bits to ensure compatibility
    - Follow Dave Hansen's refactoring of the original post

    Signed-off-by: Oren Laadan <orenl@cs.columbia.edu>
    ---
    arch/x86/include/asm/checkpoint_hdr.h | 110 +++++++++
    arch/x86/mm/Makefile | 2 +
    arch/x86/mm/checkpoint.c | 431 +++++++++++++++++++++++++++++++++
    checkpoint/checkpoint.c | 7 +-
    checkpoint/process.c | 20 ++-
    checkpoint/restart.c | 6 +
    include/linux/checkpoint.h | 10 +
    include/linux/checkpoint_hdr.h | 12 +-
    8 files changed, 594 insertions(+), 4 deletions(-)

    diff --git a/arch/x86/include/asm/checkpoint_hdr.h b/arch/x86/include/asm/checkpoint_hdr.h
    new file mode 100644
    index 0000000..362b499
    --- /dev/null
    +++ b/arch/x86/include/asm/checkpoint_hdr.h
    @@ -0,0 +1,110 @@
    +#ifndef __ASM_X86_CKPT_HDR_H
    +#define __ASM_X86_CKPT_HDR_H
    +/*
    + * Checkpoint/restart - architecture specific headers x86
    + *
    + * Copyright (C) 2008-2009 Oren Laadan
    + *
    + * This file is subject to the terms and conditions of the GNU General Public
    + * License. See the file COPYING in the main directory of the Linux
    + * distribution for more details.
    + */
    +
    +#include <linux/types.h>
    +#include <linux/checkpoint_hdr.h>
    +
    +/*
    + * To maintain compatibility between 32-bit and 64-bit architecture flavors,
    + * keep data 64-bit aligned: use padding for structure members, and use
    + * __attribute__((aligned (8))) for the entire structure.
    + *
    + * Quoting Arnd Bergmann:
    + * "This structure has an odd multiple of 32-bit members, which means
    + * that if you put it into a larger structure that also contains 64-bit
    + * members, the larger structure may get different alignment on x86-32
    + * and x86-64, which you might want to avoid. I can't tell if this is
    + * an actual problem here. ... In this case, I'm pretty sure that
    + * sizeof(ckpt_hdr_task) on x86-32 is different from x86-64, since it
    + * will be 32-bit aligned on x86-32."
    + */
    +
    +/* i387 structure seen from kernel/userspace */
    +#ifdef __KERNEL__
    +#include <asm/processor.h>
    +#else
    +#include <sys/user.h>
    +#endif
    +
    +#ifndef CONFIG_X86_64
    +#define CKPT_ARCH_ID CKPT_ARCH_X86_32
    +#endif
    +
    +/* arch dependent header types */
    +enum {
    + CKPT_HDR_THREAD_TLS = 201,
    + CKPT_HDR_CPU_FPU,
    +};
    +
    +struct ckpt_hdr_header_arch {
    + struct ckpt_hdr h;
    + /* FIXME: add HAVE_HWFP */
    + __u16 has_fxsr;
    + __u16 has_xsave;
    + __u16 xstate_size;
    + __u16 _pading;
    +} __attribute__((aligned(8)));
    +
    +struct ckpt_hdr_thread {
    + struct ckpt_hdr h;
    + /* FIXME: restart blocks */
    + __u16 gdt_entry_tls_entries;
    + __u16 sizeof_tls_array;
    + __u16 ntls; /* number of TLS entries to follow */
    +} __attribute__((aligned(8)));
    +
    +struct ckpt_hdr_cpu {
    + struct ckpt_hdr h;
    + /* see struct pt_regs (x86-64) */
    + __u64 r15;
    + __u64 r14;
    + __u64 r13;
    + __u64 r12;
    + __u64 bp;
    + __u64 bx;
    + __u64 r11;
    + __u64 r10;
    + __u64 r9;
    + __u64 r8;
    + __u64 ax;
    + __u64 cx;
    + __u64 dx;
    + __u64 si;
    + __u64 di;
    + __u64 orig_ax;
    + __u64 ip;
    + __u64 cs;
    + __u64 flags;
    + __u64 sp;
    + __u64 ss;
    +
    + /* segment registers */
    + __u64 ds;
    + __u64 es;
    + __u64 fs;
    + __u64 gs;
    +
    + /* debug registers */
    + __u64 debugreg0;
    + __u64 debugreg1;
    + __u64 debugreg2;
    + __u64 debugreg3;
    + __u64 debugreg6;
    + __u64 debugreg7;
    +
    + __u32 uses_debug;
    + __u32 used_math;
    +
    + /* thread_xstate contents follow (if used_math) */
    +} __attribute__((aligned(8)));
    +
    +#endif /* __ASM_X86_CKPT_HDR__H */
    diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
    index fdd30d0..7d894a5 100644
    --- a/arch/x86/mm/Makefile
    +++ b/arch/x86/mm/Makefile
    @@ -19,3 +19,5 @@ obj-$(CONFIG_K8_NUMA) += k8topology_64.o
    obj-$(CONFIG_ACPI_NUMA) += srat_$(BITS).o

