linux/drivers/iommu
Arnd Bergmann 287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -07:00
..
amd_iommu_init.c iommu/amd: Introduces ivrs_acpihid kernel parameter 2016-04-07 13:29:41 +02:00
amd_iommu_proto.h IOMMU Updates for Linux v4.2 2015-06-23 18:27:19 -07:00
amd_iommu_types.h iommu/amd: Remove statistics code 2016-05-09 16:58:37 +02:00
amd_iommu_v2.c mm/core: Do not enforce PKEY permissions on remote mm access 2016-02-18 19:46:28 +01:00
amd_iommu.c IOMMU Updates for Linux v4.7 2016-05-19 17:07:04 -07:00
arm-smmu-v3.c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
arm-smmu.c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
dma-iommu.c iommu/dma: Finish optimising higher-order allocations 2016-05-09 15:33:29 +02:00
dmar.c iommu/vt-d: Improve fault handler error messages 2016-04-05 16:22:42 +02:00
exynos-iommu.c iommu/exynos: Use proper readl/writel register interface 2016-02-29 16:44:24 +01:00
fsl_pamu_domain.c iommu/fsl: Convert to device_group call-back 2015-10-22 00:00:49 +02:00
fsl_pamu_domain.h iommu/fsl: Make use of domain_alloc and domain_free 2015-03-31 15:32:14 +02:00
fsl_pamu.c powerpc/fsl: Move fsl_guts.h out of arch/powerpc 2015-10-21 18:05:50 -05:00
fsl_pamu.h iommu/fsl: Various cleanups 2015-02-03 18:47:18 +01:00
intel_irq_remapping.c SVM fixes for Linux 4.5 2016-02-16 08:04:06 -08:00
intel-iommu.c Merge git://git.infradead.org/intel-iommu 2016-05-27 13:49:24 -07:00
intel-svm.c iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts 2016-02-15 12:42:38 +00:00
io-pgtable-arm-v7s.c iommu/io-pgtable-arm-v7s: Support IOMMU_MMIO flag 2016-04-07 15:07:50 +02:00
io-pgtable-arm.c iommu/io-pgtable-arm: Support IOMMU_MMIO flag 2016-04-07 15:07:50 +02:00
io-pgtable.c iommu/io-pgtable: Fix a brace coding style issue. 2016-04-05 15:34:29 +02:00
io-pgtable.h iommu/io-pgtable: Add MTK 4GB mode in Short-descriptor 2016-04-05 15:39:37 +02:00
iommu-sysfs.c iommu: Fix compile error in iommu-sysfs.c 2014-07-07 12:01:21 +02:00
iommu-traces.c iommu: Add iommu_error class event to iommu trace 2013-09-25 11:07:04 +02:00
iommu.c IOMMU Updates for Linux v4.7 2016-05-19 17:07:04 -07:00
iova.c iommu/iova: introduce per-cpu caching to iova allocation 2016-04-20 15:42:24 -04:00
ipmmu-vmsa.c Merge branches 's390', 'arm/renesas', 'arm/msm', 'arm/shmobile', 'arm/smmu', 'x86/amd' and 'x86/vt-d' into next 2016-01-19 15:30:43 +01:00
irq_remapping.c x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage 2016-04-13 11:37:41 +02:00
irq_remapping.h iommu, x86: Setup Posted-Interrupts capability for Intel iommu 2015-06-12 11:33:52 +02:00
Kconfig Merge branches 'arm/io-pgtable', 'arm/rockchip', 'arm/omap', 'x86/vt-d', 'ppc/pamu', 'core' and 'x86/amd' into next 2016-05-09 19:39:17 +02:00
Makefile iommu/mediatek: Add mt8173 IOMMU driver 2016-02-25 16:49:08 +01:00
msm_iommu_dev.c iommu/msm: Use platform_register/unregister_drivers() 2015-12-14 15:51:21 +01:00
msm_iommu_hw-8xxx.h iommu/msm: Move mach includes to iommu directory 2013-08-06 11:18:03 -07:00
msm_iommu.c iommu/msm: Use BUG_ON instead of if () BUG() 2015-08-13 19:50:51 +02:00
msm_iommu.h iommu/msm: Move mach includes to iommu directory 2013-08-06 11:18:03 -07:00
mtk_iommu.c Merge branches 'arm/io-pgtable', 'arm/rockchip', 'arm/omap', 'x86/vt-d', 'ppc/pamu', 'core' and 'x86/amd' into next 2016-05-09 19:39:17 +02:00
of_iommu.c iommu: of: enforce const-ness of struct iommu_ops 2016-05-09 15:33:29 +02:00
omap-iommu-debug.c iommu/omap: Align code with open parenthesis 2016-04-05 17:53:20 +02:00
omap-iommu.c iommu/omap: Use WARN_ON for page table alignment check 2016-04-05 17:53:20 +02:00
omap-iommu.h iommu/omap: Add support for configuring dsp iommus on DRA7xx 2015-10-14 14:35:47 +02:00
omap-iopgtable.h iommu/omap: Use BIT(x) macros in omap-iopgtable.h 2015-08-03 16:04:42 +02:00
rockchip-iommu.c Merge branches 'arm/io-pgtable', 'arm/rockchip', 'arm/omap', 'x86/vt-d', 'ppc/pamu', 'core' and 'x86/amd' into next 2016-05-09 19:39:17 +02:00
s390-iommu.c iommu/s390: Fix sparse warnings 2015-11-26 14:41:01 +01:00
tegra-gart.c Merge branches 'iommu/fixes', 'x86/vt-d', 'x86/amd', 'arm/smmu', 'arm/tegra' and 'core' into next 2015-04-02 13:33:19 +02:00
tegra-smmu.c iommu/tegra-smmu: Parameterize number of TLB lines 2015-08-13 17:05:28 +02:00