diff options
| -rw-r--r-- | fs/proc/Kconfig | 15 | ||||
| -rw-r--r-- | fs/proc/vmcore.c | 135 | ||||
| -rw-r--r-- | include/linux/crash_dump.h | 18 | ||||
| -rw-r--r-- | include/linux/kcore.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/elf.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/vmcore.h | 18 |
6 files changed, 184 insertions, 9 deletions
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index 1ade1206bb89..0eaeb41453f5 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -43,6 +43,21 @@ config PROC_VMCORE help Exports the dump image of crashed kernel in ELF format. +config PROC_VMCORE_DEVICE_DUMP + bool "Device Hardware/Firmware Log Collection" + depends on PROC_VMCORE + default n + help + After kernel panic, device drivers can collect the device + specific snapshot of their hardware or firmware before the + underlying devices are initialized in crash recovery kernel. + Note that the device driver must be present in the crash + recovery kernel's initramfs to collect its underlying device + snapshot. + + If you say Y here, the collected device dumps will be added + as ELF notes to /proc/vmcore. + config PROC_SYSCTL bool "Sysctl support (/proc/sys)" if EXPERT depends on PROC_FS diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index a45f0af22a60..abb3dba0fa49 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -20,6 +20,7 @@ #include <linux/init.h> #include <linux/crash_dump.h> #include <linux/list.h> +#include <linux/mutex.h> #include <linux/vmalloc.h> #include <linux/pagemap.h> #include <linux/uaccess.h> @@ -44,6 +45,12 @@ static u64 vmcore_size; static struct proc_dir_entry *proc_vmcore; +#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP +/* Device Dump list and mutex to synchronize access to list */ +static LIST_HEAD(vmcoredd_list); +static DEFINE_MUTEX(vmcoredd_mutex); +#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ + /* * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error * The called function has to take care of module refcounting. @@ -302,10 +309,8 @@ static const struct vm_operations_struct vmcore_mmap_ops = { }; /** - * alloc_elfnotes_buf - allocate buffer for ELF note segment in - * vmalloc memory - * - * @notes_sz: size of buffer + * vmcore_alloc_buf - allocate buffer in vmalloc memory + * @sizez: size of buffer * * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap * the buffer to user-space by means of remap_vmalloc_range(). @@ -313,12 +318,12 @@ static const struct vm_operations_struct vmcore_mmap_ops = { * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is * disabled and there's no need to allow users to mmap the buffer. */ -static inline char *alloc_elfnotes_buf(size_t notes_sz) +static inline char *vmcore_alloc_buf(size_t size) { #ifdef CONFIG_MMU - return vmalloc_user(notes_sz); + return vmalloc_user(size); #else - return vzalloc(notes_sz); + return vzalloc(size); #endif } @@ -665,7 +670,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, return rc; *notes_sz = roundup(phdr_sz, PAGE_SIZE); - *notes_buf = alloc_elfnotes_buf(*notes_sz); + *notes_buf = vmcore_alloc_buf(*notes_sz); if (!*notes_buf) return -ENOMEM; @@ -851,7 +856,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, return rc; *notes_sz = roundup(phdr_sz, PAGE_SIZE); - *notes_buf = alloc_elfnotes_buf(*notes_sz); + *notes_buf = vmcore_alloc_buf(*notes_sz); if (!*notes_buf) return -ENOMEM; @@ -1145,6 +1150,115 @@ static int __init parse_crash_elf_headers(void) return 0; } +#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP +/** + * vmcoredd_write_header - Write vmcore device dump header at the + * beginning of the dump's buffer. + * @buf: Output buffer where the note is written + * @data: Dump info + * @size: Size of the dump + * + * Fills beginning of the dump's buffer with vmcore device dump header. + */ +static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, + u32 size) +{ + struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf; + + vdd_hdr->n_namesz = sizeof(vdd_hdr->name); + vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name); + vdd_hdr->n_type = NT_VMCOREDD; + + strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME, + sizeof(vdd_hdr->name)); + memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name)); +} + +/** + * vmcore_add_device_dump - Add a buffer containing device dump to vmcore + * @data: dump info. + * + * Allocate a buffer and invoke the calling driver's dump collect routine. + * Write Elf note at the beginning of the buffer to indicate vmcore device + * dump and add the dump to global list. + */ +int vmcore_add_device_dump(struct vmcoredd_data *data) +{ + struct vmcoredd_node *dump; + void *buf = NULL; + size_t data_size; + int ret; + + if (!data || !strlen(data->dump_name) || + !data->vmcoredd_callback || !data->size) + return -EINVAL; + + dump = vzalloc(sizeof(*dump)); + if (!dump) { + ret = -ENOMEM; + goto out_err; + } + + /* Keep size of the buffer page aligned so that it can be mmaped */ + data_size = roundup(sizeof(struct vmcoredd_header) + data->size, + PAGE_SIZE); + + /* Allocate buffer for driver's to write their dumps */ + buf = vmcore_alloc_buf(data_size); + if (!buf) { + ret = -ENOMEM; + goto out_err; + } + + vmcoredd_write_header(buf, data, data_size - + sizeof(struct vmcoredd_header)); + + /* Invoke the driver's dump collection routing */ + ret = data->vmcoredd_callback(data, buf + + sizeof(struct vmcoredd_header)); + if (ret) + goto out_err; + + dump->buf = buf; + dump->size = data_size; + + /* Add the dump to driver sysfs list */ + mutex_lock(&vmcoredd_mutex); + list_add_tail(&dump->list, &vmcoredd_list); + mutex_unlock(&vmcoredd_mutex); + + return 0; + +out_err: + if (buf) + vfree(buf); + + if (dump) + vfree(dump); + + return ret; +} +EXPORT_SYMBOL(vmcore_add_device_dump); +#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ + +/* Free all dumps in vmcore device dump list */ +static void vmcore_free_device_dumps(void) +{ +#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP + mutex_lock(&vmcoredd_mutex); + while (!list_empty(&vmcoredd_list)) { + struct vmcoredd_node *dump; + + dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node, + list); + list_del(&dump->list); + vfree(dump->buf); + vfree(dump); + } + mutex_unlock(&vmcoredd_mutex); +#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ +} + /* Init function for vmcore module. */ static int __init vmcore_init(void) { @@ -1192,4 +1306,7 @@ void vmcore_cleanup(void) kfree(m); } free_elfcorebuf(); + + /* clear vmcore device dump list */ + vmcore_free_device_dumps(); } diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index f7ac2aa93269..3e4ba9d753c8 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -5,6 +5,7 @@ #include <linux/kexec.h> #include <linux/proc_fs.h> #include <linux/elf.h> +#include <uapi/linux/vmcore.h> #include <asm/pgtable.h> /* for pgprot_t */ @@ -93,4 +94,21 @@ static inline bool is_kdump_kernel(void) { return 0; } #endif /* CONFIG_CRASH_DUMP */ extern unsigned long saved_max_pfn; + +/* Device Dump information to be filled by drivers */ +struct vmcoredd_data { + char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */ + unsigned int size; /* Size of the dump */ + /* Driver's registered callback to be invoked to collect dump */ + int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf); +}; + +#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP +int vmcore_add_device_dump(struct vmcoredd_data *data); +#else +static inline int vmcore_add_device_dump(struct vmcoredd_data *data) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ #endif /* LINUX_CRASHDUMP_H */ diff --git a/include/linux/kcore.h b/include/linux/kcore.h index 80db19d3a505..8de55e4b5ee9 100644 --- a/include/linux/kcore.h +++ b/include/linux/kcore.h @@ -28,6 +28,12 @@ struct vmcore { loff_t offset; }; +struct vmcoredd_node { + struct list_head list; /* List of dumps */ + void *buf; /* Buffer containing device's dump */ + unsigned int size; /* Size of the buffer */ +}; + #ifdef CONFIG_PROC_KCORE extern void kclist_add(struct kcore_list *, void *, size_t, int type); #else diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index e2535d6dcec7..4e12c423b9fe 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -421,6 +421,7 @@ typedef struct elf64_shdr { #define NT_ARM_SYSTEM_CALL 0x404 /* ARM system call number */ #define NT_ARM_SVE 0x405 /* ARM Scalable Vector Extension registers */ #define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */ +#define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */ /* Note header in a PT_NOTE section */ typedef struct elf32_note { diff --git a/include/uapi/linux/vmcore.h b/include/uapi/linux/vmcore.h new file mode 100644 index 000000000000..022619668e0e --- /dev/null +++ b/include/uapi/linux/vmcore.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _UAPI_VMCORE_H +#define _UAPI_VMCORE_H + +#include <linux/types.h> + +#define VMCOREDD_NOTE_NAME "LINUX" +#define VMCOREDD_MAX_NAME_BYTES 44 + +struct vmcoredd_header { + __u32 n_namesz; /* Name size */ + __u32 n_descsz; /* Content size */ + __u32 n_type; /* NT_VMCOREDD */ + __u8 name[8]; /* LINUX\0\0\0 */ + __u8 dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Device dump's name */ +}; + +#endif /* _UAPI_VMCORE_H */ |