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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Coredump functionality for Remoteproc framework.
- *
- * Copyright (c) 2020, The Linux Foundation. All rights reserved.
- */
- #include <linux/completion.h>
- #include <linux/devcoredump.h>
- #include <linux/device.h>
- #include <linux/kernel.h>
- #include <linux/remoteproc.h>
- #include "remoteproc_internal.h"
- #include "remoteproc_elf_helpers.h"
- struct rproc_coredump_state {
- struct rproc *rproc;
- void *header;
- struct completion dump_done;
- };
- /**
- * rproc_coredump_cleanup() - clean up dump_segments list
- * @rproc: the remote processor handle
- */
- void rproc_coredump_cleanup(struct rproc *rproc)
- {
- struct rproc_dump_segment *entry, *tmp;
- list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
- list_del(&entry->node);
- kfree(entry);
- }
- }
- EXPORT_SYMBOL(rproc_coredump_cleanup);
- /**
- * rproc_coredump_add_segment() - add segment of device memory to coredump
- * @rproc: handle of a remote processor
- * @da: device address
- * @size: size of segment
- *
- * Add device memory to the list of segments to be included in a coredump for
- * the remoteproc.
- *
- * Return: 0 on success, negative errno on error.
- */
- int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
- {
- struct rproc_dump_segment *segment;
- segment = kzalloc(sizeof(*segment), GFP_KERNEL);
- if (!segment)
- return -ENOMEM;
- segment->da = da;
- segment->size = size;
- list_add_tail(&segment->node, &rproc->dump_segments);
- return 0;
- }
- EXPORT_SYMBOL(rproc_coredump_add_segment);
- /**
- * rproc_coredump_add_custom_segment() - add custom coredump segment
- * @rproc: handle of a remote processor
- * @da: device address
- * @size: size of segment
- * @dumpfn: custom dump function called for each segment during coredump
- * @priv: private data
- *
- * Add device memory to the list of segments to be included in the coredump
- * and associate the segment with the given custom dump function and private
- * data.
- *
- * Return: 0 on success, negative errno on error.
- */
- int rproc_coredump_add_custom_segment(struct rproc *rproc,
- dma_addr_t da, size_t size,
- void (*dumpfn)(struct rproc *rproc,
- struct rproc_dump_segment *segment,
- void *dest, size_t offset,
- size_t size),
- void *priv)
- {
- struct rproc_dump_segment *segment;
- segment = kzalloc(sizeof(*segment), GFP_KERNEL);
- if (!segment)
- return -ENOMEM;
- segment->da = da;
- segment->size = size;
- segment->priv = priv;
- segment->dump = dumpfn;
- list_add_tail(&segment->node, &rproc->dump_segments);
- return 0;
- }
- EXPORT_SYMBOL(rproc_coredump_add_custom_segment);
- /**
- * rproc_coredump_set_elf_info() - set coredump elf information
- * @rproc: handle of a remote processor
- * @class: elf class for coredump elf file
- * @machine: elf machine for coredump elf file
- *
- * Set elf information which will be used for coredump elf file.
- *
- * Return: 0 on success, negative errno on error.
- */
- int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
- {
- if (class != ELFCLASS64 && class != ELFCLASS32)
- return -EINVAL;
- rproc->elf_class = class;
- rproc->elf_machine = machine;
- return 0;
- }
- EXPORT_SYMBOL(rproc_coredump_set_elf_info);
- static void rproc_coredump_free(void *data)
- {
- struct rproc_coredump_state *dump_state = data;
- vfree(dump_state->header);
- complete(&dump_state->dump_done);
- }
- static void *rproc_coredump_find_segment(loff_t user_offset,
- struct list_head *segments,
- size_t *data_left)
- {
- struct rproc_dump_segment *segment;
- list_for_each_entry(segment, segments, node) {
- if (user_offset < segment->size) {
- *data_left = segment->size - user_offset;
- return segment;
- }
- user_offset -= segment->size;
- }
- *data_left = 0;
- return NULL;
- }
- static void rproc_copy_segment(struct rproc *rproc, void *dest,
- struct rproc_dump_segment *segment,
- size_t offset, size_t size)
- {
- bool is_iomem = false;
- void *ptr;
- if (segment->dump) {
- segment->dump(rproc, segment, dest, offset, size);
- } else {
- ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
- if (!ptr) {
- dev_err(&rproc->dev,
- "invalid copy request for segment %pad with offset %zu and size %zu)\n",
- &segment->da, offset, size);
- memset(dest, 0xff, size);
- } else {
- if (is_iomem)
- memcpy_fromio(dest, ptr, size);
- else
- memcpy(dest, ptr, size);
- }
- }
- }
- static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
- void *data, size_t header_sz)
- {
- size_t seg_data, bytes_left = count;
- ssize_t copy_sz;
- struct rproc_dump_segment *seg;
- struct rproc_coredump_state *dump_state = data;
- struct rproc *rproc = dump_state->rproc;
- void *elfcore = dump_state->header;
- /* Copy the vmalloc'ed header first. */
- if (offset < header_sz) {
- copy_sz = memory_read_from_buffer(buffer, count, &offset,
- elfcore, header_sz);
- return copy_sz;
- }
- /*
- * Find out the segment memory chunk to be copied based on offset.
