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Date:   Fri, 8 May 2020 08:11:24 +0200
From:   Daniel Vetter <daniel@ffwll.ch>
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     jeyu@kernel.org, akpm@linux-foundation.org, arnd@arndb.de,
        rostedt@goodmis.org, mingo@redhat.com, aquini@redhat.com,
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        pmladek@suse.com, tiwai@suse.de, schlad@suse.de,
        andriy.shevchenko@linux.intel.com, keescook@chromium.org,
        daniel.vetter@ffwll.ch, will@kernel.org,
        mchehab+samsung@kernel.org, kvalo@codeaurora.org,
        davem@davemloft.net, linux-kernel@vger.kernel.org
Subject: Re: [RFC] taint: add module firmware crash taint support
Message-ID: <20200508061124.GZ10381@phenom.ffwll.local>
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On Fri, May 08, 2020 at 02:14:38AM +0000, Luis Chamberlain wrote:
> Device driver firmware can crash, and sometimes, this can leave your
> system in a state which makes the device or subsystem completely
> useless. Detecting this by inspecting /proc/sys/kernel/tainted instead
> of scraping some magical words from the kernel log, which is driver
> specific, is much easier. So instead provide a helper which lets drivers
> annotate this.
> 
> Once this happens, scrapers can easily scrape modules taint flags.
> This will taint both the kernel and respective calling module.
> 
> The new helper module_firmware_crashed() uses LOCKDEP_STILL_OK as
> this fact should in no way shape or form affect lockdep. This taint
> is device driver specific.
> 
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> ---
> 
> Below is the full diff stat of manual inspection throughout the kernel
> when this happens. My methodology is to just scrape for "crash" and
> then study the driver a bit to see if indeed it seems like that the
> firmware crashes there. In *many* cases there is even infrastructure
> for this, so this is sometimes clearly obvious. Some other times it
> required a bit of deciphering.
> 
> The diff stat below is what I have so far, however the patch below
> only includes the drivers that start with Q, as they were a source of
> inspiration for this, and to make this RFC easier to read.
> 
> If this seems sensible, I can follow up with the kernel helper first,
> and then tackle each subsystem independently.
> 
> I purposely skipped review of remoteproc and virtualization. That should
> require its own separate careful review and considerations.
> 
>  drivers/atm/nicstar.c                               |  1 +
>  drivers/bluetooth/hci_qca.c                         |  1 +
>  drivers/gpu/drm/i915/i915_gpu_error.c               |  1 +
>  drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c         |  2 ++
>  drivers/gpu/drm/msm/msm_gpu.c                       |  1 +

I'm not finding the drm changes in your diff below ... Also what Kees
said, I think best to split this up and properly cc per
get_maintainers.pl.
-Daniel

>  drivers/media/dvb-frontends/sp8870.c                |  1 +
>  drivers/media/pci/ttpci/av7110.c                    |  1 +
>  drivers/misc/mic/cosm/cosm_scif_server.c            |  1 +
>  drivers/net/ethernet/8390/axnet_cs.c                |  4 +++-
>  drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c    |  1 +
>  drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c   |  1 +
>  drivers/net/ethernet/brocade/bna/bfa_ioc.c          |  1 +
>  drivers/net/ethernet/cavium/liquidio/lio_main.c     |  1 +
>  drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c     |  1 +
>  drivers/net/ethernet/ibm/ehea/ehea_main.c           |  2 ++
>  drivers/net/ethernet/qlogic/qed/qed_debug.c         |  3 +++
