linux/drivers/edac
Robert Richter 16214bd9e4 EDAC/ghes: Do not warn when incrementing refcount on 0
The following warning from the refcount framework is seen during ghes
initialization:

  EDAC MC0: Giving out device to module ghes_edac.c controller ghes_edac: DEV ghes (INTERRUPT)
  ------------[ cut here ]------------
  refcount_t: increment on 0; use-after-free.
  WARNING: CPU: 36 PID: 1 at lib/refcount.c:156 refcount_inc_checked
 [...]
  Call trace:
   refcount_inc_checked
   ghes_edac_register
   ghes_probe
   ...

It warns if the refcount is incremented from zero. This warning is
reasonable as a kernel object is typically created with a refcount of
one and freed once the refcount is zero. Afterwards the object would be
"used-after-free".

For GHES, the refcount is initialized with zero, and that is why this
message is seen when initializing the first instance. However, whenever
the refcount is zero, the device will be allocated and registered. Since
the ghes_reg_mutex protects the refcount and serializes allocation and
freeing of ghes devices, a use-after-free cannot happen here.

Instead of using refcount_inc() for the first instance, use
refcount_set(). This can be used here because the refcount is zero at
this point and can not change due to its protection by the mutex.

Fixes: 23f61b9fc5 ("EDAC/ghes: Fix locking and memory barrier issues")
Reported-by: John Garry <john.garry@huawei.com>
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: John Garry <john.garry@huawei.com>
Cc: <huangming23@huawei.com>
Cc: James Morse <james.morse@arm.com>
Cc: <linuxarm@huawei.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: <tanxiaofei@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <wanghuiqiang@huawei.com>
Link: https://lkml.kernel.org/r/20191121213628.21244-1-rrichter@marvell.com
2019-11-22 09:53:08 +01:00
..
altera_edac.c EDAC/altera: Use the proper type for the IRQ status bits 2019-08-07 10:37:34 +02:00
altera_edac.h edac: altera: Move Stratix10 SDRAM ECC to peripheral 2019-07-25 14:28:42 -04:00
amd64_edac_dbg.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
amd64_edac_inj.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
amd64_edac.c EDAC/amd64: Get rid of the ECC disabled long message 2019-11-09 10:06:36 +01:00
amd64_edac.h EDAC/amd64: Save max number of controllers to family type 2019-11-06 11:07:01 +01:00
amd76x_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
amd8111_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
amd8111_edac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
amd8131_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
amd8131_edac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
armada_xp_edac.c ARM: 8891/1: EDAC: armada_xp: Add support for more SoCs 2019-08-29 07:58:01 +01:00
aspeed_edac.c EDAC/aspeed: Use devm_platform_ioremap_resource() in aspeed_probe() 2019-10-24 11:17:29 +02:00
bluefield_edac.c EDAC, mellanox: Add ECC support for BlueField DDR4 2019-08-08 12:57:01 -03:00
cell_edac.c edac: rename edac_core.h to edac_mc.h 2016-12-15 08:54:51 -02:00
cpc925_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
debugfs.c ARM: 8892/1: EDAC: Add missing debugfs_create_x32 wrapper 2019-08-29 07:58:01 +01:00
e7xxx_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
e752x_edac.c EDAC: Fix indentation issues in several EDAC drivers 2018-11-10 16:56:16 +01:00
edac_device_sysfs.c edac: move EDAC device definitions to drivers/edac/edac_device.h 2016-12-15 08:54:51 -02:00
edac_device.c EDAC/device: Rework error logging API 2019-10-09 13:01:42 +02:00
edac_device.h EDAC/device: Rework error logging API 2019-10-09 13:01:42 +02:00
edac_mc_sysfs.c EDAC: Introduce an mci_for_each_dimm() iterator 2019-11-10 12:39:40 +01:00
edac_mc.c EDAC: Unify the mc_event tracepoint call 2019-11-10 12:40:14 +01:00
edac_mc.h EDAC: Prefer 'unsigned int' to bare use of 'unsigned' 2019-09-03 19:21:19 +02:00
edac_module.c treewide: Fix function prototypes for module_param_call() 2017-10-31 15:30:37 +01:00
