linux/fs/pstore/ram.c
Nícolas F. R. A. Prado 12dc54f568 pstore/ram: Register to module device table
Register the compatible for this module on the module device table so
it can be automatically loaded when a matching DT node is present,
allowing logging of panics and oopses without any intervention.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240110210600.787703-2-nfraprado@collabora.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-22 10:37:21 -08:00

985 lines
26 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* RAM Oops/Panic logger
*
* Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
* Copyright (C) 2011 Kees Cook <keescook@chromium.org>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/pstore.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/compiler.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/mm.h>
#include "internal.h"
#include "ram_internal.h"
#define RAMOOPS_KERNMSG_HDR "===="
#define MIN_MEM_SIZE 4096UL
static ulong record_size = MIN_MEM_SIZE;
module_param(record_size, ulong, 0400);
MODULE_PARM_DESC(record_size,
"size of each dump done on oops/panic");
static ulong ramoops_console_size = MIN_MEM_SIZE;
module_param_named(console_size, ramoops_console_size, ulong, 0400);
MODULE_PARM_DESC(console_size, "size of kernel console log");
static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
MODULE_PARM_DESC(pmsg_size, "size of user space message log");
static unsigned long long mem_address;
module_param_hw(mem_address, ullong, other, 0400);
MODULE_PARM_DESC(mem_address,
"start of reserved RAM used to store oops/panic logs");
static ulong mem_size;
module_param(mem_size, ulong, 0400);
MODULE_PARM_DESC(mem_size,
"size of reserved RAM used to store oops/panic logs");
static unsigned int mem_type;
module_param(mem_type, uint, 0400);
MODULE_PARM_DESC(mem_type,
"memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
static int ramoops_max_reason = -1;
module_param_named(max_reason, ramoops_max_reason, int, 0400);
MODULE_PARM_DESC(max_reason,
"maximum reason for kmsg dump (default 2: Oops and Panic) ");
static int ramoops_ecc;
module_param_named(ecc, ramoops_ecc, int, 0400);
MODULE_PARM_DESC(ramoops_ecc,
"if non-zero, the option enables ECC support and specifies "
"ECC buffer size in bytes (1 is a special value, means 16 "
"bytes ECC)");
static int ramoops_dump_oops = -1;
module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
MODULE_PARM_DESC(dump_oops,
"(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
struct ramoops_context {
struct persistent_ram_zone **dprzs; /* Oops dump zones */
struct persistent_ram_zone *cprz; /* Console zone */
struct persistent_ram_zone **fprzs; /* Ftrace zones */
struct persistent_ram_zone *mprz; /* PMSG zone */
phys_addr_t phys_addr;
unsigned long size;
unsigned int memtype;
size_t record_size;
size_t console_size;
size_t ftrace_size;
size_t pmsg_size;
u32 flags;
struct persistent_ram_ecc_info ecc_info;
unsigned int max_dump_cnt;
unsigned int dump_write_cnt;
/* _read_cnt need clear on ramoops_pstore_open */
unsigned int dump_read_cnt;
unsigned int console_read_cnt;
unsigned int max_ftrace_cnt;
unsigned int ftrace_read_cnt;
unsigned int pmsg_read_cnt;
struct pstore_info pstore;
};
static struct platform_device *dummy;
static int ramoops_pstore_open(struct pstore_info *psi)
{
struct ramoops_context *cxt = psi->data;
cxt->dump_read_cnt = 0;
cxt->console_read_cnt = 0;
cxt->ftrace_read_cnt = 0;
cxt->pmsg_read_cnt = 0;
return 0;
}
static struct persistent_ram_zone *
ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
struct pstore_record *record)
{
struct persistent_ram_zone *prz;
/* Give up if we never existed or have hit the end. */
if (!przs)
return NULL;
prz = przs[id];
if (!prz)
return NULL;
/* Update old/shadowed buffer. */
if (prz->type == PSTORE_TYPE_DMESG)
persistent_ram_save_old(prz);
if (!persistent_ram_old_size(prz))
return NULL;
record->type = prz->type;
record->id = id;
return prz;
}
static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
bool *compressed)
{
char data_type;
int header_length = 0;
if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
(time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
&header_length) == 3) {
time->tv_nsec *= 1000;
if (data_type == 'C')
*compressed = true;
else
*compressed = false;
} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
(time64_t *)&time->tv_sec, &time->tv_nsec,
&header_length) == 2) {
time->tv_nsec *= 1000;
*compressed = false;
} else {
time->tv_sec = 0;
time->tv_nsec = 0;
*compressed = false;
}
return header_length;
}
static bool prz_ok(struct persistent_ram_zone *prz)
{
return !!prz && !!(persistent_ram_old_size(prz) +
persistent_ram_ecc_string(prz, NULL, 0));
}
static ssize_t ramoops_pstore_read(struct pstore_record *record)
{
ssize_t size = 0;
struct ramoops_context *cxt = record->psi->data;
struct persistent_ram_zone *prz = NULL;
int header_length = 0;
bool free_prz = false;
/*
* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
* PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
* valid time stamps, so it is initialized to zero.