>  drivers/net/ipa/ipa_modem.c                         |  1 +
>  drivers/net/wimax/i2400m/rx.c                       |  1 +
>  drivers/net/wireless/ath/ath10k/pci.c               |  2 ++
>  drivers/net/wireless/ath/ath10k/sdio.c              |  2 ++
>  drivers/net/wireless/ath/ath10k/snoc.c              |  1 +
>  drivers/net/wireless/ath/ath6kl/hif.c               |  1 +
>  .../net/wireless/broadcom/brcm80211/brcmfmac/core.c |  1 +
>  drivers/net/wireless/marvell/mwl8k.c                |  1 +
>  drivers/scsi/bfa/bfa_ioc.c                          |  1 +
>  drivers/scsi/megaraid/megaraid_sas_fusion.c         |  1 +
>  drivers/scsi/qla4xxx/ql4_mbx.c                      |  2 ++
>  drivers/staging/media/omap4iss/iss.c                |  1 +
>  include/linux/kernel.h                              |  3 ++-
>  include/linux/module.h                              | 13 +++++++++++++
>  include/trace/events/module.h                       |  3 ++-
>  kernel/module.c                                     |  5 +++--
>  kernel/panic.c                                      |  1 +
>  33 files changed, 58 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/qlogic/qed/qed_debug.c b/drivers/net/ethernet/qlogic/qed/qed_debug.c
> index f4eebaabb6d0..9cc6287b889b 100644
> --- a/drivers/net/ethernet/qlogic/qed/qed_debug.c
> +++ b/drivers/net/ethernet/qlogic/qed/qed_debug.c
> @@ -7854,6 +7854,7 @@ int qed_dbg_all_data(struct qed_dev *cdev, void *buffer)
>  						 REGDUMP_HEADER_SIZE,
>  						 &feature_size);
>  		if (!rc) {
> +			module_firmware_crashed();
>  			*(u32 *)((u8 *)buffer + offset) =
>  			    qed_calc_regdump_header(cdev, PROTECTION_OVERRIDE,
>  						    cur_engine,
> @@ -7869,6 +7870,7 @@ int qed_dbg_all_data(struct qed_dev *cdev, void *buffer)
>  		rc = qed_dbg_fw_asserts(cdev, (u8 *)buffer + offset +
>  					REGDUMP_HEADER_SIZE, &feature_size);
>  		if (!rc) {
> +			module_firmware_crashed();
>  			*(u32 *)((u8 *)buffer + offset) =
>  			    qed_calc_regdump_header(cdev, FW_ASSERTS,
>  						    cur_engine, feature_size,
> @@ -7906,6 +7908,7 @@ int qed_dbg_all_data(struct qed_dev *cdev, void *buffer)
>  		rc = qed_dbg_grc(cdev, (u8 *)buffer + offset +
>  				 REGDUMP_HEADER_SIZE, &feature_size);
>  		if (!rc) {
> +			module_firmware_crashed();
>  			*(u32 *)((u8 *)buffer + offset) =
>  			    qed_calc_regdump_header(cdev, GRC_DUMP,
>  						    cur_engine,
> diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
> index 1d941d53fdc9..6bd0f3b518b9 100644
> --- a/drivers/net/wireless/ath/ath10k/pci.c
> +++ b/drivers/net/wireless/ath/ath10k/pci.c
> @@ -1767,6 +1767,7 @@ static void ath10k_pci_fw_dump_work(struct work_struct *work)
>  		scnprintf(guid, sizeof(guid), "n/a");
>  
>  	ath10k_err(ar, "firmware crashed! (guid %s)\n", guid);
> +	module_firmware_crashed();
>  	ath10k_print_driver_info(ar);
>  	ath10k_pci_dump_registers(ar, crash_data);
>  	ath10k_ce_dump_registers(ar, crash_data);
> @@ -2837,6 +2838,7 @@ static int ath10k_pci_hif_power_up(struct ath10k *ar,
>  	if (ret) {
>  		if (ath10k_pci_has_fw_crashed(ar)) {
>  			ath10k_warn(ar, "firmware crashed during chip reset\n");
> +			module_firmware_crashed();
>  			ath10k_pci_fw_crashed_clear(ar);
>  			ath10k_pci_fw_crashed_dump(ar);
>  		}
> diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
> index e2aff2254a40..d34ad289380f 100644
> --- a/drivers/net/wireless/ath/ath10k/sdio.c
> +++ b/drivers/net/wireless/ath/ath10k/sdio.c
> @@ -794,6 +794,7 @@ static int ath10k_sdio_mbox_proc_dbg_intr(struct ath10k *ar)
>  
>  	/* TODO: Add firmware crash handling */
>  	ath10k_warn(ar, "firmware crashed\n");
> +	module_firmware_crashed();
>  
>  	/* read counter to clear the interrupt, the debug error interrupt is
>  	 * counter 0.