- * Keep copying data until count bytes are read.
- */
- while (bytes_left) {
- seg = rproc_coredump_find_segment(offset - header_sz,
- &rproc->dump_segments,
- &seg_data);
- /* EOF check */
- if (!seg) {
- dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
- offset);
- break;
- }
- copy_sz = min_t(size_t, bytes_left, seg_data);
- rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
- copy_sz);
- offset += copy_sz;
- buffer += copy_sz;
- bytes_left -= copy_sz;
- }
- return count - bytes_left;
- }
- /**
- * rproc_coredump() - perform coredump
- * @rproc: rproc handle
- *
- * This function will generate an ELF header for the registered segments
- * and create a devcoredump device associated with rproc. Based on the
- * coredump configuration this function will directly copy the segments
- * from device memory to userspace or copy segments from device memory to
- * a separate buffer, which can then be read by userspace.
- * The first approach avoids using extra vmalloc memory. But it will stall
- * recovery flow until dump is read by userspace.
- */
- void rproc_coredump(struct rproc *rproc)
- {
- struct rproc_dump_segment *segment;
- void *phdr;
- void *ehdr;
- size_t data_size;
- size_t offset;
- void *data;
- u8 class = rproc->elf_class;
- int phnum = 0;
- struct rproc_coredump_state dump_state;
- enum rproc_dump_mechanism dump_conf = rproc->dump_conf;
- if (list_empty(&rproc->dump_segments) ||
- dump_conf == RPROC_COREDUMP_DISABLED)
- return;
- if (class == ELFCLASSNONE) {
- dev_err(&rproc->dev, "Elf class is not set\n");
- return;
- }
- data_size = elf_size_of_hdr(class);
- list_for_each_entry(segment, &rproc->dump_segments, node) {
- /*
- * For default configuration buffer includes headers & segments.
- * For inline dump buffer just includes headers as segments are
- * directly read from device memory.
- */
- data_size += elf_size_of_phdr(class);
- if (dump_conf == RPROC_COREDUMP_ENABLED)
- data_size += segment->size;
- phnum++;
- }
- data = vmalloc(data_size);
- if (!data)
- return;
- ehdr = data;
- memset(ehdr, 0, elf_size_of_hdr(class));
- /* e_ident field is common for both elf32 and elf64 */
- elf_hdr_init_ident(ehdr, class);
- elf_hdr_set_e_type(class, ehdr, ET_CORE);
- elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
- elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
- elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
- elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
- elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
- elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
- elf_hdr_set_e_phnum(class, ehdr, phnum);
- phdr = data + elf_hdr_get_e_phoff(class, ehdr);
- offset = elf_hdr_get_e_phoff(class, ehdr);
- offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);
- list_for_each_entry(segment, &rproc->dump_segments, node) {
- memset(phdr, 0, elf_size_of_phdr(class));
- elf_phdr_set_p_type(class, phdr, PT_LOAD);
- elf_phdr_set_p_offset(class, phdr, offset);
- elf_phdr_set_p_vaddr(class, phdr, segment->da);
- elf_phdr_set_p_paddr(class, phdr, segment->da);
- elf_phdr_set_p_filesz(class, phdr, segment->size);
- elf_phdr_set_p_memsz(class, phdr, segment->size);
- elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
- elf_phdr_set_p_align(class, phdr, 0);
- if (dump_conf == RPROC_COREDUMP_ENABLED)
- rproc_copy_segment(rproc, data + offset, segment, 0,
- segment->size);
- offset += elf_phdr_get_p_filesz(class, phdr);
- phdr += elf_size_of_phdr(class);
- }
- if (dump_conf == RPROC_COREDUMP_ENABLED) {
- dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
- return;
- }
- /* Initialize the dump state struct to be used by rproc_coredump_read */
- dump_state.rproc = rproc;
- dump_state.header = data;
- init_completion(&dump_state.dump_done);
- dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
- rproc_coredump_read, rproc_coredump_free);
- /*
- * Wait until the dump is read and free is called. Data is freed
- * by devcoredump framework automatically after 5 minutes.
