As documented, the setup_indirect structure is nested inside the setup_data structures in the setup_data list. The code was accessing the fields inside the setup_indirect structure but only the sizeof(struct setup_data) was being memremapped. No crash occured but this is just due to how the area was remapped under the covers.
The setup_indirect structure was introduced in commit: commit b3c72fc9a78e (x86/boot: Introduce setup_indirect) Signed-off-by: Ross Philipson <[email protected]> --- arch/x86/kernel/e820.c | 31 ++++++++++++++++--------- arch/x86/kernel/kdebugfs.c | 28 ++++++++++++++++------- arch/x86/kernel/ksysfs.c | 56 ++++++++++++++++++++++++++++++++++++---------- arch/x86/kernel/setup.c | 23 +++++++++++++------ arch/x86/mm/ioremap.c | 13 +++++++---- 5 files changed, 109 insertions(+), 42 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index bc0657f..e023950 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -996,7 +996,8 @@ static int __init parse_memmap_opt(char *str) void __init e820__reserve_setup_data(void) { struct setup_data *data; - u64 pa_data; + u64 pa_data, pa_next; + u32 len; pa_data = boot_params.hdr.setup_data; if (!pa_data) @@ -1004,6 +1005,9 @@ void __init e820__reserve_setup_data(void) while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); + len = sizeof(*data); + pa_next = data->next; + e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN); /* @@ -1015,18 +1019,23 @@ void __init e820__reserve_setup_data(void) 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); + if (data->type == SETUP_INDIRECT) { + len += data->len; + early_memunmap(data, sizeof(*data)); + data = early_memremap(pa_data, len); + + if (((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)); + pa_data = pa_next; + early_memunmap(data, len); } e820__update_table(e820_table); diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c index 64b6da9..2fa1b93 100644 --- a/arch/x86/kernel/kdebugfs.c +++ b/arch/x86/kernel/kdebugfs.c @@ -92,7 +92,8 @@ static int __init create_setup_data_nodes(struct dentry *parent) struct setup_data *data; int error; struct dentry *d; - u64 pa_data; + u64 pa_data, pa_next; + u32 len; int no = 0; d = debugfs_create_dir("setup_data", parent); @@ -112,12 +113,23 @@ static int __init create_setup_data_nodes(struct dentry *parent) error = -ENOMEM; goto err_dir; } - - 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; + pa_next = data->next; + + if (data->type == SETUP_INDIRECT) { + len = sizeof(*data) + data->len; + memunmap(data); + data = memremap(pa_data, len, MEMREMAP_WB); + if (!data) { + kfree(node); + error = -ENOMEM; + goto err_dir; + } + + if (((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; @@ -125,7 +137,7 @@ static int __init create_setup_data_nodes(struct dentry *parent) } create_setup_data_node(d, no, node); - pa_data = data->next; + pa_data = pa_next; memunmap(data); no++; diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c index d0a1912..4cef401 100644 --- a/arch/x86/kernel/ksysfs.c +++ b/arch/x86/kernel/ksysfs.c @@ -93,24 +93,35 @@ 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; + u64 pa_data = boot_params.hdr.setup_data, pa_next; + u32 len; while (pa_data) { data = memremap(pa_data, sizeof(*data), MEMREMAP_WB); if (!data) return -ENOMEM; + pa_next = data->next; + if (nr == i) { - if (data->type == SETUP_INDIRECT && - ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) - *size = ((struct setup_indirect *)data->data)->len; - else + if (data->type == SETUP_INDIRECT) { + len = sizeof(*data) + data->len; + memunmap(data); + data = memremap(pa_data, len, MEMREMAP_WB); + if (!data) + return -ENOMEM; + + if (((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) + *size = ((struct setup_indirect *)data->data)->len; + else + *size = data->len; + } else *size = data->len; memunmap(data); return 0; } - pa_data = data->next; + pa_data = pa_next; memunmap(data); i++; } @@ -122,6 +133,7 @@ static ssize_t type_show(struct kobject *kobj, { int nr, ret; u64 paddr; + u32 len; struct setup_data *data; ret = kobj_to_setup_data_nr(kobj, &nr); @@ -135,9 +147,14 @@ static ssize_t type_show(struct kobject *kobj, if (!data) return -ENOMEM; - if (data->type == SETUP_INDIRECT) + if (data->type == SETUP_INDIRECT) { + len = sizeof(*data) + data->len; + memunmap(data); + data = memremap(paddr, len, MEMREMAP_WB); + if (!data) + return -ENOMEM; ret = sprintf(buf, "0x%x\n", ((struct setup_indirect *)data->data)->type); - else + } else ret = sprintf(buf, "0x%x\n", data->type); memunmap(data); return ret; @@ -165,10 +182,25 @@ static ssize_t setup_data_data_read(struct file *fp, if (!data) return -ENOMEM; - 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; + if (data->type == SETUP_INDIRECT) { + len = sizeof(*data) + data->len; + memunmap(data); + data = memremap(paddr, len, MEMREMAP_WB); + if (!data) + return -ENOMEM; + + if (((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + paddr = ((struct setup_indirect *)data->data)->addr; + len = ((struct setup_indirect *)data->data)->len; + } else { + /* + * Even though this is technically undefined, return + * the data as though it is a normal setup_data struct. + * This will at least allow it to be inspected. + */ + paddr += sizeof(*data); + len = data->len; + } } else { paddr += sizeof(*data); len = data->len; diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index bff3a78..055a834 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -368,20 +368,29 @@ static void __init parse_setup_data(void) static void __init memblock_x86_reserve_range_setup_data(void) { struct setup_data *data; - u64 pa_data; + u64 pa_data, pa_next; + u32 len; pa_data = boot_params.hdr.setup_data; while (pa_data) { data = early_memremap(pa_data, sizeof(*data)); + len = sizeof(*data); + pa_next = data->next; + 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); + if (data->type == SETUP_INDIRECT) { + len += data->len; + early_memunmap(data, sizeof(*data)); + data = early_memremap(pa_data, len); - pa_data = data->next; - early_memunmap(data, sizeof(*data)); + if (((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) + memblock_reserve(((struct setup_indirect *)data->data)->addr, + ((struct setup_indirect *)data->data)->len); + } + + pa_data = pa_next; + early_memunmap(data, len); } } diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 60ade7d..ab74e4f 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -635,10 +635,15 @@ static bool memremap_is_setup_data(resource_size_t phys_addr, 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; + if (data->type == SETUP_INDIRECT) { + memunmap(data); + data = memremap(paddr, sizeof(*data) + len, + MEMREMAP_WB | MEMREMAP_DEC); + + if (((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) { + paddr = ((struct setup_indirect *)data->data)->addr; + len = ((struct setup_indirect *)data->data)->len; + } } memunmap(data); -- 1.8.3.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
