diff options
Diffstat (limited to 'fs/proc/vmcore.c')
| -rw-r--r-- | fs/proc/vmcore.c | 635 |
1 files changed, 408 insertions, 227 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 3fe90443c1bb..f188bd900eb2 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * fs/proc/vmcore.c Interface for accessing the crash * dump from the system's previous life. @@ -7,6 +8,8 @@ * */ +#define pr_fmt(fmt) "vmcore: " fmt + #include <linux/mm.h> #include <linux/kcore.h> #include <linux/user.h> @@ -20,12 +23,12 @@ #include <linux/init.h> #include <linux/crash_dump.h> #include <linux/list.h> +#include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/vmalloc.h> #include <linux/pagemap.h> -#include <linux/uaccess.h> -#include <linux/mem_encrypt.h> -#include <asm/pgtable.h> +#include <linux/uio.h> +#include <linux/cc_platform.h> #include <asm/io.h> #include "internal.h" @@ -50,62 +53,116 @@ static u64 vmcore_size; static struct proc_dir_entry *proc_vmcore; #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP +struct vmcoredd_node { + struct list_head list; /* List of dumps */ + void *buf; /* Buffer containing device's dump */ + unsigned int size; /* Size of the buffer */ +}; + /* Device Dump list and mutex to synchronize access to list */ static LIST_HEAD(vmcoredd_list); -static DEFINE_MUTEX(vmcoredd_mutex); + +static bool vmcoredd_disabled; +core_param(novmcoredd, vmcoredd_disabled, bool, 0); #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ /* Device Dump Size */ static size_t vmcoredd_orig_sz; -/* - * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error - * The called function has to take care of module refcounting. - */ -static int (*oldmem_pfn_is_ram)(unsigned long pfn); +static DEFINE_MUTEX(vmcore_mutex); + +DEFINE_STATIC_SRCU(vmcore_cb_srcu); +/* List of registered vmcore callbacks. */ +static LIST_HEAD(vmcore_cb_list); +/* Whether the vmcore has been opened once. */ +static bool vmcore_opened; +/* Whether the vmcore is currently open. */ +static unsigned int vmcore_open; -int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)) +static void vmcore_process_device_ram(struct vmcore_cb *cb); + +void register_vmcore_cb(struct vmcore_cb *cb) { - if (oldmem_pfn_is_ram) - return -EBUSY; - oldmem_pfn_is_ram = fn; - return 0; + INIT_LIST_HEAD(&cb->next); + mutex_lock(&vmcore_mutex); + list_add_tail(&cb->next, &vmcore_cb_list); + /* + * Registering a vmcore callback after the vmcore was opened is + * very unusual (e.g., manual driver loading). + */ + if (vmcore_opened) + pr_warn_once("Unexpected vmcore callback registration\n"); + if (!vmcore_open && cb->get_device_ram) + vmcore_process_device_ram(cb); + mutex_unlock(&vmcore_mutex); } -EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram); +EXPORT_SYMBOL_GPL(register_vmcore_cb); -void unregister_oldmem_pfn_is_ram(void) +void unregister_vmcore_cb(struct vmcore_cb *cb) { - oldmem_pfn_is_ram = NULL; - wmb(); + mutex_lock(&vmcore_mutex); + list_del_rcu(&cb->next); + /* + * Unregistering a vmcore callback after the vmcore was opened is + * very unusual (e.g., forced driver removal), but we cannot stop + * unregistering. + */ + if (vmcore_opened) + pr_warn_once("Unexpected vmcore callback unregistration\n"); + mutex_unlock(&vmcore_mutex); + + synchronize_srcu(&vmcore_cb_srcu); } -EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram); +EXPORT_SYMBOL_GPL(unregister_vmcore_cb); -static int pfn_is_ram(unsigned long pfn) +static bool pfn_is_ram(unsigned long pfn) { - int (*fn)(unsigned long pfn); - /* pfn is ram unless fn() checks pagetype */ - int ret = 1; + struct vmcore_cb *cb; + bool ret = true; - /* - * Ask hypervisor if the pfn is really ram. - * A ballooned page contains no data and reading from such a page - * will cause high load in the hypervisor. - */ - fn = oldmem_pfn_is_ram; - if (fn) - ret = fn(pfn); + list_for_each_entry_srcu(cb, &vmcore_cb_list, next, + srcu_read_lock_held(&vmcore_cb_srcu)) { + if (unlikely(!cb->pfn_is_ram)) + continue; + ret = cb->pfn_is_ram(cb, pfn); + if (!ret) + break; + } return ret; } +static int