- */
- wait_for_completion(&dump_state.dump_done);
- }
- EXPORT_SYMBOL(rproc_coredump);
- /**
- * rproc_coredump_using_sections() - perform coredump using section headers
- * @rproc: rproc handle
- *
- * This function will generate an ELF header for the registered sections of
- * segments and create a devcoredump device associated with rproc. Based on
- * the coredump configuration this function will directly copy the segments
- * from device memory to userspace or copy segments from device memory to
- * a separate buffer, which can then be read by userspace.
- * The first approach avoids using extra vmalloc memory. But it will stall
- * recovery flow until dump is read by userspace.
- */
- void rproc_coredump_using_sections(struct rproc *rproc)
- {
- struct rproc_dump_segment *segment;
- void *shdr;
- void *ehdr;
- size_t data_size;
- size_t strtbl_size = 0;
- size_t strtbl_index = 1;
- size_t offset;
- void *data;
- u8 class = rproc->elf_class;
- int shnum;
- struct rproc_coredump_state dump_state;
- unsigned int dump_conf = rproc->dump_conf;
- char *str_tbl = "STR_TBL";
- if (list_empty(&rproc->dump_segments) ||
- dump_conf == RPROC_COREDUMP_DISABLED)
- return;
- if (class == ELFCLASSNONE) {
- dev_err(&rproc->dev, "Elf class is not set\n");
- return;
- }
- /*
- * We allocate two extra section headers. The first one is null.
- * Second section header is for the string table. Also space is
- * allocated for string table.
- */
- data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
- shnum = 2;
- /* the extra byte is for the null character at index 0 */
- strtbl_size += strlen(str_tbl) + 2;
- list_for_each_entry(segment, &rproc->dump_segments, node) {
- data_size += elf_size_of_shdr(class);
- strtbl_size += strlen(segment->priv) + 1;
- if (dump_conf == RPROC_COREDUMP_ENABLED)
- data_size += segment->size;
- shnum++;
- }
- data_size += strtbl_size;
- data = vmalloc(data_size);
- if (!data)
- return;
- ehdr = data;
- memset(ehdr, 0, elf_size_of_hdr(class));
- /* e_ident field is common for both elf32 and elf64 */
- elf_hdr_init_ident(ehdr, class);
- elf_hdr_set_e_type(class, ehdr, ET_CORE);
- elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
- elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
- elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
- elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
- elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
- elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
- elf_hdr_set_e_shnum(class, ehdr, shnum);
- elf_hdr_set_e_shstrndx(class, ehdr, 1);
- /*
- * The zeroth index of the section header is reserved and is rarely used.
- * Set the section header as null (SHN_UNDEF) and move to the next one.
- */
- shdr = data + elf_hdr_get_e_shoff(class, ehdr);
- memset(shdr, 0, elf_size_of_shdr(class));
- shdr += elf_size_of_shdr(class);
- /* Initialize the string table. */
- offset = elf_hdr_get_e_shoff(class, ehdr) +
- elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
- memset(data + offset, 0, strtbl_size);
- /* Fill in the string table section header. */
- memset(shdr, 0, elf_size_of_shdr(class));
- elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
- elf_shdr_set_sh_offset(class, shdr, offset);
- elf_shdr_set_sh_size(class, shdr, strtbl_size);
- elf_shdr_set_sh_entsize(class, shdr, 0);
- elf_shdr_set_sh_flags(class, shdr, 0);
- elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
- offset += elf_shdr_get_sh_size(class, shdr);
- shdr += elf_size_of_shdr(class);
- list_for_each_entry(segment, &rproc->dump_segments, node) {
- memset(shdr, 0, elf_size_of_shdr(class));
- elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
- elf_shdr_set_sh_offset(class, shdr, offset);
- elf_shdr_set_sh_addr(class, shdr, segment->da);
- elf_shdr_set_sh_size(class, shdr, segment->size);
- elf_shdr_set_sh_entsize(class, shdr, 0);
- elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
- elf_shdr_set_sh_name(class, shdr,
- elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));
- /* No need to copy segments for inline dumps */
- if (dump_conf == RPROC_COREDUMP_ENABLED)
- rproc_copy_segment(rproc, data + offset, segment, 0,
- segment->size);
- offset += elf_shdr_get_sh_size(class, shdr);
- shdr += elf_size_of_shdr(class);
- }
- if (dump_conf == RPROC_COREDUMP_ENABLED) {
- dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
- return;
- }
- /* Initialize the dump state struct to be used by rproc_coredump_read */
- dump_state.rproc = rproc;
- dump_state.header = data;
- init_completion(&dump_state.dump_done);
- dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
- rproc_coredump_read, rproc_coredump_free);
- /* Wait until the dump is read and free is called. Data is freed
- * by devcoredump framework automatically after 5 minutes.
- */
- wait_for_completion(&dump_state.dump_done);
- }
- EXPORT_SYMBOL(rproc_coredump_using_sections);
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