    obj-$(CONFIG_MEMTEST) += memtest.o
    +
    +obj-$(CONFIG_CHECKPOINT) += checkpoint.o
    diff --git a/arch/x86/mm/checkpoint.c b/arch/x86/mm/checkpoint.c
    new file mode 100644
    index 0000000..f54fe80
    --- /dev/null
    +++ b/arch/x86/mm/checkpoint.c
    @@ -0,0 +1,431 @@
    +/*
    + * Checkpoint/restart - architecture specific support for x86
    + *
    + * Copyright (C) 2008-2009 Oren Laadan
    + *
    + * This file is subject to the terms and conditions of the GNU General Public
    + * License. See the file COPYING in the main directory of the Linux
    + * distribution for more details.
    + */
    +
    +/* default debug level for output */
    +#define CKPT_DFLAG CKPT_DSYS
    +
    +#include <asm/desc.h>
    +#include <asm/i387.h>
    +
    +#include <asm/checkpoint_hdr.h>
    +#include <linux/checkpoint.h>
    +
    +/**************************************************************************
    + * Checkpoint
    + */
    +
    +/* dump the thread_struct of a given task */
    +int checkpoint_thread(struct ckpt_ctx *ctx, struct task_struct *t)
    +{
    + struct ckpt_hdr_thread *h;
    + struct thread_struct *thread;
    + struct desc_struct *desc;
    + int ntls = 0;
    + int n, ret;
    +
    + h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_THREAD);
    + if (!h)
    + return -ENOMEM;
    +
    + thread = &t->thread;
    +
    + /* calculate no. of TLS entries that follow */
    + desc = thread->tls_array;
    + for (n = GDT_ENTRY_TLS_ENTRIES; n > 0; n--, desc++) {
    + if (desc->a || desc->b)
    + ntls++;
    + }
    +
    + h->gdt_entry_tls_entries = GDT_ENTRY_TLS_ENTRIES;
    + h->sizeof_tls_array = sizeof(thread->tls_array);
    + h->ntls = ntls;
    +
    + ret = ckpt_write_obj(ctx, &h->h);
    + ckpt_hdr_put(ctx, h);
    + if (ret < 0)
    + return ret;
    +
    + ckpt_debug("ntls %d\n", ntls);
    + if (ntls == 0)
    + return 0;
    +
    + /*
    + * For simplicity dump the entire array, cherry-pick upon restart
    + * FIXME: the TLS descriptors in the GDT should be called out and
    + * not tied to the in-kernel representation.
    + */
    + ret = ckpt_write_obj_type(ctx, thread->tls_array,
    + sizeof(thread->tls_array),
    + CKPT_HDR_THREAD_TLS);
    +
    + /* IGNORE RESTART BLOCKS FOR NOW ... */
    +
    + return ret;
    +}
    +
    +#ifndef CONFIG_X86_64
    +
    +static void save_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + struct thread_struct *thread = &t->thread;
    + struct pt_regs *regs = task_pt_regs(t);
    +
    + h->bp = regs->bp;
    + h->bx = regs->bx;
    + h->ax = regs->ax;
    + h->cx = regs->cx;
    + h->dx = regs->dx;
    + h->si = regs->si;
    + h->di = regs->di;
    + h->orig_ax = regs->orig_ax;
    + h->ip = regs->ip;
    + h->cs = regs->cs;
    + h->flags = regs->flags;
    + h->sp = regs->sp;
    + h->ss = regs->ss;
    +
    + h->ds = regs->ds;
    + h->es = regs->es;
    +
    + /*
    + * for checkpoint in process context (from within a container)
    + * the GS and FS registers should be saved from the hardware;
    + * otherwise they are already sabed on the thread structure
    + */
    + if (t == current) {
    + savesegment(gs, h->gs);
    + savesegment(fs, h->fs);
    + } else {
    + h->gs = thread->gs;
    + h->fs = thread->fs;
    + }
    +
    + /*
    + * for checkpoint in process context (from within a container),
    + * the actual syscall is taking place at this very moment; so
    + * we (optimistically) subtitute the future return value (0) of
    + * this syscall into the orig_eax, so that upon restart it will
    + * succeed (or it will endlessly retry checkpoint...)
    + */
    + if (t == current) {
    + BUG_ON(h->orig_ax < 0);
    + h->ax = 0;
    + }
    +}
    +
    +static void save_cpu_debug(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + struct thread_struct *thread = &t->thread;
    +
    + /* debug regs */
    +
    + /*
    + * for checkpoint in process context (from within a container),
    + * get the actual registers; otherwise get the saved values.
    + */
    +
