diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 11 | ||||
| -rw-r--r-- | fs/proc/Kconfig | 3 | ||||
| -rw-r--r-- | fs/proc/vmcore.c | 9 |
3 files changed, 22 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f8b62360b18c..bf8221abfe0a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2877,6 +2877,17 @@ /sys/module/printk/parameters/console_suspend) to turn on/off it dynamically. + novmcoredd [KNL,KDUMP] + Disable device dump. Device dump allows drivers to + append dump data to vmcore so you can collect driver + specified debug info. Drivers can append the data + without any limit and this data is stored in memory, + so this may cause significant memory stress. Disabling + device dump can help save memory but the driver debug + data will be no longer available. This parameter + is only available when CONFIG_PROC_VMCORE_DEVICE_DUMP + is set. + noaliencache [MM, NUMA, SLAB] Disables the allocation of alien caches in the slab allocator. Saves per-node memory, but will impact performance. diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index 4c3dcb718961..cba429db95d9 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -58,7 +58,8 @@ config PROC_VMCORE_DEVICE_DUMP snapshot. If you say Y here, the collected device dumps will be added - as ELF notes to /proc/vmcore. + as ELF notes to /proc/vmcore. You can still disable device + dump using the kernel command line option 'novmcoredd'. config PROC_SYSCTL bool "Sysctl support (/proc/sys)" if EXPERT diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 57957c91c6df..7bcc92add72c 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -21,6 +21,7 @@ #include <linux/init.h> #include <linux/crash_dump.h> #include <linux/list.h> +#include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/vmalloc.h> #include <linux/pagemap.h> @@ -54,6 +55,9 @@ static struct proc_dir_entry *proc_vmcore; /* Device Dump list and mutex to synchronize access to list */ static LIST_HEAD(vmcoredd_list); static DEFINE_MUTEX(vmcoredd_mutex); + +static bool vmcoredd_disabled; +core_param(novmcoredd, vmcoredd_disabled, bool, 0); #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ /* Device Dump Size */ @@ -1452,6 +1456,11 @@ int vmcore_add_device_dump(struct vmcoredd_data *data) size_t data_size; int ret; + if (vmcoredd_disabled) { + pr_err_once("Device dump is disabled\n"); + return -EINVAL; + } + if (!data || !strlen(data->dump_name) || !data->vmcoredd_callback || !data->size) return -EINVAL; |