Subject: + x86-export-x86-boot_params-to-sysfs.patch added to -mm tree To: dyoung@xxxxxxxxxx,James.Bottomley@xxxxxxxxxxxxxxxxxxxxx,bp@xxxxxxx,ebiederm@xxxxxxxxxxxx,greg@xxxxxxxxx,horms@xxxxxxxxxxxx,hpa@xxxxxxxxx,matt@xxxxxxxxxxxxxxxxx,mingo@xxxxxxx,mjg59@xxxxxxxxxxxxx,tglx@xxxxxxxxxxxxx,toshi.kani@xxxxxx,vgoyal@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 10 Dec 2013 15:23:26 -0800 The patch titled Subject: x86: export x86 boot_params to sysfs has been added to the -mm tree. Its filename is x86-export-x86-boot_params-to-sysfs.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/x86-export-x86-boot_params-to-sysfs.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/x86-export-x86-boot_params-to-sysfs.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Dave Young <dyoung@xxxxxxxxxx> Subject: x86: export x86 boot_params to sysfs kexec-tools use boot_params for getting the 1st kernel hardware_subarch, the kexec kernel efi runtime support also need read the old efi_info from boot_params. Currently it exists in debugfs which is not a good place for such infomation. Per HPA, we should avoid of "sploit debugfs". In this patch /sys/kernel/boot_params are exported, also the setup_data is exported as a subdirectory. kexec-tools is using debugfs for hardware_subarch for a long time now so we're not removing it yet. Structure is like below: /sys/kernel/boot_params |__ data /* boot_params in binary*/ |__ setup_data | |__ 0 /* the first setup_data node */ | | |__ data /* setup_data node 0 in binary*/ | | |__ type /* setup_data type of setup_data node 0, hex string */ [snip] |__ version /* boot protocal version (in hex, "0x" prefixed)*/ Signed-off-by: Dave Young <dyoung@xxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Greg KH <greg@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxx> Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx> Cc: Simon Horman <horms@xxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Toshi Kani <toshi.kani@xxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/ABI/testing/sysfs-kernel-boot_params | 39 + arch/x86/kernel/Makefile | 1 arch/x86/kernel/ksysfs.c | 339 +++++++++++ 3 files changed, 379 insertions(+) diff -puN /dev/null Documentation/ABI/testing/sysfs-kernel-boot_params --- /dev/null +++ a/Documentation/ABI/testing/sysfs-kernel-boot_params @@ -0,0 +1,39 @@ +What: /sys/kernel/boot_params +Date: December 2013 +Contact: Dave Young <dyoung@xxxxxxxxxx> +Description: + The /sys/kernel/boot_params directory contains two + files: "data" and "version" and one subdirectory "setup_data". + It is used to export the kernel boot parameters of an x86 + platform to userspace for kexec and debugging purpose. + + If there's no setup_data in boot_params the subdirectory will + not be created. + + "data" file is the binary representation of struct boot_params. + + "version" file is the string representation of boot + protocol version. + + "setup_data" subdirectory contains the setup_data data + structure in boot_params. setup_data is maintained in kernel + as a link list. In "setup_data" subdirectory there's one + subdirectory for each link list node named with the number + of the list nodes. The list node subdirectory contains two + files "type" and "data". "type" file is the string + representation of setup_data type. "data" file is the binary + representation of setup_data payload. + + The whole boot_params directory structure is like below: + /sys/kernel/boot_params + |__ data + |__ setup_data + | |__ 0 + | | |__ data + | | |__ type + | |__ 1 + | |__ data + | |__ type + |__ version + +Users: Kexec diff -puN arch/x86/kernel/Makefile~x86-export-x86-boot_params-to-sysfs arch/x86/kernel/Makefile --- a/arch/x86/kernel/Makefile~x86-export-x86-boot_params-to-sysfs +++ a/arch/x86/kernel/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_X86_64) += sys_x86_64.o x86 obj-y += syscall_$(BITS).o obj-$(CONFIG_X86_64) += vsyscall_64.o