    + if (t == current) {
    + get_debugreg(h->debugreg0, 0);
    + get_debugreg(h->debugreg1, 1);
    + get_debugreg(h->debugreg2, 2);
    + get_debugreg(h->debugreg3, 3);
    + get_debugreg(h->debugreg6, 6);
    + get_debugreg(h->debugreg7, 7);
    + } else {
    + h->debugreg0 = thread->debugreg0;
    + h->debugreg1 = thread->debugreg1;
    + h->debugreg2 = thread->debugreg2;
    + h->debugreg3 = thread->debugreg3;
    + h->debugreg6 = thread->debugreg6;
    + h->debugreg7 = thread->debugreg7;
    + }
    +
    + h->uses_debug = !!(task_thread_info(t)->flags & TIF_DEBUG);
    +}
    +
    +static void save_cpu_fpu(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + h->used_math = tsk_used_math(t) ? 1 : 0;
    +}
    +
    +static int checkpoint_cpu_fpu(struct ckpt_ctx *ctx, struct task_struct *t)
    +{
    + struct ckpt_hdr *h;
    + int ret;
    +
    + h = ckpt_hdr_get_type(ctx, xstate_size + sizeof(*h),
    + CKPT_HDR_CPU_FPU);
    + if (!h)
    + return -ENOMEM;
    +
    + /* i387 + MMU + SSE logic */
    + preempt_disable(); /* needed it (t == current) */
    +
    + /*
    + * normally, no need to unlazy_fpu(), since TS_USEDFPU flag
    + * was cleared when task was context-switched out...
    + * except if we are in process context, in which case we do
    + */
    + if (t == current && (task_thread_info(t)->status & TS_USEDFPU))
    + unlazy_fpu(current);
    +
    + /*
    + * For simplicity dump the entire structure.
    + * FIX: need to be deliberate about what registers we are
    + * dumping for traceability and compatibility.
    + */
    + memcpy(h + 1, t->thread.xstate, xstate_size);
    + preempt_enable(); /* needed if (t == current) */
    +
    + ret = ckpt_write_obj(ctx, h);
    + ckpt_hdr_put(ctx, h);
    +
    + return ret;
    +}
    +
    +#endif /* !CONFIG_X86_64 */
    +
    +/* dump the cpu state and registers of a given task */
    +int checkpoint_cpu(struct ckpt_ctx *ctx, struct task_struct *t)
    +{
    + struct ckpt_hdr_cpu *h;
    + int ret;
    +
    + h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_CPU);
    + if (!h)
    + return -ENOMEM;
    +
    + save_cpu_regs(h, t);
    + save_cpu_debug(h, t);
    + save_cpu_fpu(h, t);
    +
    + ckpt_debug("math %d debug %d\n", h->used_math, h->uses_debug);
    +
    + ret = ckpt_write_obj(ctx, &h->h);
    + if (ret < 0)
    + goto out;
    +
    + if (h->used_math)
    + ret = checkpoint_cpu_fpu(ctx, t);
    + out:
    + ckpt_hdr_put(ctx, h);
    + return ret;
    +}
    +
    +int checkpoint_write_header_arch(struct ckpt_ctx *ctx)
    +{
    + struct ckpt_hdr_header_arch *h;
    + int ret;
    +
    + h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_HEADER_ARCH);
    + if (!h)
    + return -ENOMEM;
    +
    + /* FPU capabilities */
    + h->has_fxsr = cpu_has_fxsr;
    + h->has_xsave = cpu_has_xsave;
    + h->xstate_size = xstate_size;
    +
    + ret = ckpt_write_obj(ctx, &h->h);
    + ckpt_hdr_put(ctx, h);
    +
    + return ret;
    +}
    +
    +/**************************************************************************
    + * Restart
    + */
    +
    +/* read the thread_struct into the current task */
    +int restore_thread(struct ckpt_ctx *ctx)
    +{
    + struct ckpt_hdr_thread *h;
    + struct task_struct *t = current;
    + struct thread_struct *thread = &t->thread;
    + int ret;
    +
    + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_THREAD);
    + if (IS_ERR(h))
    + return PTR_ERR(h);
    +
    + ckpt_debug("ntls %d\n", h->ntls);
    +
    + ret = -EINVAL;
    + if (h->gdt_entry_tls_entries != GDT_ENTRY_TLS_ENTRIES ||
    + h->sizeof_tls_array != sizeof(thread->tls_array) ||
    + h->ntls > GDT_ENTRY_TLS_ENTRIES)
    + goto out;
    +
    + if (h->ntls > 0) {
    + struct ckpt_hdr *hh;
    + int size, cpu;
    +
    + /*
    + * restore TLS by hand: why convert to struct user_desc if
    + * sys_set_thread_entry() will convert it back ?
    + */
    +
    + size = sizeof(struct desc_struct) * GDT_ENTRY_TLS_ENTRIES;
    + hh = ckpt_read_obj_type(ctx, size + sizeof(*hh),
    + CKPT_HDR_THREAD_TLS);