*/
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
record->compressed = false;
/* Find the next valid persistent_ram_zone for DMESG */
while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
record);
if (!prz_ok(prz))
continue;
header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
&record->time,
&record->compressed);
/* Clear and skip this DMESG record if it has no valid header */
if (!header_length) {
persistent_ram_free_old(prz);
persistent_ram_zap(prz);
prz = NULL;
}
}
if (!prz_ok(prz) && !cxt->console_read_cnt++)
prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
/* ftrace is last since it may want to dynamically allocate memory. */
if (!prz_ok(prz)) {
if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
!cxt->ftrace_read_cnt++) {
prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
record);
} else {
/*
* Build a new dummy record which combines all the
* per-cpu records including metadata and ecc info.
*/
struct persistent_ram_zone *tmp_prz, *prz_next;
tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
GFP_KERNEL);
if (!tmp_prz)
return -ENOMEM;
prz = tmp_prz;
free_prz = true;
while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
prz_next = ramoops_get_next_prz(cxt->fprzs,
cxt->ftrace_read_cnt++, record);
if (!prz_ok(prz_next))
continue;
tmp_prz->ecc_info = prz_next->ecc_info;
tmp_prz->corrected_bytes +=
prz_next->corrected_bytes;
tmp_prz->bad_blocks += prz_next->bad_blocks;
size = pstore_ftrace_combine_log(
&tmp_prz->old_log,
&tmp_prz->old_log_size,
prz_next->old_log,
prz_next->old_log_size);
if (size)
goto out;
}
record->id = 0;
}
}
if (!prz_ok(prz)) {
size = 0;
goto out;
}
size = persistent_ram_old_size(prz) - header_length;
/* ECC correction notice */
record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
record->buf = kvzalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
if (record->buf == NULL) {
size = -ENOMEM;
goto out;
}
memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
size);
persistent_ram_ecc_string(prz, record->buf + size,
record->ecc_notice_size + 1);
out:
if (free_prz) {
kvfree(prz->old_log);
kfree(prz);
}
return size;
}
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
struct pstore_record *record)
{
char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
size_t len;
len = scnprintf(hdr, sizeof(hdr),
RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
(time64_t)record->time.tv_sec,
record->time.tv_nsec / 1000,
record->compressed ? 'C' : 'D');
persistent_ram_write(prz, hdr, len);
return len;
}
static int notrace ramoops_pstore_write(struct pstore_record *record)
{
struct ramoops_context *cxt = record->psi->data;
struct persistent_ram_zone *prz;
size_t size, hlen;
if (record->type == PSTORE_TYPE_CONSOLE) {
if (!cxt->cprz)
return -ENOMEM;
persistent_ram_write(cxt->cprz, record->buf, record->size);
return 0;
} else if (record->type == PSTORE_TYPE_FTRACE) {
int zonenum;
if (!cxt->fprzs)
return -ENOMEM;
/*
* Choose zone by if we're using per-cpu buffers.
