OpenCloudOS-Kernel/drivers/remoteproc/remoteproc_coredump.c

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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);
}
}
/**
* 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, (void const __iomem *)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);
}
/**
* 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);