    + if (IS_ERR(hh)) {
    + ret = PTR_ERR(hh);
    + goto out;
    + }
    +
    + /* TODO: ADD SANITY CHECKS TO VERIFY VALIDITY OF VALUES */
    + cpu = get_cpu();
    + memcpy(thread->tls_array, hh + 1, size);
    + load_TLS(thread, cpu);
    + put_cpu();
    +
    + ckpt_hdr_put(ctx, hh);
    + }
    +
    + ret = 0;
    + out:
    + ckpt_hdr_put(ctx, h);
    + return ret;
    +}
    +
    +#ifndef CONFIG_X86_64
    +
    +static int load_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + struct thread_struct *thread = &t->thread;
    + struct pt_regs *regs = task_pt_regs(t);
    +
    + /* TODO: ADD SANITY CHECKS TO VERIFY VALIDITY OF VALUES */
    + regs->bx = h->bx;
    + regs->cx = h->cx;
    + regs->dx = h->dx;
    + regs->si = h->si;
    + regs->di = h->di;
    + regs->bp = h->bp;
    + regs->ax = h->ax;
    + regs->ds = h->ds;
    + regs->es = h->es;
    + regs->orig_ax = h->orig_ax;
    + regs->ip = h->ip;
    + regs->cs = h->cs;
    + regs->flags = h->flags;
    + regs->sp = h->sp;
    + regs->ss = h->ss;
    +
    + thread->gs = h->gs;
    + thread->fs = h->fs;
    + loadsegment(gs, h->gs);
    + loadsegment(fs, h->fs);
    +
    + return 0;
    +}
    +
    +static int load_cpu_debug(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + /* TODO: ADD SANITY CHECKS TO VERIFY VALIDITY OF VALUES */
    + if (h->uses_debug) {
    + set_debugreg(h->debugreg0, 0);
    + set_debugreg(h->debugreg1, 1);
    + /* ignore 4, 5 */
    + set_debugreg(h->debugreg2, 2);
    + set_debugreg(h->debugreg3, 3);
    + set_debugreg(h->debugreg6, 6);
    + set_debugreg(h->debugreg7, 7);
    + }
    +
    + return 0;
    +}
    +
    +static int load_cpu_fpu(struct ckpt_hdr_cpu *h, struct task_struct *t)
    +{
    + preempt_disable();
    +
    + __clear_fpu(t); /* in case we used FPU in user mode */
    +
    + if (!h->used_math)
    + clear_used_math();
    +
    + preempt_enable();
    + return 0;
    +}
    +
    +static int restore_cpu_fpu(struct ckpt_ctx *ctx, struct task_struct *t)
    +{
    + struct ckpt_hdr *h;
    + int ret;
    +
    + /* init_fpu() eventually also calls set_used_math() */
    + ret = init_fpu(current);
    + if (ret < 0)
    + return ret;
    +
    + h = ckpt_read_obj_type(ctx, xstate_size + sizeof(*h),
    + CKPT_HDR_CPU_FPU);
    + if (IS_ERR(h))
    + return PTR_ERR(h);
    +
    + memcpy(t->thread.xstate, h + 1, xstate_size);
    +
    + ckpt_hdr_put(ctx, h);
    + return ret;
    +}
    +
    +#endif /* !CONFIG_X86_64 */
    +
    +/* read the cpu state and registers for the current task */
    +int restore_cpu(struct ckpt_ctx *ctx)
    +{
    + struct ckpt_hdr_cpu *h;
    + struct task_struct *t = current;
    + int ret;
    +
    + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_CPU);
    + if (IS_ERR(h))
    + return PTR_ERR(h);
    +
    + ckpt_debug("math %d debug %d\n", h->used_math, h->uses_debug);
    +
    + ret = load_cpu_regs(h, t);
    + if (ret < 0)
    + goto out;
    + ret = load_cpu_debug(h, t);
    + if (ret < 0)
    + goto out;
    + ret = load_cpu_fpu(h, t);
    + if (ret < 0)
    + goto out;
    +
    + if (h->used_math)
    + ret = restore_cpu_fpu(ctx, t);
    + out:
    + ckpt_hdr_put(ctx, h);
    + return ret;
    +}
    +
    +int restore_read_header_arch(struct ckpt_ctx *ctx)
    +{
    + struct ckpt_hdr_header_arch *h;
    + int ret = 0;
    +
    + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_HEADER_ARCH);
    + if (IS_ERR(h))
    + return PTR_ERR(h);
    +
    + /* FIX: verify compatibility of architecture features */
    +
    + /* verify FPU capabilities */
    + if (h->has_fxsr != cpu_has_fxsr ||
    + h->has_xsave != cpu_has_xsave ||
    + h->xstate_size != xstate_size)
    + ret = -EINVAL;
    +
    + ckpt_hdr_put(ctx, h);
    + return ret;
    +}
    diff --git a/checkpoint/checkpoint.c b/checkpoint/checkpoint.c
    index 56b690a..409c78b 100644
    --- a/checkpoint/checkpoint.c
    +++ b/checkpoint/checkpoint.c
    @@ -190,6 +190,8 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
    do_gettimeofday(&ktv);
    uts = utsname();