*/
if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
zonenum = smp_processor_id();
else
zonenum = 0;
persistent_ram_write(cxt->fprzs[zonenum], record->buf,
record->size);
return 0;
} else if (record->type == PSTORE_TYPE_PMSG) {
pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
return -EINVAL;
}
if (record->type != PSTORE_TYPE_DMESG)
return -EINVAL;
/*
* We could filter on record->reason here if we wanted to (which
* would duplicate what happened before the "max_reason" setting
* was added), but that would defeat the purpose of a system
* changing printk.always_kmsg_dump, so instead log everything that
* the kmsg dumper sends us, since it should be doing the filtering
* based on the combination of printk.always_kmsg_dump and our
* requested "max_reason".
*/
/*
* Explicitly only take the first part of any new crash.
* If our buffer is larger than kmsg_bytes, this can never happen,
* and if our buffer is smaller than kmsg_bytes, we don't want the
* report split across multiple records.
*/
if (record->part != 1)
return -ENOSPC;
if (!cxt->dprzs)
return -ENOSPC;
prz = cxt->dprzs[cxt->dump_write_cnt];
/*
* Since this is a new crash dump, we need to reset the buffer in
* case it still has an old dump present. Without this, the new dump
* will get appended, which would seriously confuse anything trying
* to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
* expects to find a dump header in the beginning of buffer data, so
* we must to reset the buffer values, in order to ensure that the
* header will be written to the beginning of the buffer.
*/
persistent_ram_zap(prz);
/* Build header and append record contents. */
hlen = ramoops_write_kmsg_hdr(prz, record);
if (!hlen)
return -ENOMEM;
size = record->size;
if (size + hlen > prz->buffer_size)
size = prz->buffer_size - hlen;
persistent_ram_write(prz, record->buf, size);
cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
return 0;
}
static int notrace ramoops_pstore_write_user(struct pstore_record *record,
const char __user *buf)
{
if (record->type == PSTORE_TYPE_PMSG) {
struct ramoops_context *cxt = record->psi->data;
if (!cxt->mprz)
return -ENOMEM;
return persistent_ram_write_user(cxt->mprz, buf, record->size);
}
return -EINVAL;
}
static int ramoops_pstore_erase(struct pstore_record *record)
{
struct ramoops_context *cxt = record->psi->data;
struct persistent_ram_zone *prz;
switch (record->type) {
case PSTORE_TYPE_DMESG:
if (record->id >= cxt->max_dump_cnt)
return -EINVAL;
prz = cxt->dprzs[record->id];
break;
case PSTORE_TYPE_CONSOLE:
prz = cxt->cprz;
break;
case PSTORE_TYPE_FTRACE:
if (record->id >= cxt->max_ftrace_cnt)
return -EINVAL;
prz = cxt->fprzs[record->id];
break;
case PSTORE_TYPE_PMSG:
prz = cxt->mprz;
break;
default:
return -EINVAL;
}
persistent_ram_free_old(prz);
persistent_ram_zap(prz);
return 0;
}
static struct ramoops_context oops_cxt = {
.pstore = {
.owner = THIS_MODULE,
.name = "ramoops",
.open = ramoops_pstore_open,
.read = ramoops_pstore_read,
.write = ramoops_pstore_write,
.write_user = ramoops_pstore_write_user,
.erase = ramoops_pstore_erase,
},
};
static void ramoops_free_przs(struct ramoops_context *cxt)
{
int i;
/* Free pmsg PRZ */
persistent_ram_free(&cxt->mprz);
/* Free console PRZ */
persistent_ram_free(&cxt->cprz);
/* Free dump PRZs */
if (cxt->dprzs) {
for (i = 0; i < cxt->max_dump_cnt; i++)
persistent_ram_free(&cxt->dprzs[i]);
kfree(cxt->dprzs);
cxt->dprzs = NULL;
cxt->max_dump_cnt = 0;
}
/* Free ftrace PRZs */
if (cxt->fprzs) {
for (i = 0; i < cxt->max_ftrace_cnt; i++)
persistent_ram_free(&cxt->fprzs[i]);
kfree(cxt->fprzs);
cxt->fprzs = NULL;
cxt->max_ftrace_cnt = 0;
}
}
static int ramoops_init_przs(const char *name,
struct device *dev, struct ramoops_context *cxt,
struct persistent_ram_zone ***przs,
phys_addr_t *paddr, size_t mem_sz,
ssize_t record_size,
unsigned int *cnt, u32 sig, u32 flags)
{
int err = -ENOMEM;
int i;
size_t zone_sz;
struct persistent_ram_zone **prz_ar;
/* Allocate nothing for 0 mem_sz or 0 record_size. */
if (mem_sz == 0 || record_size == 0) {
*cnt = 0;
return 0;
}
/*
* If we have a negative record size, calculate it based on
* mem_sz / *cnt. If we have a positive record size, calculate
* cnt from mem_sz / record_size.