> @@ -915,6 +916,7 @@ static int ath10k_sdio_mbox_proc_cpu_intr(struct ath10k *ar)
>  	if (cpu_int_status & MBOX_CPU_STATUS_ENABLE_ASSERT_MASK) {
>  		ath10k_err(ar, "firmware crashed!\n");
>  		queue_work(ar->workqueue, &ar->restart_work);
> +		module_firmware_crashed();
>  	}
>  	return ret;
>  }
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
> index 354d49b1cd45..7cfc123c345c 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -1451,6 +1451,7 @@ void ath10k_snoc_fw_crashed_dump(struct ath10k *ar)
>  		scnprintf(guid, sizeof(guid), "n/a");
>  
>  	ath10k_err(ar, "firmware crashed! (guid %s)\n", guid);
> +	module_firmware_crashed();
>  	ath10k_print_driver_info(ar);
>  	ath10k_msa_dump_memory(ar, crash_data);
>  	mutex_unlock(&ar->dump_mutex);
> diff --git a/drivers/net/wireless/ath/ath6kl/hif.c b/drivers/net/wireless/ath/ath6kl/hif.c
> index d1942537ea10..cfd838607544 100644
> --- a/drivers/net/wireless/ath/ath6kl/hif.c
> +++ b/drivers/net/wireless/ath/ath6kl/hif.c
> @@ -120,6 +120,7 @@ static int ath6kl_hif_proc_dbg_intr(struct ath6kl_device *dev)
>  	int ret;
>  
>  	ath6kl_warn("firmware crashed\n");
> +	module_firmware_crashed();
>  
>  	/*
>  	 * read counter to clear the interrupt, the debug error interrupt is
> diff --git a/drivers/scsi/qla4xxx/ql4_mbx.c b/drivers/scsi/qla4xxx/ql4_mbx.c
> index 02636b4785c5..39a58ba5df0a 100644
> --- a/drivers/scsi/qla4xxx/ql4_mbx.c
> +++ b/drivers/scsi/qla4xxx/ql4_mbx.c
> @@ -1016,6 +1016,8 @@ void qla4xxx_get_crash_record(struct scsi_qla_host * ha)
>  	dma_addr_t crash_record_dma = 0;
>  	uint32_t crash_record_size = 0;
>  
> +	module_firmware_crashed();
> +
>  	memset(&mbox_cmd, 0, sizeof(mbox_cmd));
>  	memset(&mbox_sts, 0, sizeof(mbox_cmd));
>  
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 04a5885cec1b..19e1541c82c7 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -601,7 +601,8 @@ extern enum system_states {
>  #define TAINT_LIVEPATCH			15
>  #define TAINT_AUX			16
>  #define TAINT_RANDSTRUCT		17
> -#define TAINT_FLAGS_COUNT		18
> +#define TAINT_FIRMWARE_CRASH		18
> +#define TAINT_FLAGS_COUNT		19
>  
>  struct taint_flag {
>  	char c_true;	/* character printed when tainted */
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 1ad393e62bef..de9156dfe6bb 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -697,6 +697,14 @@ static inline bool is_livepatch_module(struct module *mod)
>  bool is_module_sig_enforced(void);
>  void set_module_sig_enforced(void);
>  
> +void add_taint_module(struct module *mod, unsigned flag,
> +		      enum lockdep_ok lockdep_ok);
> +
> +static inline void module_firmware_crashed(void)
> +{
> +	add_taint_module(THIS_MODULE, TAINT_FIRMWARE_CRASH, LOCKDEP_STILL_OK);
> +}
> +
>  #else /* !CONFIG_MODULES... */
>  
>  static inline struct module *__module_address(unsigned long addr)
> @@ -844,6 +852,11 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
>  	return ptr;
>  }
>  
> +static inline void module_firmware_crashed(void)
> +{
> +	add_taint(TAINT_FIRMWARE_CRASH, val);
> +}
> +
>  #endif /* CONFIG_MODULES */
>  
>  #ifdef CONFIG_SYSFS
> diff --git a/include/trace/events/module.h b/include/trace/events/module.h
> index 097485c73c01..b749ea25affd 100644
> --- a/include/trace/events/module.h
> +++ b/include/trace/events/module.h
> @@ -26,7 +26,8 @@ struct module;
>  	{ (1UL << TAINT_OOT_MODULE),		"O" },		\
>  	{ (1UL << TAINT_FORCED_MODULE),		"F" },		\
>  	{ (1UL << TAINT_CRAP),			"C" },		\
> -	{ (1UL << TAINT_UNSIGNED_MODULE),	"E" })
> +	{ (1UL << TAINT_UNSIGNED_MODULE),	"E" },		\
> +	{ (1UL << TAINT_FIRMWARE_CRASH),	"Q" })
>  
>  TRACE_EVENT(module_load,
>  
> diff --git a/kernel/module.c b/kernel/module.c
> index d626dc31b37f..06e6e645dbd4 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -325,12 +325,13 @@ static inline int strong_try_module_get(struct module *mod)
>  		return -ENOENT;
>  }
>  
> -static inline void add_taint_module(struct module *mod, unsigned flag,
> -				    enum lockdep_ok lockdep_ok)
> +void add_taint_module(struct module *mod, unsigned flag,
> +		      enum lockdep_ok lockdep_ok)
>  {
>  	add_taint(flag, lockdep_ok);
>  	set_bit(flag, &mod->taints);
>  }
> +EXPORT_SYMBOL_GPL(add_taint_module);
>  
>  /*
>   * A thread that wants to hold a reference to a module only while it
> diff --git a/kernel/panic.c b/kernel/panic.c
> index ec6d7d788ce7..504fb926947e 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -384,6 +384,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
>  	[ TAINT_LIVEPATCH ]		= { 'K', ' ', true },
>  	[ TAINT_AUX ]			= { 'X', ' ', true },
>  	[ TAINT_RANDSTRUCT ]		= { 'T', ' ', true },
> +	[ TAINT_FIRMWARE_CRASH ]	= { 'Q', ' ', true },
>  };
>  
>  /**
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch