From a7c561f2e32f98b477f5fe670b3f294be6b1eae2 Mon Sep 17 00:00:00 2001 From: Thomas Klein Date: Tue, 20 Apr 2010 23:11:31 +0000 Subject: [PATCH] ehea: fix possible DLPAR/mem deadlock Force serialization of userspace-triggered DLPAR/mem operations Signed-off-by: Thomas Klein Signed-off-by: David S. Miller --- drivers/net/ehea/ehea.h | 2 +- drivers/net/ehea/ehea_main.c | 19 ++++++++++++++----- 2 files changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/net/ehea/ehea.h b/drivers/net/ehea/ehea.h index fa311a950996..0630980a2722 100644 --- a/drivers/net/ehea/ehea.h +++ b/drivers/net/ehea/ehea.h @@ -40,7 +40,7 @@ #include #define DRV_NAME "ehea" -#define DRV_VERSION "EHEA_0102" +#define DRV_VERSION "EHEA_0103" /* eHEA capability flags */ #define DLPAR_PORT_ADD_REM 1 diff --git a/drivers/net/ehea/ehea_main.c b/drivers/net/ehea/ehea_main.c index c35d1e3631d1..39774817c3eb 100644 --- a/drivers/net/ehea/ehea_main.c +++ b/drivers/net/ehea/ehea_main.c @@ -2889,7 +2889,6 @@ static void ehea_rereg_mrs(struct work_struct *work) int ret, i; struct ehea_adapter *adapter; - mutex_lock(&dlpar_mem_lock); ehea_info("LPAR memory changed - re-initializing driver"); list_for_each_entry(adapter, &adapter_list, list) @@ -2959,7 +2958,6 @@ static void ehea_rereg_mrs(struct work_struct *work) } ehea_info("re-initializing driver complete"); out: - mutex_unlock(&dlpar_mem_lock); return; } @@ -3542,7 +3540,14 @@ void ehea_crash_handler(void) static int ehea_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) { + int ret = NOTIFY_BAD; struct memory_notify *arg = data; + + if (!mutex_trylock(&dlpar_mem_lock)) { + ehea_info("ehea_mem_notifier must not be called parallelized"); + goto out; + } + switch (action) { case MEM_CANCEL_OFFLINE: ehea_info("memory offlining canceled"); @@ -3551,14 +3556,14 @@ static int ehea_mem_notifier(struct notifier_block *nb, ehea_info("memory is going online"); set_bit(__EHEA_STOP_XFER, &ehea_driver_flags); if (ehea_add_sect_bmap(arg->start_pfn, arg->nr_pages)) - return NOTIFY_BAD; + goto out_unlock; ehea_rereg_mrs(NULL); break; case MEM_GOING_OFFLINE: ehea_info("memory is going offline"); set_bit(__EHEA_STOP_XFER, &ehea_driver_flags); if (ehea_rem_sect_bmap(arg->start_pfn, arg->nr_pages)) - return NOTIFY_BAD; + goto out_unlock; ehea_rereg_mrs(NULL); break; default: @@ -3566,8 +3571,12 @@ static int ehea_mem_notifier(struct notifier_block *nb, } ehea_update_firmware_handles(); + ret = NOTIFY_OK; - return NOTIFY_OK; +out_unlock: + mutex_unlock(&dlpar_mem_lock); +out: + return ret; } static struct notifier_block ehea_mem_nb = { -- 2.20.1