obj-$(CONFIG_X86_64) += vsyscall_emu_64.o +obj-$(CONFIG_SYSFS) += ksysfs.o obj-y += bootflag.o e820.o obj-y += pci-dma.o quirks.o topology.o kdebugfs.o obj-y += alternative.o i8253.o pci-nommu.o hw_breakpoint.o diff -puN /dev/null arch/x86/kernel/ksysfs.c --- /dev/null +++ a/arch/x86/kernel/ksysfs.c @@ -0,0 +1,339 @@ +/* + * Architecture specific sysfs attributes in /sys/kernel + * + * Copyright (C) 2007, Intel Corp. + * Huang Ying <ying.huang@xxxxxxxxx> + * Copyright (C) 2013, 2013 Red Hat, Inc. + * Dave Young <dyoung@xxxxxxxxxx> + * + * This file is released under the GPLv2 + */ + +#include <linux/kobject.h> +#include <linux/string.h> +#include <linux/sysfs.h> +#include <linux/init.h> +#include <linux/stat.h> +#include <linux/slab.h> +#include <linux/mm.h> + +#include <asm/setup.h> + +static ssize_t version_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "0x%04x\n", boot_params.hdr.version); +} + +static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version); + +static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + memcpy(buf, (void *)&boot_params + off, count); + return count; +} + +static struct bin_attribute boot_params_data_attr = { + .attr = { + .name = "data", + .mode = S_IRUGO, + }, + .read = boot_params_data_read, + .size = sizeof(boot_params), +}; + +static struct attribute *boot_params_version_attrs[] = { + &boot_params_version_attr.attr, + NULL, +}; + +static struct bin_attribute *boot_params_data_attrs[] = { + &boot_params_data_attr, + NULL, +}; + +static struct attribute_group boot_params_attr_group = { + .attrs = boot_params_version_attrs, + .bin_attrs = boot_params_data_attrs, +}; + +static int kobj_to_setup_data_nr(struct kobject *kobj, int *nr) +{ + const char *name; + + name = kobject_name(kobj); + return kstrtoint(name, 10, nr); +} + +static int get_setup_data_paddr(int nr, u64 *paddr) +{ + int i = 0; + struct setup_data *data; + u64 pa_data = boot_params.hdr.setup_data; + + while (pa_data) { + if (nr == i) { + *paddr = pa_data; + return 0; + } + data = ioremap_cache(pa_data, sizeof(*data)); + if (!data) + return -ENOMEM; + + pa_data = data->next; + iounmap(data); + i++; + } + return -EINVAL; +} + +static int __init get_setup_data_size(int nr, size_t *size) +{ + int i = 0; + struct setup_data *data; + u64 pa_data = boot_params.hdr.setup_data; + + while (pa_data) { + data = ioremap_cache(pa_data, sizeof(*data)); + if (!data) + return -ENOMEM; + if (nr == i) { + *size = data->len; + iounmap(data); + return 0; + } + + pa_data = data->next; + iounmap(data); + i++; + } + return -EINVAL; +} + +static ssize_t type_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + int nr, ret; + u64 paddr; + struct setup_data *data; + + ret = kobj_to_setup_data_nr(kobj, &nr); + if (ret) + return ret; + + ret = get_setup_data_paddr(nr, &paddr); + if (ret) + return ret; + data = ioremap_cache(paddr, sizeof(*data)); + if (!data) + return -ENOMEM; + + ret = sprintf(buf, "0x%x\n", data->type); + iounmap(data); + return ret; +} + +static ssize_t setup_data_data_read(struct file *fp, + struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, + loff_t off, size_t count) +{ + int nr, ret = 0; + u64 paddr; + struct setup_data *data; + void *p; + + ret = kobj_to_setup_data_nr(kobj, &nr); + if (ret) + return ret; + + ret = get_setup_data_paddr(nr, &paddr); + if (ret) + return ret; + data = ioremap_cache(paddr, sizeof(*data)); + if (!data) + return -ENOMEM; + + if (off > data->len) { + ret = -EINVAL; + goto out; + } + + if (count > data->len - off) + count = data->len - off; + + if (!count) + goto out; + + ret = count; + p = ioremap_cache(paddr + sizeof(*data), data->len); + if (!p) { + ret = -ENOMEM; + goto out; + } + memcpy(buf, p + off, count); + iounmap(p); +out: + iounmap(data); + return ret; +} + +static struct kobj_attribute type_attr = __ATTR_RO(type); + +static struct bin_attribute data_attr = { + .attr = { + .name = "data", + .mode = S_IRUGO, + }, + .read = setup_data_data_read, +}; + +static struct attribute *setup_data_type_attrs[] = { + &type_attr.attr, + NULL, +}; + +static struct bin_attribute *setup_data_data_attrs[] = { + &data_attr, + NULL, +}; + +static struct attribute_group setup_data_attr_group = { + .attrs = setup_data_type_attrs, + .bin_attrs = setup_data_data_attrs, +}; + +static int __init create_setup_data_node(struct kobject *parent, + struct kobject **kobjp, int nr) +{ + int ret = 0; + size_t size; + struct kobject *kobj; + char name[16]; /* should be enough for setup_data nodes numbers */ + snprintf(name, 16, "%d", nr); + + kobj = kobject_create_and_add(name, parent); + if (!kobj) + return -ENOMEM; + + ret = get_setup_data_size(nr, &size); + if (ret) + goto out_kobj; + + data_attr.size = size; + ret = sysfs_create_group(kobj, &setup_data_attr_group); + if (ret) + goto out_kobj; + *kobjp = kobj; + + return 0; +out_kobj: + kobject_put(kobj); + return ret; +} + +static void __init cleanup_setup_data_node(struct kobject *kobj) +{ + sysfs_remove_group(kobj, &setup_data_attr_group); + kobject_put(kobj); +} + +static int __init get_setup_data_total_num(u64 pa_data, int *nr) +{ + int ret = 0; + struct setup_data *data; + + *nr = 0; + while (pa_data) { + *nr += 1; + data = ioremap_cache(pa_data, sizeof(*data)); + if (!data) { + ret = -ENOMEM; + goto out; + } + pa_data = data->next; + iounmap(data); + } + +out: + return ret; +} + +static int __init create_setup_data_nodes(struct kobject *parent) +{ + struct kobject *setup_data_kobj, **kobjp; + u64 pa_data; + int i, j, nr, ret = 0; + + pa_data = boot_params.hdr.setup_data; + if (!pa_data) + return 0; + + setup_data_kobj = kobject_create_and_add("setup_data", parent); + if (!setup_data_kobj) { + ret = -ENOMEM; + goto out; + } + + ret = get_setup_data_total_num(pa_data, &nr); + if (ret) + goto out_setup_data_kobj; + + kobjp = kmalloc(sizeof(*kobjp) * nr, GFP_KERNEL); + if (!kobjp) { + ret = -ENOMEM; + goto out_setup_data_kobj; + } + + for (i = 0; i < nr; i++) { + ret = create_setup_data_node(setup_data_kobj, kobjp + i, i); + if (ret) + goto out_clean_nodes; + } + + kfree(kobjp); + return 0; + +out_clean_nodes: + for (j = i - 1; j > 0; j--) + cleanup_setup_data_node(*(kobjp + j)); + kfree(kobjp); +out_setup_data_kobj: + kobject_put(setup_data_kobj); +out: + return ret; +} + +static int __init boot_params_ksysfs_init(void) +{ + int ret; + struct kobject *boot_params_kobj; + + boot_params_kobj = kobject_create_and_add("boot_params", + kernel_kobj); + if (!boot_params_kobj) { + ret = -ENOMEM; + goto out; + } + + ret = sysfs_create_group(boot_params_kobj, &boot_params_attr_group); + if (ret) + goto out_boot_params_kobj; + + ret = create_setup_data_nodes(boot_params_kobj); + if (ret) + goto out_create_group; + + return 0; +out_create_group: + sysfs_remove_group(boot_params_kobj, &boot_params_attr_group); +out_boot_params_kobj: + kobject_put(boot_params_kobj); +out: + return ret; +} + +arch_initcall(boot_params_ksysfs_init); _ Patches currently in -mm which might be from dyoung@xxxxxxxxxx are kexec-migrate-to-reboot-cpu.patch x86-mm-sparse-warning-fix-for-early_memremap.patch efi-use-early_memremap-and-early_memunmap.patch efi-remove-unused-variables-in-__map_region.patch efi-add-a-wrapper-function-efi_map_region_fixed.patch efi-reserve-boot-service-fix.patch efi-cleanup-efi_enter_virtual_mode-function.patch efi-export-more-efi-table-variable-to-sysfs.patch efi-export-efi-runtime-memory-mapping-to-sysfs.patch efi-pass-kexec-necessary-efi-data-via-setup_data.patch efi-only-print-saved-efi-runtime-maps-instead-of-all-memmap-ranges-for-kexec.patch x86-add-xloadflags-bit-for-efi-runtime-support-on-kexec.patch x86-export-x86-boot_params-to-sysfs.patch x86-reserve-setup_data-ranges-late-after-parsing-memmap-cmdline.patch x86-kdebugfs-do-not-use-__va-for-getting-setup_data-virt-addr.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html