edac_module.h ARM: 8892/1: EDAC: Add missing debugfs_create_x32 wrapper 2019-08-29 07:58:01 +01:00
edac_pci_sysfs.c edac: move documentation from edac_pci*.c to edac_pci.h 2016-12-15 08:54:51 -02:00
edac_pci.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
edac_pci.h edac: move documentation from edac_pci*.c to edac_pci.h 2016-12-15 08:54:51 -02:00
fsl_ddr_edac.c EDAC, fsl_ddr: Add LS1021A to the list of supported hardware 2018-12-19 11:57:45 +01:00
fsl_ddr_edac.h EDAC, fsl_ddr: Add LS1021A to the list of supported hardware 2018-12-19 11:57:45 +01:00
ghes_edac.c EDAC/ghes: Do not warn when incrementing refcount on 0 2019-11-22 09:53:08 +01:00
highbank_l2_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
highbank_mc_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
i7core_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i10nm_base.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i3000_edac.c EDAC: Fix indentation issues in several EDAC drivers 2018-11-10 16:56:16 +01:00
i3200_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i5000_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i5100_edac.c EDAC: Introduce an mci_for_each_dimm() iterator 2019-11-10 12:39:40 +01:00
i5400_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i7300_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
i82443bxgx_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
i82860_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
i82875p_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
i82975x_edac.c EDAC, i82975x: Fix spelling mistake "reserverd" -> "reserved" 2018-11-20 17:46:01 +01:00
ie31200_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
Kconfig ARM updates for 5.4-rc1: 2019-09-22 09:39:09 -07:00
layerscape_edac.c edac: rename edac_core.h to edac_mc.h 2016-12-15 08:54:51 -02:00
Makefile ARM updates for 5.4-rc1: 2019-09-22 09:39:09 -07:00
mce_amd.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
mce_amd.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpc85xx_edac.c EDAC, mpc85xx: Add T2080 l2-cache support 2017-02-03 10:36:35 +01:00
mpc85xx_edac.h EDAC, fsl-ddr: Separate FSL DDR driver from MPC85xx 2016-09-01 10:28:00 +02:00
mv64x60_edac.c EDAC, mv64x60: Fix an error handling path 2018-01-09 20:14:23 +01:00
mv64x60_edac.h edac: Drop __DATE__ usage 2011-04-19 00:23:22 +02:00
octeon_edac-l2c.c edac: rename edac_core.h to edac_mc.h 2016-12-15 08:54:51 -02:00
octeon_edac-lmc.c EDAC, octeon: Fix an uninitialized variable warning 2017-11-27 11:57:26 +01:00
octeon_edac-pc.c edac: rename edac_core.h to edac_mc.h 2016-12-15 08:54:51 -02:00
octeon_edac-pci.c edac: rename edac_core.h to edac_mc.h 2016-12-15 08:54:51 -02:00
pasemi_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
pnd2_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
pnd2_edac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
ppc4xx_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
ppc4xx_edac.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
qcom_edac.c EDAC, qcom_edac: Remove irq_handled local variable 2018-11-06 12:03:16 +01:00
r82600_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
sb_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
sifive_edac.c EDAC/sifive: Add EDAC platform driver for SiFive SoCs 2019-06-20 11:44:36 -07:00
skx_base.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
skx_common.c EDAC, skx: Retrieve and print retry_rd_err_log registers 2019-10-18 15:27:58 -07:00
skx_common.h EDAC, skx: Retrieve and print retry_rd_err_log registers 2019-10-18 15:27:58 -07:00
synopsys_edac.c EDAC, synopsys: Add Error Injection support for ZynqMP DDR controller 2018-11-06 10:38:27 +01:00
thunderx_edac.c EDAC, thunderx: Fix memory leak in thunderx_l2c_threaded_isr() 2018-10-13 13:58:06 +02:00
ti_edac.c EDAC: Replace EDAC_DIMM_PTR() macro with edac_get_dimm() function 2019-11-09 10:32:32 +01:00
wq.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
x38_edac.c EDAC: Get rid of mci->mod_ver 2017-07-17 13:42:48 +02:00
xgene_edac.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00