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Commit 9d5438f4 authored by Mark Salyzyn's avatar Mark Salyzyn Committed by Tony Luck
Browse files

pstore: Add pmsg - user-space accessible pstore object 



A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available in
/sys/fs/pstore/pmsg-ramoops-[ID].

One possible use is syslogd, or other daemon, can
write messages, then on reboot provides a means to
triage user-space activities leading up to a panic
as a companion to the pstore dmesg or console logs.

Signed-off-by: default avatarMark Salyzyn <salyzyn@android.com>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent f44f9652

fs/pstore/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -21,6 +21,16 @@ config PSTORE_CONSOLE 
	  When the option is enabled, pstore will log all kernel

	  messages, even if no oops or panic happened.



config PSTORE_PMSG

	bool "Log user space messages"

	depends on PSTORE

	help

	  When the option is enabled, pstore will export a character

	  interface /dev/pmsg0 to log user space messages. On reboot

	  data can be retrieved from /sys/fs/pstore/pmsg-ramoops-[ID].



	  If unsure, say N.



config PSTORE_FTRACE

	bool "Persistent function tracer"

	depends on PSTORE

fs/pstore/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -7,5 +7,7 @@ obj-y += pstore.o 
pstore-objs += inode.o platform.o

obj-$(CONFIG_PSTORE_FTRACE)	+= ftrace.o



obj-$(CONFIG_PSTORE_PMSG)	+= pmsg.o



ramoops-objs += ram.o ram_core.o

obj-$(CONFIG_PSTORE_RAM)	+= ramoops.o

fs/pstore/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -361,6 +361,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count, 
		scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",

			  psname, id);

		break;

	case PSTORE_TYPE_PMSG:

		scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id);

		break;

	case PSTORE_TYPE_UNKNOWN:

		scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);

		break;

fs/pstore/internal.h

+6 −0
Original line number Diff line number Diff line
@@ -45,6 +45,12 @@ extern void pstore_register_ftrace(void); 
static inline void pstore_register_ftrace(void) {}

#endif



#ifdef CONFIG_PSTORE_PMSG

extern void pstore_register_pmsg(void);

#else

static inline void pstore_register_pmsg(void) {}

#endif



extern struct pstore_info *psinfo;



extern void	pstore_set_kmsg_bytes(int);

fs/pstore/platform.c

+1 −0
Original line number Diff line number Diff line
@@ -447,6 +447,7 @@ int pstore_register(struct pstore_info *psi) 
	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {

		pstore_register_console();

		pstore_register_ftrace();

		pstore_register_pmsg();

	}



	if (pstore_update_ms >= 0) {