*/
if (record_size < 0) {
if (*cnt == 0)
return 0;
record_size = mem_sz / *cnt;
if (record_size == 0) {
dev_err(dev, "%s record size == 0 (%zu / %u)\n",
name, mem_sz, *cnt);
goto fail;
}
} else {
*cnt = mem_sz / record_size;
if (*cnt == 0) {
dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
name, mem_sz, record_size);
goto fail;
}
}
if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
name,
mem_sz, (unsigned long long)*paddr,
cxt->size, (unsigned long long)cxt->phys_addr);
goto fail;
}
zone_sz = mem_sz / *cnt;
zone_sz = ALIGN_DOWN(zone_sz, 2);
if (!zone_sz) {
dev_err(dev, "%s zone size == 0\n", name);
goto fail;
}
prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
if (!prz_ar)
goto fail;
for (i = 0; i < *cnt; i++) {
char *label;
if (*cnt == 1)
label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
else
label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
name, i, *cnt - 1);
prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
&cxt->ecc_info,
cxt->memtype, flags, label);
kfree(label);
if (IS_ERR(prz_ar[i])) {
err = PTR_ERR(prz_ar[i]);
dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
name, record_size,
(unsigned long long)*paddr, err);
while (i > 0) {
i--;
persistent_ram_free(&prz_ar[i]);
}
kfree(prz_ar);
prz_ar = NULL;
goto fail;
}
*paddr += zone_sz;
prz_ar[i]->type = pstore_name_to_type(name);
}
*przs = prz_ar;
return 0;
fail:
*cnt = 0;
return err;
}
static int ramoops_init_prz(const char *name,
struct device *dev, struct ramoops_context *cxt,
struct persistent_ram_zone **prz,
phys_addr_t *paddr, size_t sz, u32 sig)
{
char *label;
if (!sz)
return 0;
if (*paddr + sz - cxt->phys_addr > cxt->size) {
dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
name, sz, (unsigned long long)*paddr,
cxt->size, (unsigned long long)cxt->phys_addr);
return -ENOMEM;
}
label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
kfree(label);
if (IS_ERR(*prz)) {
int err = PTR_ERR(*prz);
dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
name, sz, (unsigned long long)*paddr, err);
return err;
}
*paddr += sz;
(*prz)->type = pstore_name_to_type(name);
return 0;
}
/* Read a u32 from a dt property and make sure it's safe for an int. */
static int ramoops_parse_dt_u32(struct platform_device *pdev,
const char *propname,
u32 default_value, u32 *value)
{
u32 val32 = 0;
int ret;
ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
if (ret == -EINVAL) {
/* field is missing, use default value. */
val32 = default_value;
} else if (ret < 0) {
dev_err(&pdev->dev, "failed to parse property %s: %d\n",
propname, ret);
return ret;
}
/* Sanity check our results. */
if (val32 > INT_MAX) {
dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
return -EOVERFLOW;
}
*value = val32;
return 0;
}
static int ramoops_parse_dt(struct platform_device *pdev,
struct ramoops_platform_data *pdata)
{
struct device_node *of_node = pdev->dev.of_node;
struct device_node *parent_node;
struct resource *res;
u32 value;
int ret;
dev_dbg(&pdev->dev, "using Device Tree\n");
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev,
"failed to locate DT /reserved-memory resource\n");
return -EINVAL;
}
pdata->mem_size = resource_size(res);
pdata->mem_address = res->start;
/*
* Setting "unbuffered" is deprecated and will be ignored if
* "mem_type" is also specified.
*/
pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
/*
* Setting "no-dump-oops" is deprecated and will be ignored if
* "max_reason" is also specified.
