From 182ca6e0ae23550cf98d05daeab8dcb7fdc0a928 Mon Sep 17 00:00:00 2001 From: Yue Hu Date: Mon, 21 Jan 2019 18:20:41 +0800 Subject: 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: Yue Hu [kees: add required memset and adjust sizeof() argument] Signed-off-by: Kees Cook --- fs/pstore/ram.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-) (limited to 'fs/pstore') diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 898c8321b343..1adb5e35c004 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -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)); -- cgit