open_vmcore(struct inode *inode, struct file *file) +{ + mutex_lock(&vmcore_mutex); + vmcore_opened = true; + if (vmcore_open + 1 == 0) { + mutex_unlock(&vmcore_mutex); + return -EBUSY; + } + vmcore_open++; + mutex_unlock(&vmcore_mutex); + + return 0; +} + +static int release_vmcore(struct inode *inode, struct file *file) +{ + mutex_lock(&vmcore_mutex); + vmcore_open--; + mutex_unlock(&vmcore_mutex); + + return 0; +} + /* Reads a page from the oldmem device from given offset. */ -static ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted) +ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, + u64 *ppos, bool encrypted) { unsigned long pfn, offset; - size_t nr_bytes; + ssize_t nr_bytes; ssize_t read = 0, tmp; + int idx; if (!count) return 0; @@ -113,6 +170,7 @@ static ssize_t read_from_oldmem(char *buf, size_t count, offset = (unsigned long)(*ppos % PAGE_SIZE); pfn = (unsigned long)(*ppos / PAGE_SIZE); + idx = srcu_read_lock(&vmcore_cb_srcu); do { if (count > (PAGE_SIZE - offset)) nr_bytes = PAGE_SIZE - offset; @@ -120,28 +178,29 @@ static ssize_t read_from_oldmem(char *buf, size_t count, nr_bytes = count; /* If pfn is not ram, return zeros for sparse dump files */ - if (pfn_is_ram(pfn) == 0) - memset(buf, 0, nr_bytes); - else { + if (!pfn_is_ram(pfn)) { + tmp = iov_iter_zero(nr_bytes, iter); + } else { if (encrypted) - tmp = copy_oldmem_page_encrypted(pfn, buf, + tmp = copy_oldmem_page_encrypted(iter, pfn, nr_bytes, - offset, - userbuf); + offset); else - tmp = copy_oldmem_page(pfn, buf, nr_bytes, - offset, userbuf); - - if (tmp < 0) - return tmp; + tmp = copy_oldmem_page(iter, pfn, nr_bytes, + offset); + } + if (tmp < nr_bytes) { + srcu_read_unlock(&vmcore_cb_srcu, idx); + return -EFAULT; } + *ppos += nr_bytes; count -= nr_bytes; - buf += nr_bytes; read += nr_bytes; ++pfn; offset = 0; } while (count); + srcu_read_unlock(&vmcore_cb_srcu, idx); return read; } @@ -165,7 +224,12 @@ void __weak elfcorehdr_free(unsigned long long addr) */ ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, false); + struct kvec kvec = { .iov_base = buf, .iov_len = count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, false); } /* @@ -173,7 +237,13 @@ ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) */ ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, sme_active()); + struct kvec kvec = { .iov_base = buf, .iov_len = count }; + struct iov_iter iter; + + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + + return read_from_oldmem(&iter, count, ppos, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); } /* @@ -190,60 +260,38 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, /* * Architectures which support memory encryption override this. */ -ssize_t __weak -copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, - unsigned long offset, int userbuf) -{ - return copy_oldmem_page(pfn, buf, csize, offset, userbuf); -} - -/* - * Copy to either kernel or user space - */ -static int copy_to(void *target, void *src, size_t size, int userbuf) +ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, + unsigned long pfn, size_t csize, unsigned long offset) { - if (userbuf) { - if (copy_to_user((char __user *) target, src, size)) - return -EFAULT; - } else { - memcpy(target, src, size); - } - return 0; + return copy_oldmem_page(iter, pfn, csize, offset); } #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP -static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf) +static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size) { struct vmcoredd_node *dump; u64 offset = 0; - int ret = 0; size_t tsz; char *buf; - mutex_lock(&vmcoredd_mutex); list_for_each_entry(dump, &vmcoredd_list, list) { if (start < offset + dump->size) { tsz = min(offset + (u64)dump->size - start, (u64)size); buf = dump->buf + start - offset; - if (copy_to(dst, buf, tsz, userbuf)) { - ret = -EFAULT; - goto out_unlock; - } + if (copy_to_iter(buf, tsz, iter) < tsz) + return -EFAULT; size -= tsz; start += tsz; - dst += tsz; /* Leave now if buffer filled already */ if (!size) - goto out_unlock; + return 0; } offset += dump->size; } -out_unlock: - mutex_unlock(&vmcoredd_mutex); - return ret; + return 0; } #ifdef CONFIG_MMU @@ -252,19 +300,16 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, { struct vmcoredd_node *dump; u64 offset = 0; - int ret = 0; size_t tsz; char *buf; - mutex_lock(&vmcoredd_mutex); list_for_each_entry(dump, &vmcoredd_list, list) { if (start < offset + dump->size) { tsz = min(offset + (u64)dump->size - start, (u64)size); buf = dump->buf + start - offset; - if (remap_vmalloc_range_partial(vma, dst, buf, tsz)) { - ret = -EFAULT; - goto out_unlock; - } + if (remap_vmalloc_range_partial(vma, dst, buf, 0, + tsz)) + return -EFAULT; size -= tsz; start += tsz; @@ -272,14 +317,12 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, /* Leave now if buffer filled already */ if (!size) - goto out_unlock; + return 0; } offset += dump->size; } -out_unlock: - mutex_unlock(&vmcoredd_mutex); - return ret; + return 0; } #endif /* CONFIG_MMU */ #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ @@ -287,37 +330,32 @@ out_unlock: /* Read from the ELF header and then the crash dump. On error, negative value is * returned otherwise number of bytes read are returned. */ -static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos, - int userbuf) +static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos) { + struct vmcore_range *m = NULL; ssize_t acc = 0, tmp; size_t tsz; u64 start; - struct vmcore *m = NULL; - if (buflen == 0 || *fpos >= vmcore_size) + if (!iov_iter_count(iter) || *fpos >= vmcore_size) return 0; - /* trim buflen to not go beyond EOF */ - if (buflen > vmcore_size - *fpos) - buflen = vmcore_size - *fpos; + iov_iter_truncate(iter, vmcore_size - *fpos); /* Read ELF core header */ if (*fpos < elfcorebuf_sz) { - tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen); - if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf)) + tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); + if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz) return -EFAULT; - buflen -= tsz; *fpos += tsz; - buffer += tsz; acc += tsz; /* leave now if filled buffer already */ - if (buflen == 0) + if (!iov_iter_count(iter)) return acc; } - /* Read Elf note segment */ + /* Read ELF note segment */ if (*fpos < elfcorebuf_sz + elfnotes_sz) { void *kaddr; @@ -334,71 +372,97 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos, /* Read device dumps */ if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - - (size_t)*fpos, buflen); + (size_t)*fpos, iov_iter_count(iter)); start = *fpos - elfcorebuf_sz; - if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf)) + if (vmcoredd_copy_dumps(iter, start, tsz)) return -EFAULT; - buflen -= tsz; *fpos += tsz; - buffer += tsz; acc += tsz; /* leave now if filled buffer already */ - if (!buflen) + if (!iov_iter_count(iter)) return acc; } #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ /* Read remaining elf notes */ - tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen); + tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, + iov_iter_count(iter)); kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; - if (copy_to(buffer, kaddr, tsz, userbuf)) + if (copy_to_iter(kaddr, tsz, iter) < tsz) return -EFAULT; - buflen -= tsz; *fpos += tsz; - buffer += tsz; acc += tsz; /* leave now if filled buffer already */ - if (buflen == 0) + if (!iov_iter_count(iter)) return acc; + + cond_resched(); } list_for_each_entry(m, &vmcore_list, list) { if (*fpos < m->offset + m->size) { tsz = (size_t)min_t(unsigned long long, m->offset + m->size - *fpos, - buflen); + iov_iter_count(iter)); start = m->paddr + *fpos - m->offset; - tmp = read_from_oldmem(buffer, tsz, &start, - userbuf, sme_active()); + tmp = read_from_oldmem(iter, tsz, &start, + cc_platform_has(CC_ATTR_MEM_ENCRYPT)); if (tmp < 0) return tmp; - buflen -= tsz; *fpos += tsz; - buffer += tsz; acc += tsz; /* leave now if filled buffer already */ - if (buflen == 0) + if (!iov_iter_count(iter)) return acc; } + + cond_resched(); } return acc; } -static ssize_t read_vmcore(struct file *file, char __user *buffer, - size_t buflen, loff_t *fpos) +static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) { - return __read_vmcore((__force char *) buffer, buflen, fpos, 1); + return __read_vmcore(iter, &iocb->ki_pos); } +/** + * vmcore_alloc_buf - allocate buffer in vmalloc memory + * @size: 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(). + * + * 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 *vmcore_alloc_buf(size_t size) +{ +#ifdef CONFIG_MMU + return vmalloc_user(size); +#else + return vzalloc(size); +#endif +} + +/* + * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is + * essential for mmap_vmcore() in order to map physically + * non-contiguous objects (ELF header, ELF note segment and memory + * regions in the 1st kernel pointed to by PT_LOAD entries) into + * virtually contiguous user-space in ELF layout. + */ +#ifdef CONFIG_MMU + /* * The vmcore fault handler uses the page cache and fills data using the - * standard __vmcore_read() function. + * standard __read_vmcore() function. * * On s390 the fault handler is used for memory regions that can't be mapped * directly with remap_pfn_range(). @@ -408,9 +472,10 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf) #ifdef CONFIG_S390 struct address_space *mapping = vmf->vma->vm_file->f_mapping; pgoff_t index = vmf->pgoff; + struct iov_iter iter; + struct kvec kvec; struct page *page; loff_t offset; - char *buf; int rc; page = find_or_create_page(mapping, index, GFP_KERNEL); @@ -418,8 +483,11 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf) return VM_FAULT_OOM; if (!PageUptodate(page)) { offset = (loff_t) index << PAGE_SHIFT; - buf = __va((page_to_pfn(page) << PAGE_SHIFT)); - rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0); + kvec.iov_base = page_address(page); + kvec.iov_len = PAGE_SIZE; + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE); + + rc = __read_vmcore(&iter, &offset); if (rc < 0) { unlock_page(page); put_page(page); @@ -439,33 +507,6 @@ static const struct vm_operations_struct vmcore_mmap_ops = { .fault = mmap_vmcore_fault, }; -/** - * 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(). - * - * 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 *vmcore_alloc_buf(size_t size) -{ -#ifdef CONFIG_MMU - return vmalloc_user(size); -#else - return vzalloc(size); -#endif -} - -/* - * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is - * essential for mmap_vmcore() in order to map physically - * non-contiguous objects (ELF header, ELF note segment and memory - * regions in the 1st kernel pointed to by PT_LOAD entries) into - * virtually contiguous user-space in ELF layout. - */ -#ifdef CONFIG_MMU /* * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages * reported as not being ram with the zero page. @@ -532,21 +573,26 @@ static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot) { + int ret, idx; + /* - * Check if oldmem_pfn_is_ram was registered to avoid - * looping over all pages without a reason. + * Check if a callback was registered to avoid looping over all + * pages without a reason. */ - if (oldmem_pfn_is_ram) - return remap_oldmem_pfn_checked(vma, from, pfn, size, prot); + idx = srcu_read_lock(&vmcore_cb_srcu); + if (!list_empty(&vmcore_cb_list)) + ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); else - return remap_oldmem_pfn_range(vma, from, pfn, size, prot); + ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); + srcu_read_unlock(&vmcore_cb_srcu, idx); + return ret; } static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) { size_t size = vma->vm_end - vma->vm_start; u64 start, end, len, tsz; - struct vmcore *m; + struct vmcore_range *m; start = (u64)vma->vm_pgoff << PAGE_SHIFT; end = start + size; @@ -557,8 +603,7 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) if (vma->vm_flags & (VM_WRITE | VM_EXEC)) return -EPERM; - vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC); - vma->vm_flags |= VM_MIXEDMAP; + vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC); vma->vm_ops = &vmcore_mmap_ops; len = 0; @@ -619,7 +664,7 