    + h->arch_id = cpu_to_le16(CKPT_ARCH_ID); /* see asm/checkpoitn.h */
    +
    h->magic = CHECKPOINT_MAGIC_HEAD;
    h->major = (LINUX_VERSION_CODE >> 16) & 0xff;
    h->minor = (LINUX_VERSION_CODE >> 8) & 0xff;
    @@ -219,7 +221,10 @@ static int checkpoint_write_header(struct ckpt_ctx *ctx)
    ret = ckpt_write_buffer(ctx, uts->machine, sizeof(uts->machine));
    up:
    up_read(&uts_sem);
    - return ret;
    + if (ret < 0)
    + return ret;
    +
    + return checkpoint_write_header_arch(ctx);
    }

    /* write the checkpoint trailer */
    diff --git a/checkpoint/process.c b/checkpoint/process.c
    index c2b7564..6cab717 100644
    --- a/checkpoint/process.c
    +++ b/checkpoint/process.c
    @@ -53,7 +53,15 @@ int checkpoint_task(struct ckpt_ctx *ctx, struct task_struct *t)

    ret = checkpoint_task_struct(ctx, t);
    ckpt_debug("task %d\n", ret);
    -
    + if (ret < 0)
    + goto out;
    + ret = checkpoint_thread(ctx, t);
    + ckpt_debug("thread %d\n", ret);
    + if (ret < 0)
    + goto out;
    + ret = checkpoint_cpu(ctx, t);
    + ckpt_debug("cpu %d\n", ret);
    + out:
    return ret;
    }