*/
if (of_property_read_bool(of_node, "no-dump-oops"))
pdata->max_reason = KMSG_DUMP_PANIC;
else
pdata->max_reason = KMSG_DUMP_OOPS;
#define parse_u32(name, field, default_value) { \
ret = ramoops_parse_dt_u32(pdev, name, default_value, \
&value); \
if (ret < 0) \
return ret; \
field = value; \
}
parse_u32("mem-type", pdata->mem_type, pdata->mem_type);
parse_u32("record-size", pdata->record_size, 0);
parse_u32("console-size", pdata->console_size, 0);
parse_u32("ftrace-size", pdata->ftrace_size, 0);
parse_u32("pmsg-size", pdata->pmsg_size, 0);
parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);
parse_u32("flags", pdata->flags, 0);
parse_u32("max-reason", pdata->max_reason, pdata->max_reason);
#undef parse_u32
/*
* Some old Chromebooks relied on the kernel setting the
* console_size and pmsg_size to the record size since that's
* what the downstream kernel did. These same Chromebooks had
* "ramoops" straight under the root node which isn't
* according to the current upstream bindings (though it was
* arguably acceptable under a prior version of the bindings).
* Let's make those old Chromebooks work by detecting that
* we're not a child of "reserved-memory" and mimicking the
* expected behavior.
*/
parent_node = of_get_parent(of_node);
if (!of_node_name_eq(parent_node, "reserved-memory") &&
!pdata->console_size && !pdata->ftrace_size &&
!pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
pdata->console_size = pdata->record_size;
pdata->pmsg_size = pdata->record_size;
}
of_node_put(parent_node);
return 0;
}
static int ramoops_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ramoops_platform_data *pdata = dev->platform_data;
struct ramoops_platform_data pdata_local;
struct ramoops_context *cxt = &oops_cxt;
size_t dump_mem_sz;
phys_addr_t paddr;
int err = -EINVAL;
/*
* Only a single ramoops area allowed at a time, so fail extra
* probes.
*/
if (cxt->max_dump_cnt) {
pr_err("already initialized\n");
goto fail_out;
}
if (dev_of_node(dev) && !pdata) {
pdata = &pdata_local;
memset(pdata, 0, sizeof(*pdata));
err = ramoops_parse_dt(pdev, pdata);
if (err < 0)
goto fail_out;
}
/* Make sure we didn't get bogus platform data pointer. */
if (!pdata) {
pr_err("NULL platform data\n");
err = -EINVAL;
goto fail_out;
}
if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
!pdata->ftrace_size && !pdata->pmsg_size)) {
pr_err("The memory size and the record/console size must be "
"non-zero\n");
err = -EINVAL;
goto fail_out;
}
if (pdata->record_size && !is_power_of_2(pdata->record_size))
pdata->record_size = rounddown_pow_of_two(pdata->record_size);
if (pdata->console_size && !is_power_of_2(pdata->console_size))
pdata->console_size = rounddown_pow_of_two(pdata->console_size);
if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
cxt->size = pdata->mem_size;
cxt->phys_addr = pdata->mem_address;
cxt->memtype = pdata->mem_type;
cxt->record_size = pdata->record_size;
cxt->console_size = pdata->console_size;
cxt->ftrace_size = pdata->ftrace_size;
cxt->pmsg_size = pdata->pmsg_size;
cxt->flags = pdata->flags;
cxt->ecc_info = pdata->ecc_info;
paddr = cxt->phys_addr;
dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
- cxt->pmsg_size;
err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
dump_mem_sz, cxt->record_size,
&cxt->max_dump_cnt, 0, 0);
if (err)
goto fail_init;
err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
cxt->console_size, 0);
if (err)
goto fail_init;
err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
cxt->pmsg_size, 0);
if (err)
goto fail_init;
cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
? nr_cpu_ids
: 1;
err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
cxt->ftrace_size, -1,
&cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
? PRZ_FLAG_NO_LOCK : 0);
if (err)
goto fail_init;
cxt->pstore.data = cxt;
/*
* Prepare frontend flags based on which areas are initialized.
* For ramoops_init_przs() cases, the "max count" variable tells
* if there are regions present. For ramoops_init_prz() cases,
* the single region size is how to check.