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size); kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz; if (remap_vmalloc_range_partial(vma, vma->vm_start + len, - kaddr, tsz)) + kaddr, 0, tsz)) goto fail; size -= tsz; @@ -662,22 +707,19 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) } #endif -static const struct file_operations proc_vmcore_operations = { - .read = read_vmcore, - .llseek = default_llseek, - .mmap = mmap_vmcore, +static const struct proc_ops vmcore_proc_ops = { + .proc_open = open_vmcore, + .proc_release = release_vmcore, + .proc_read_iter = read_vmcore, + .proc_lseek = default_llseek, + .proc_mmap = mmap_vmcore, }; -static struct vmcore* __init get_new_element(void) -{ - return kzalloc(sizeof(struct vmcore), GFP_KERNEL); -} - static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz, struct list_head *vc_list) { + struct vmcore_range *m; u64 size; - struct vmcore *m; size = elfsz + elfnotesegsz; list_for_each_entry(m, vc_list, list) { @@ -852,7 +894,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; - phdr.p_align = 0; + phdr.p_align = 4; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf64_Ehdr); @@ -1043,7 +1085,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; - phdr.p_align = 0; + phdr.p_align = 4; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf32_Ehdr); @@ -1079,12 +1121,11 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ - /* Skip Elf header, program headers and Elf note segment. */ + /* Skip ELF header, program headers and ELF note segment. */ vmcore_off = elfsz + elfnotes_sz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { @@ -1098,13 +1139,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); size = end - start; - /* Add this contiguous chunk of memory to vmcore list.*/ - new = get_new_element(); - if (!new) + if (vmcore_alloc_add_range(vc_list, start, size)) return -ENOMEM; - new->paddr = start; - new->size = size; - list_add_tail(&new->list, vc_list); /* Update the program header offset. */ phdr_ptr->p_offset = vmcore_off + (paddr - start); @@ -1122,12 +1158,11 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, Elf32_Ehdr *ehdr_ptr; Elf32_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf32_Ehdr *)elfptr; phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ - /* Skip Elf header, program headers and Elf note segment. */ + /* Skip ELF header, program headers and ELF note segment. */ vmcore_off = elfsz + elfnotes_sz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { @@ -1141,13 +1176,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); size = end - start; - /* Add this contiguous chunk of memory to vmcore list.*/ - new = get_new_element(); - if (!new) + if (vmcore_alloc_add_range(vc_list, start, size)) return -ENOMEM; - new->paddr = start; - new->size = size; - list_add_tail(&new->list, vc_list); /* Update the program header offset */ phdr_ptr->p_offset = vmcore_off + (paddr - start); @@ -1160,10 +1190,10 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, struct list_head *vc_list) { + struct vmcore_range *m; loff_t vmcore_off; - struct vmcore *m; - /* Skip Elf header, program headers and Elf note segment. */ + /* Skip ELF header, program headers and ELF note segment. */ vmcore_off = elfsz + elfnotes_sz; list_for_each_entry(m, vc_list, list) { @@ -1188,7 +1218,7 @@ static int __init parse_crash_elf64_headers(void) addr = elfcorehdr_addr; - /* Read Elf header */ + /* Read ELF header */ rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr); if (rc < 0) return rc; @@ -1244,7 +1274,7 @@ static int __init parse_crash_elf32_headers(void) addr = elfcorehdr_addr; - /* Read Elf header */ + /* Read ELF header */ rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr); if (rc < 0) return rc; @@ -1345,18 +1375,17 @@ static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, 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)); + strscpy_pad(vdd_hdr->name, VMCOREDD_NOTE_NAME); + strscpy_pad(vdd_hdr->dump_name, data->dump_name); } /** - * vmcoredd_update_program_headers - Update all Elf program headers + * vmcoredd_update_program_headers - Update all ELF program headers * @elfptr: Pointer to elf header * @elfnotesz: Size of elf notes aligned to page size * @vmcoreddsz: Size of device dumps to be added to elf note header * - * Determine type of Elf header (Elf64 or Elf32) and update the elf note size. + * Determine type of ELF header (Elf64 or Elf32) and update the elf note size. * Also update the offsets of all the program headers after the elf note header. */ static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz, @@ -1414,10 +1443,10 @@ static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz, /** * vmcoredd_update_size - Update the total size of the device dumps and update - * Elf header + * ELF header * @dump_size: Size of the current device dump to be added to total size * - * Update the total size of all the device dumps and update the Elf program + * Update the total size of all the device dumps and update the ELF program * headers. Calculate the new offsets for the vmcore list and update the * total vmcore size. */ @@ -1441,7 +1470,7 @@ static void vmcoredd_update_size(size_t dump_size) * @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 + * 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) @@ -1451,15 +1480,18 @@ int vmcore_add_device_dump(struct vmcoredd_data *data) size_t data_size; int ret; + if (vmcoredd_disabled) { + pr_err_once("Device dump is disabled\n"); + return -EINVAL; + } + if (!data || !strlen(data->dump_name) || !data->vmcoredd_callback || !data->size) return -EINVAL; dump = vzalloc(sizeof(*dump)); - if (!dump) { - ret = -ENOMEM; - goto out_err; - } + if (!dump) + return -ENOMEM; /* Keep size of the buffer page aligned so that it can be mmaped */ data_size = roundup(sizeof(struct vmcoredd_header) + data->size, @@ -1484,31 +1516,186 @@ int vmcore_add_device_dump(struct vmcoredd_data *data) 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); + /* Add the dump to driver sysfs list and update the elfcore hdr */ + scoped_guard(mutex, &vmcore_mutex) { + if (vmcore_opened) + pr_warn_once("Unexpected adding of device dump\n"); + if (vmcore_open) { + ret = -EBUSY; + goto out_err; + } - vmcoredd_update_size(data_size); + list_add_tail(&dump->list, &vmcoredd_list); + vmcoredd_update_size(data_size); + } return 0; out_err: - if (buf) - vfree(buf); - - if (dump) - vfree(dump); + vfree(buf); + vfree(dump); return ret; } EXPORT_SYMBOL(vmcore_add_device_dump); #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ +#ifdef CONFIG_PROC_VMCORE_DEVICE_RAM +static int vmcore_realloc_elfcore_buffer_elf64(size_t new_size) +{ + char *elfcorebuf_new; + + if (WARN_ON_ONCE(new_size < elfcorebuf_sz)) + return -EINVAL; + if (get_order(elfcorebuf_sz_orig) == get_order(new_size)) { + elfcorebuf_sz_orig = new_size; + return 0; + } + + elfcorebuf_new = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + get_order(new_size)); + if (!elfcorebuf_new) + return -ENOMEM; + memcpy(elfcorebuf_new, elfcorebuf, elfcorebuf_sz); + free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig)); + elfcorebuf = elfcorebuf_new; + elfcorebuf_sz_orig = new_size; + return 0; +} + +static void vmcore_reset_offsets_elf64(void) +{ + Elf64_Phdr *phdr_start = (Elf64_Phdr *)(elfcorebuf + sizeof(Elf64_Ehdr)); + loff_t vmcore_off = elfcorebuf_sz + elfnotes_sz; + Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfcorebuf; + Elf64_Phdr *phdr; + int i; + + for (i = 0, phdr = phdr_start; i < ehdr->e_phnum; i++, phdr++) { + u64 start, end; + + /* + * After merge_note_headers_elf64() we should only have a single + * PT_NOTE entry that starts immediately after elfcorebuf_sz. + */ + if (phdr->p_type == PT_NOTE) { + phdr->p_offset = elfcorebuf_sz; + continue; + } + + start = rounddown(phdr->p_offset, PAGE_SIZE); + end = roundup(phdr->p_offset + phdr->p_memsz, PAGE_SIZE); + phdr->p_offset = vmcore_off + (phdr->p_offset - start); + vmcore_off = vmcore_off + end - start; + } + set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); +} + +static int vmcore_add_device_ram_elf64(struct list_head *list, size_t count) +{ + Elf64_Phdr *phdr_start = (Elf64_Phdr *)(elfcorebuf + sizeof(Elf64_Ehdr)); + Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfcorebuf; + struct vmcore_range *cur; + Elf64_Phdr *phdr; + size_t new_size; + int rc; + + if ((Elf32_Half)(ehdr->e_phnum + count) != ehdr->e_phnum + count) { + pr_err("too many device ram ranges\n"); + return -ENOSPC; + } + + /* elfcorebuf_sz must always cover full pages. */ + new_size = sizeof(Elf64_Ehdr) + + (ehdr->e_phnum + count) * sizeof(Elf64_Phdr); + new_size = roundup(new_size, PAGE_SIZE); + + /* + * Make sure we have sufficient space to include the new PT_LOAD + * entries. + */ + rc = vmcore_realloc_elfcore_buffer_elf64(new_size); + if (rc) { + pr_err("resizing elfcore failed\n"); + return rc; + } + + /* Modify our used elfcore buffer size to cover the new entries. */ + elfcorebuf_sz = new_size; + + /* Fill the added PT_LOAD entries. */ + phdr = phdr_start + ehdr->e_phnum; + list_for_each_entry(cur, list, list) { + WARN_ON_ONCE(!IS_ALIGNED(cur->paddr | cur->size, PAGE_SIZE)); + elfcorehdr_fill_device_ram_ptload_elf64(phdr, cur->paddr, cur->size); + + /* p_offset will be adjusted later. */ + phdr++; + ehdr->e_phnum++; + } + list_splice_tail(list, &vmcore_list); + + /* We changed elfcorebuf_sz and added new entries; reset all offsets. */ + vmcore_reset_offsets_elf64(); + + /* Finally, recalculate the total vmcore size. */ + vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz, + &vmcore_list); + proc_vmcore->size = vmcore_size; + return 0; +} + +static void vmcore_process_device_ram(struct vmcore_cb *cb) +{ + unsigned char *e_ident = (unsigned char *)elfcorebuf; + struct vmcore_range *first, *m; + LIST_HEAD(list); + int count; + + /* We only support Elf64 dumps for now. */ + if (WARN_ON_ONCE(e_ident[EI_CLASS] != ELFCLASS64)) { + pr_err("device ram ranges only support Elf64\n"); + return; + } + + if (cb->get_device_ram(cb, &list)) { + pr_err("obtaining device ram ranges failed\n"); + return; + } + count = list_count_nodes(&list); + if (!count) + return; + + /* + * For some reason these ranges are already know? Might happen + * with unusual register->unregister->register sequences; we'll simply + * sanity check using the first range. + */ + first = list_first_entry(&list, struct vmcore_range, list); + list_for_each_entry(m, &vmcore_list, list) { + unsigned long long m_end = m->paddr + m->size; + unsigned long long first_end = first->paddr + first->size; + + if (first->paddr < m_end && m->paddr < first_end) + goto out_free; + } + + /* If adding the mem nodes succeeds, they must not be freed. */ + if (!vmcore_add_device_ram_elf64(&list, count)) + return; +out_free: + vmcore_free_ranges(&list); +} +#else /* !CONFIG_PROC_VMCORE_DEVICE_RAM */ +static void vmcore_process_device_ram(struct vmcore_cb *cb) +{ +} +#endif /* CONFIG_PROC_VMCORE_DEVICE_RAM */ + /* 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); + mutex_lock(&vmcore_mutex); while (!list_empty(&vmcoredd_list)) { struct vmcoredd_node *dump; @@ -1518,7 +1705,7 @@ static void vmcore_free_device_dumps(void) vfree(dump->buf); vfree(dump); } - mutex_unlock(&vmcoredd_mutex); + mutex_unlock(&vmcore_mutex); #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ } @@ -1539,13 +1726,14 @@ static int __init vmcore_init(void) return rc; rc = parse_crash_elf_headers(); if (rc) { - pr_warn("Kdump: vmcore not initialized\n"); + elfcorehdr_free(elfcorehdr_addr); + pr_warn("not initialized\n"); return rc; } elfcorehdr_free(elfcorehdr_addr); elfcorehdr_addr = ELFCORE_ADDR_ERR; - proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations); + proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops); if (proc_vmcore) proc_vmcore->size = vmcore_size; return 0; @@ -1560,14 +1748,7 @@ void vmcore_cleanup(void) proc_vmcore = NULL; } - /* clear the vmcore list. */ - while (!list_empty(&vmcore_list)) { - struct vmcore *m; - - m = list_first_entry(&vmcore_list, struct vmcore, list); - list_del(&m->list); - kfree(m); - } + vmcore_free_ranges(&vmcore_list); free_elfcorebuf(); /* clear vmcore device dump list */ |