pstore cleanups

- Remove some needless memory allocations (Yue Hu, Kees Cook)
 - Add zero-length checks to avoid no-op calls (Yue Hu)
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Merge tag 'pstore-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore cleanups from Kees Cook:

 - Remove some needless memory allocations (Yue Hu, Kees Cook)

 - Add zero-length checks to avoid no-op calls (Yue Hu)

* tag 'pstore-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Avoid needless alloc during header write
  pstore/ram: Add kmsg hlen zero check to ramoops_pstore_write()
  pstore/ram: Move initialization earlier
  pstore: Avoid writing records with zero size
  pstore/ram: Replace dummy_data heap memory with stack memory
This commit is contained in:
Linus Torvalds 2019-03-09 09:02:47 -08:00
commit a39f009ace
2 changed files with 32 additions and 35 deletions

View File

@ -501,6 +501,9 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
{
struct pstore_record record;
if (!c)
return;
pstore_record_init(&record, psinfo);
record.type = PSTORE_TYPE_CONSOLE;

View File

@ -110,7 +110,6 @@ struct ramoops_context {
};
static struct platform_device *dummy;
static struct ramoops_platform_data *dummy_data;
static int ramoops_pstore_open(struct pstore_info *psi)
{
@ -346,17 +345,15 @@ out:
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
struct pstore_record *record)
{
char *hdr;
char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
size_t len;
hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
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');
WARN_ON_ONCE(!hdr);
len = hdr ? strlen(hdr) : 0;
persistent_ram_write(prz, hdr, len);
kfree(hdr);
return len;
}
@ -424,6 +421,9 @@ static int notrace ramoops_pstore_write(struct pstore_record *record)
/* 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;
@ -716,15 +716,6 @@ static int ramoops_probe(struct platform_device *pdev)
phys_addr_t paddr;
int err = -EINVAL;
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;
}
/*
* Only a single ramoops area allowed at a time, so fail extra
* probes.
@ -734,6 +725,15 @@ static int ramoops_probe(struct platform_device *pdev)
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");
@ -892,13 +892,12 @@ static inline void ramoops_unregister_dummy(void)
{
platform_device_unregister(dummy);
dummy = NULL;
kfree(dummy_data);
dummy_data = 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
@ -909,30 +908,25 @@ static void __init ramoops_register_dummy(void)
pr_info("using module parameters\n");
dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
if (!dummy_data) {
pr_info("could not allocate pdata\n");
return;
}
dummy_data->mem_size = mem_size;
dummy_data->mem_address = mem_address;
dummy_data->mem_type = mem_type;
dummy_data->record_size = record_size;
dummy_data->console_size = ramoops_console_size;
dummy_data->ftrace_size = ramoops_ftrace_size;
dummy_data->pmsg_size = ramoops_pmsg_size;
dummy_data->dump_oops = dump_oops;
dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
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;
pdata.dump_oops = 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).
*/
dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
dummy = platform_device_register_data(NULL, "ramoops", -1,
dummy_data, sizeof(struct ramoops_platform_data));
&pdata, sizeof(pdata));
if (IS_ERR(dummy)) {
pr_info("could not create platform device: %ld\n",
PTR_ERR(dummy));