    @@ -92,6 +100,14 @@ int restore_task(struct ckpt_ctx *ctx)

    ret = restore_task_struct(ctx);
    ckpt_debug("task %d\n", ret);
    -
    + if (ret < 0)
    + goto out;
    + ret = restore_thread(ctx);
    + ckpt_debug("thread %d\n", ret);
    + if (ret < 0)
    + goto out;
    + ret = restore_cpu(ctx);
    + ckpt_debug("cpu %d\n", ret);
    + out:
    return ret;
    }
    diff --git a/checkpoint/restart.c b/checkpoint/restart.c
    index a6f73d3..e839538 100644
    --- a/checkpoint/restart.c
    +++ b/checkpoint/restart.c
    @@ -248,6 +248,8 @@ static int restore_read_header(struct ckpt_ctx *ctx)
    return PTR_ERR(h);

    ret = -EINVAL;
    + if (le16_to_cpu(h->arch_id) != CKPT_ARCH_ID)
    + goto out;
    if (h->magic != CHECKPOINT_MAGIC_HEAD ||
    h->rev != CHECKPOINT_VERSION ||
    h->major != ((LINUX_VERSION_CODE >> 16) & 0xff) ||
    @@ -276,6 +278,10 @@ static int restore_read_header(struct ckpt_ctx *ctx)
    if (ret < 0)
    goto out;
    ret = _ckpt_read_buffer(ctx, uts->machine, sizeof(uts->machine));
    + if (ret < 0)
    + goto out;
    +
    + ret = restore_read_header_arch(ctx);
    out:
    kfree(uts);
    ckpt_hdr_put(ctx, h);
    diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
    index 14da928..6247114 100644
    --- a/include/linux/checkpoint.h
    +++ b/include/linux/checkpoint.h
    @@ -12,6 +12,7 @@

    #include <linux/checkpoint_types.h>
    #include <linux/checkpoint_hdr.h>
    +#include <asm/checkpoint_hdr.h>

    extern int ckpt_kwrite(struct ckpt_ctx *ctx, void *buf, int count);
    extern int ckpt_kread(struct ckpt_ctx *ctx, void *buf, int count);
    @@ -43,6 +44,15 @@ extern int do_restart(struct ckpt_ctx *ctx, pid_t pid);
    extern int checkpoint_task(struct ckpt_ctx *ctx, struct task_struct *t);
    extern int restore_task(struct ckpt_ctx *ctx);

    +/* arch hooks */
    +extern int checkpoint_write_header_arch(struct ckpt_ctx *ctx);
    +extern int checkpoint_thread(struct ckpt_ctx *ctx, struct task_struct *t);
    +extern int checkpoint_cpu(struct ckpt_ctx *ctx, struct task_struct *t);
    +
    +extern int restore_read_header_arch(struct ckpt_ctx *ctx);
    +extern int restore_thread(struct ckpt_ctx *ctx);
    +extern int restore_cpu(struct ckpt_ctx *ctx);
    +

    /* debugging flags */
    #define CKPT_DBASE 0x1 /* anything */
    diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
    index c9a1653..a0c576c 100644
    --- a/include/linux/checkpoint_hdr.h
    +++ b/include/linux/checkpoint_hdr.h
    @@ -41,22 +41,32 @@ struct ckpt_hdr {
    /* header types */
    enum {
    CKPT_HDR_HEADER = 1,
    + CKPT_HDR_HEADER_ARCH,
    CKPT_HDR_BUFFER,
    CKPT_HDR_STRING,

    CKPT_HDR_TASK = 101,
    + CKPT_HDR_THREAD,
    + CKPT_HDR_CPU,
    +
    + /* 201-299: reserved for arch-dependent */

    CKPT_HDR_TAIL = 9001,

    CKPT_HDR_ERROR = 9999,
    };

    +/* architecture */
    +enum {
    + CKPT_ARCH_X86_32 = 1,
    +};
    +
    /* checkpoint image header */
    struct ckpt_hdr_header {
    struct ckpt_hdr h;
    __u64 magic;

    - __u16 _padding;
    + __u16 arch_id;

    __u16 major;
    __u16 minor;
    --
    1.6.0.4


    \
     
     \ /
      Last update: 2009-05-27 20:41    [W:0.068 / U:93.108 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site