Commit 182ca6e0 authored by Yue Hu's avatar Yue Hu Committed by Kees Cook
Browse files

pstore/ram: Replace dummy_data heap memory with stack memory 



In ramoops_register_dummy() dummy_data is allocated via kzalloc()
then it will always occupy the heap space after register platform
device via platform_device_register_data(), but it will not be
used any more. So let's free it for system usage, replace it with
stack memory is better due to small size.

Signed-off-by: default avatarYue Hu <huyue2@yulong.com>
[kees: add required memset and adjust sizeof() argument]
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 49a57857

fs/pstore/ram.c

+14 −21
Original line number Diff line number Diff line
@@ -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)

{
@@ -892,13 +891,12 @@ 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 +907,25 @@ 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));

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