The following commit has been merged into the x86/boot branch of tip: Commit-ID: b3c72fc9a78e74161f9d05ef7191706060628f8c Gitweb: https://git.kernel.org/tip/b3c72fc9a78e74161f9d05ef7191706060628f8c Author: Daniel Kiper <daniel.kiper@xxxxxxxxxx> AuthorDate: Tue, 12 Nov 2019 14:46:40 +01:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Tue, 12 Nov 2019 16:21:15 +01:00 x86/boot: Introduce setup_indirect The setup_data is a bit awkward to use for extremely large data objects, both because the setup_data header has to be adjacent to the data object and because it has a 32-bit length field. However, it is important that intermediate stages of the boot process have a way to identify which chunks of memory are occupied by kernel data. Thus introduce an uniform way to specify such indirect data as setup_indirect struct and SETUP_INDIRECT type. And finally bump setup_header version in arch/x86/boot/header.S. Suggested-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Ross Philipson <ross.philipson@xxxxxxxxxx> Reviewed-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: ard.biesheuvel@xxxxxxxxxx Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: dave.hansen@xxxxxxxxxxxxxxx Cc: eric.snowberg@xxxxxxxxxx Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: kanth.ghatraju@xxxxxxxxxx Cc: linux-doc@xxxxxxxxxxxxxxx Cc: linux-efi <linux-efi@xxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: rdunlap@xxxxxxxxxxxxx Cc: ross.philipson@xxxxxxxxxx Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: x86-ml <x86@xxxxxxxxxx> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx Link: https://lkml.kernel.org/r/20191112134640.16035-4-daniel.kiper@xxxxxxxxxx --- Documentation/x86/boot.rst | 43 ++++++++++++++++++++++++- arch/x86/boot/compressed/kaslr.c | 12 +++++++- arch/x86/boot/compressed/kernel_info.S | 2 +- arch/x86/boot/header.S | 2 +- arch/x86/include/uapi/asm/bootparam.h | 16 +++++++-- arch/x86/kernel/e820.c | 11 ++++++- arch/x86/kernel/kdebugfs.c | 21 +++++++++--- arch/x86/kernel/ksysfs.c | 31 +++++++++++++----- arch/x86/kernel/setup.c | 6 +++- arch/x86/mm/ioremap.c | 11 ++++++- 10 files changed, 138 insertions(+), 17 deletions(-) diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst index 6cdd767..90bb8f5 100644 --- a/Documentation/x86/boot.rst +++ b/Documentation/x86/boot.rst @@ -827,6 +827,47 @@ Protocol: 2.09+ sure to consider the case where the linked list already contains entries. + The setup_data is a bit awkward to use for extremely large data objects, + both because the setup_data header has to be adjacent to the data object + and because it has a 32-bit length field. However, it is important that + intermediate stages of the boot process have a way to identify which + chunks of memory are occupied by kernel data. + + Thus setup_indirect struct and SETUP_INDIRECT type were introduced in + protocol 2.15. + + struct setup_indirect { + __u32 type; + __u32 reserved; /* Reserved, must be set to zero. */ + __u64 len; + __u64 addr; + }; + + The type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be + SETUP_INDIRECT itself since making the setup_indirect a tree structure + could require a lot of stack space in something that needs to parse it + and stack space can be limited in boot contexts. + + Let's give an example how to point to SETUP_E820_EXT data using setup_indirect. + In this case setup_data and setup_indirect will look like this: + + struct setup_data { + __u64 next = 0 or <addr_of_next_setup_data_struct>; + __u32 type = SETUP_INDIRECT; + __u32 len = sizeof(setup_data); + __u8 data[sizeof(setup_indirect)] = struct setup_indirect { + __u32 type = SETUP_INDIRECT | SETUP_E820_EXT; + __u32 reserved = 0; + __u64 len = <len_of_SETUP_E820_EXT_data>; + __u64 addr = <addr_of_SETUP_E820_EXT_data>; + } + } + +.. note:: + SETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished + from SETUP_INDIRECT itself. So, this kind of objects cannot be provided + by the bootloaders. + ============ ============ Field name: pref_address Type: read (reloc) @@ -986,7 +1027,7 @@ Field name: setup_type_max Offset/size: 0x000c/4 ============ ============== - This field contains maximal allowed type for setup_data. + This field contains maximal allowed type for setup_data and setup_indirect structs. The Image Checksum diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 2e53c05..bb9bfef 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -459,6 +459,18 @@ static bool mem_avoid_overlap(struct mem_vector *img, is_overlapping = true; } + if (ptr->type == SETUP_INDIRECT && + ((struct setup_indirect *)ptr->data)->type != SETUP_INDIRECT) { + avoid.start = ((struct setup_indirect *)ptr->data)->addr; + avoid.size = ((struct setup_indirect *)ptr->data)->len; + + if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) { + *overlap = avoid; + earliest = overlap->start; + is_overlapping = true; + } + } + ptr = (struct setup_data *)(unsigned long)ptr->next; } diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S index 018dacb..f818ee8 100644 --- a/arch/x86/boot/compressed/kernel_info.S +++ b/arch/x86/boot/compressed/kernel_info.S @@ -14,7 +14,7 @@ kernel_info: /* Size total. */ .long kernel_info_end - kernel_info - /* Maximal allowed type for setup_data. */ + /* Maximal allowed type for setup_data and setup_indirect structs. */ .long SETUP_TYPE_MAX kernel_info_var_len_data: diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index 22dceca..97d9b6d 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -300,7 +300,7 @@ _start: # Part 2 of the header, from the old setup.S .ascii "HdrS" # header signature - .word 0x020d # header version number (>= 0x0105) + .word 0x020f # header version number (>= 0x0105) # or else old loadlin-1.5 will fail) .globl