*/
cxt->pstore.flags = 0;
if (cxt->max_dump_cnt) {
cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
cxt->pstore.max_reason = pdata->max_reason;
}
if (cxt->console_size)
cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
if (cxt->max_ftrace_cnt)
cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
if (cxt->pmsg_size)
cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
/*
* Since bufsize is only used for dmesg crash dumps, it
* must match the size of the dprz record (after PRZ header
* and ECC bytes have been accounted for).
*/
if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
cxt->pstore.buf = kvzalloc(cxt->pstore.bufsize, GFP_KERNEL);
if (!cxt->pstore.buf) {
pr_err("cannot allocate pstore crash dump buffer\n");
err = -ENOMEM;
goto fail_clear;
}
}
err = pstore_register(&cxt->pstore);
if (err) {
pr_err("registering with pstore failed\n");
goto fail_buf;
}
/*
* Update the module parameter variables as well so they are visible
* through /sys/module/ramoops/parameters/
*/
mem_size = pdata->mem_size;
mem_address = pdata->mem_address;
record_size = pdata->record_size;
ramoops_max_reason = pdata->max_reason;
ramoops_console_size = pdata->console_size;
ramoops_pmsg_size = pdata->pmsg_size;
ramoops_ftrace_size = pdata->ftrace_size;
pr_info("using 0x%lx@0x%llx, ecc: %d\n",
cxt->size, (unsigned long long)cxt->phys_addr,
cxt->ecc_info.ecc_size);
return 0;
fail_buf:
kvfree(cxt->pstore.buf);
fail_clear:
cxt->pstore.bufsize = 0;
fail_init:
ramoops_free_przs(cxt);
fail_out:
return err;
}
static void ramoops_remove(struct platform_device *pdev)
{
struct ramoops_context *cxt = &oops_cxt;
pstore_unregister(&cxt->pstore);
kvfree(cxt->pstore.buf);
cxt->pstore.bufsize = 0;
ramoops_free_przs(cxt);
}
static const struct of_device_id dt_match[] = {
{ .compatible = "ramoops" },
{}
};
MODULE_DEVICE_TABLE(of, dt_match);
static struct platform_driver ramoops_driver = {
.probe = ramoops_probe,
.remove_new = ramoops_remove,
.driver = {
.name = "ramoops",
.of_match_table = dt_match,
},
};
static inline void ramoops_unregister_dummy(void)
{
platform_device_unregister(dummy);
dummy = NULL;
}
static void __init ramoops_register_dummy(void)
{
struct ramoops_platform_data pdata;
/*
* Prepare a dummy platform data structure to carry the module
* parameters. If mem_size isn't set, then there are no module
* parameters, and we can skip this.
*/
if (!mem_size)
return;
pr_info("using module parameters\n");
memset(&pdata, 0, sizeof(pdata));
pdata.mem_size = mem_size;
pdata.mem_address = mem_address;
pdata.mem_type = mem_type;
pdata.record_size = record_size;
pdata.console_size = ramoops_console_size;
pdata.ftrace_size = ramoops_ftrace_size;
pdata.pmsg_size = ramoops_pmsg_size;
/* If "max_reason" is set, its value has priority over "dump_oops". */
if (ramoops_max_reason >= 0)
pdata.max_reason = ramoops_max_reason;
/* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
else if (ramoops_dump_oops != -1)
pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
: KMSG_DUMP_PANIC;
/* And if neither are explicitly set, use the default. */
else
pdata.max_reason = KMSG_DUMP_OOPS;
pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
/*
* For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
* (using 1 byte for ECC isn't much of use anyway).
*/
pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
dummy = platform_device_register_data(NULL, "ramoops", -1,
&pdata, sizeof(pdata));
if (IS_ERR(dummy)) {
pr_info("could not create platform device: %ld\n",
PTR_ERR(dummy));
dummy = NULL;
}
}
static int __init ramoops_init(void)
{
int ret;
ramoops_register_dummy();
ret = platform_driver_register(&ramoops_driver);
if (ret != 0)
ramoops_unregister_dummy();
return ret;
}
postcore_initcall(ramoops_init);
static void __exit ramoops_exit(void)
{
platform_driver_unregister(&ramoops_driver);
ramoops_unregister_dummy();
}
module_exit(ramoops_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");