realmode_swtch realmode_swtch: .word 0, 0 # default_switch, SETUPSEG diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index dbb4112..949066b 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -2,7 +2,7 @@ #ifndef _ASM_X86_BOOTPARAM_H #define _ASM_X86_BOOTPARAM_H -/* setup_data types */ +/* setup_data/setup_indirect types */ #define SETUP_NONE 0 #define SETUP_E820_EXT 1 #define SETUP_DTB 2 @@ -11,8 +11,10 @@ #define SETUP_APPLE_PROPERTIES 5 #define SETUP_JAILHOUSE 6 -/* max(SETUP_*) */ -#define SETUP_TYPE_MAX SETUP_JAILHOUSE +#define SETUP_INDIRECT (1<<31) + +/* SETUP_INDIRECT | max(SETUP_*) */ +#define SETUP_TYPE_MAX (SETUP_INDIRECT | SETUP_JAILHOUSE) /* ram_size flags */ #define RAMDISK_IMAGE_START_MASK 0x07FF @@ -52,6 +54,14 @@ struct setup_data { __u8 data[0]; }; +/* extensible setup indirect data node */ +struct setup_indirect { + __u32 type; + __u32 reserved; /* Reserved, must be set to zero. */ + __u64 len; + __u64 addr; +}; + struct setup_header { __u8 setup_sects; __u16 root_flags; diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 7da2bcd..0bfe9a6 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -999,6 +999,17 @@ void __init e820__reserve_setup_data(void) data = early_memremap(pa_data, sizeof(*data)); e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); + + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + e820__range_update(((struct setup_indirect *)data->data)->addr, + ((struct setup_indirect *)data->data)->len, + E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); + e820__range_update_kexec(((struct setup_indirect *)data->data)->addr, + ((struct setup_indirect *)data->data)->len, + E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); + } + pa_data = data->next; early_memunmap(data, sizeof(*data)); } diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c index edaa30b..64b6da9 100644 --- a/arch/x86/kernel/kdebugfs.c +++ b/arch/x86/kernel/kdebugfs.c @@ -44,7 +44,12 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf, if (count > node->len - pos) count = node->len - pos; - pa = node->paddr + sizeof(struct setup_data) + pos; + pa = node->paddr + pos; + + /* Is it direct data or invalid indirect one? */ + if (!(node->type & SETUP_INDIRECT) || node->type == SETUP_INDIRECT) + pa += sizeof(struct setup_data); + p = memremap(pa, count, MEMREMAP_WB); if (!p) return -ENOMEM; @@ -108,9 +113,17 @@ static int __init create_setup_data_nodes(struct dentry *parent) goto err_dir; } - node->paddr = pa_data; - node->type = data->type; - node->len = data->len; + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + node->paddr = ((struct setup_indirect *)data->data)->addr; + node->type = ((struct setup_indirect *)data->data)->type; + node->len = ((struct setup_indirect *)data->data)->len; + } else { + node->paddr = pa_data; + node->type = data->type; + node->len = data->len; + } + create_setup_data_node(d, no, node); pa_data = data->next; diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c index 7969da9..d0a1912 100644 --- a/arch/x86/kernel/ksysfs.c +++ b/arch/x86/kernel/ksysfs.c @@ -100,7 +100,12 @@ static int __init get_setup_data_size(int nr, size_t *size) if (!data) return -ENOMEM; if (nr == i) { - *size = data->len; + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) + *size = ((struct setup_indirect *)data->data)->len; + else + *size = data->len; + memunmap(data); return 0; } @@ -130,7 +135,10 @@ static ssize_t type_show(struct kobject *kobj, if (!data) return -ENOMEM; - ret = sprintf(buf, "0x%x\n", data->type); + if (data->type == SETUP_INDIRECT) + ret = sprintf(buf, "0x%x\n", ((struct setup_indirect *)data->data)->type); + else + ret = sprintf(buf, "0x%x\n", data->type); memunmap(data); return ret; } @@ -142,7 +150,7 @@ static ssize_t setup_data_data_read(struct file *fp, loff_t off, size_t count) { int nr, ret = 0; - u64 paddr; + u64 paddr, len; struct setup_data *data; void *p; @@ -157,19 +165,28 @@ static ssize_t setup_data_data_read(struct file *fp, if (!data) return -ENOMEM; - if (off > data->len) { + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + paddr = ((struct setup_indirect *)data->data)->addr; + len = ((struct setup_indirect *)data->data)->len; + } else { + paddr += sizeof(*data); + len = data->len; + } + + if (off > len) { ret = -EINVAL; goto out; } - if (count > data->len - off) - count = data->len - off; + if (count > len - off) + count = len - off; if (!count) goto out; ret = count; - p = memremap(paddr + sizeof(*data), data->len, MEMREMAP_WB); + p = memremap(paddr, len, MEMREMAP_WB); if (!p) { ret = -ENOMEM; goto out; diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 77ea96b..8f48bb8 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -438,6 +438,12 @@ static void __init memblock_x86_reserve_range_setup_data(void) while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); memblock_reserve(pa_data, sizeof(*data) + data->len); + + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) + memblock_reserve(((struct setup_indirect *)data->data)->addr, + ((struct setup_indirect *)data->data)->len); + pa_data = data->next; early_memunmap(data, sizeof(*data)); } diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index a39dcdb..1ff9c20 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -626,6 +626,17 @@ static bool memremap_is_setup_data(resource_size_t phys_addr, paddr_next = data->next; len = data->len; + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) { + memunmap(data); + return true; + } + + if (data->type == SETUP_INDIRECT && + ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + paddr = ((struct setup_indirect *)data->data)->addr; + len = ((struct setup_indirect *)data->data)->len; + } + memunmap(data); if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
