iommufd is the user API to control the IOMMU subsystem as it relates to
managing IO page tables that point at user space memory.
It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO
container) which is the VFIO specific interface for a similar idea.
We see a broad need for extended features, some being highly IOMMU device
specific:
- Binding iommu_domain's to PASID/SSID
- Userspace IO page tables, for ARM, x86 and S390
- Kernel bypassed invalidation of user page tables
- Re-use of the KVM page table in the IOMMU
- Dirty page tracking in the IOMMU
- Runtime Increase/Decrease of IOPTE size
- PRI support with faults resolved in userspace
Many of these HW features exist to support VM use cases - for instance the
combination of PASID, PRI and Userspace IO Page Tables allows an
implementation of DMA Shared Virtual Addressing (vSVA) within a
guest. Dirty tracking enables VM live migration with SRIOV devices and
PASID support allow creating "scalable IOV" devices, among other things.
As these features are fundamental to a VM platform they need to be
uniformly exposed to all the driver families that do DMA into VMs, which
is currently VFIO and VDPA.
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd
Pull iommufd implementation from Jason Gunthorpe:
"iommufd is the user API to control the IOMMU subsystem as it relates
to managing IO page tables that point at user space memory.
It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO
container) which is the VFIO specific interface for a similar idea.
We see a broad need for extended features, some being highly IOMMU
device specific:
- Binding iommu_domain's to PASID/SSID
- Userspace IO page tables, for ARM, x86 and S390
- Kernel bypassed invalidation of user page tables
- Re-use of the KVM page table in the IOMMU
- Dirty page tracking in the IOMMU
- Runtime Increase/Decrease of IOPTE size
- PRI support with faults resolved in userspace
Many of these HW features exist to support VM use cases - for instance
the combination of PASID, PRI and Userspace IO Page Tables allows an
implementation of DMA Shared Virtual Addressing (vSVA) within a guest.
Dirty tracking enables VM live migration with SRIOV devices and PASID
support allow creating "scalable IOV" devices, among other things.
As these features are fundamental to a VM platform they need to be
uniformly exposed to all the driver families that do DMA into VMs,
which is currently VFIO and VDPA"
For more background, see the extended explanations in Jason's pull request:
https://lore.kernel.org/lkml/Y5dzTU8dlmXTbzoJ@nvidia.com/
* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (62 commits)
iommufd: Change the order of MSI setup
iommufd: Improve a few unclear bits of code
iommufd: Fix comment typos
vfio: Move vfio group specific code into group.c
vfio: Refactor dma APIs for emulated devices
vfio: Wrap vfio group module init/clean code into helpers
vfio: Refactor vfio_device open and close
vfio: Make vfio_device_open() truly device specific
vfio: Swap order of vfio_device_container_register() and open_device()
vfio: Set device->group in helper function
vfio: Create wrappers for group register/unregister
vfio: Move the sanity check of the group to vfio_create_group()
vfio: Simplify vfio_create_group()
iommufd: Allow iommufd to supply /dev/vfio/vfio
vfio: Make vfio_container optionally compiled
vfio: Move container related MODULE_ALIAS statements into container.c
vfio-iommufd: Support iommufd for emulated VFIO devices
vfio-iommufd: Support iommufd for physical VFIO devices
vfio-iommufd: Allow iommufd to be used in place of a container fd
vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()
...
Make a few changes to cause functions documented by kerneldoc to stand out
better in the rendered documentation. Specifically, change kernel-doc to
put the description section into a ".. container::" section, then add a bit
of CSS to indent that section relative to the function prototype (or struct
or enum definition). Tweak a few other CSS parameters while in the
neighborhood to improve the formatting.
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Some warnings do not increment the warnings counter making the behavior
of running kernel-doc with -Werror unlogical as some warnings will be
generated but not treated as errors.
Fix this by creating a helper function that always incrementing the
warnings counter every time a warning is emitted. There is one location
in get_sphinx_version() where a warning is not touched as it concerns
the execution environment of the kernel-doc and not the documentation
being processed.
Incrementing the counter only have effect when running kernel-doc in
either verbose mode (-v or environment variable KBUILD_VERBOSE) or when
treating warnings as errors (-Werror or environment variable
KDOC_WERROR). In both cases the number of warnings printed is printed to
stderr and for the later the exit code of kernel-doc is non-zero if
warnings where encountered.
Simple test case to demo one of the warnings,
$ cat test.c
/**
* foo() - Description
*/
int bar();
# Without this change
$ ./scripts/kernel-doc -Werror -none test.c
test.c:4: warning: expecting prototype for foo(). Prototype was for
bar() instead
# With this change
$ ./scripts/kernel-doc -Werror -none test.c
test.c:4: warning: expecting prototype for foo(). Prototype was for
bar() instead
1 warnings as Errors
Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Link: https://lore.kernel.org/r/20220613090510.3088294-1-niklas.soderlund@corigine.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, when there is no FILE argument following a switch such
as -man, -rst, or -none, kernel-doc exits with a warning from perl
(long msg folded):
Use of uninitialized value $ARGV[0] in pattern match (m//)
at ./scripts/kernel-doc line 438.
, which is unhelpful.
Improve the behavior by adding a check at the bottom of parsing
loop.
If the argument is absent, display help text and exit with
the code of 1 (via usage()).
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/7b136049-a3ba-0eb5-8717-364d773ff914@gmail.com
[jc: reworked to fix conflict with pod patches]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
I wanted to clean up these lines, but in the end decided not to touch
the old ones and just add my own about POD. I'll leave the cleanup
for lawyers.
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-12-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
What for? To improve the script maintainability.
1. License
As stated by Jonathan Corbet in the reply to my version 1, the SPDX line
is enough.
2. The to-do list comment
As suggested by Jonathan Corbet in reply to my version 3, this section
doesn't need to be transitioned. And so it is removed for clarity.
3. The historical changelog comments
As suggested by Jonathan Corbet in a reply to v3, this section can go.
I wanted to keep it, but since it doesn't contain copyright notices,
let's just have it clean and simple.
4. The "format of comments" comment block
As suggested by Jani Nikula in a reply to my first version of this
transformation, Documentation/doc-guide/kernel-doc.rst can serve as the
information hub for comment formatting. The section DESCRIPTION already
points there, so the original comment block can just be removed.
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-11-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Aim: unified POD, user more satisfied, script better structured
You can see the results with:
$ scripts/kernel-doc -help
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-10-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Aim: unified POD, user more satisfied, script better structured
Notes:
- The -help token is added.
- The entries are sorted alphbetically.
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-9-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Aim: unified POD, user more satisfied, script better structured
A subsection "reStructuredText only" is added for -enable-lineno.
Other notes:
- paragraphing correction
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-8-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Aim: unified POD, user more satisfied, script better structured
The plurals in -function and -nosymbol are corrected to singulars.
That's how the script works now. I think this describes the syntax better.
The plurar suggests multiple FILE arguments might be possible. So this
seems more coherent.
Other notes:
- paragraphing correction
- article correction
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-7-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Aim: unified POD, user more happy
This section is renamed to "Output format modifiers" to make it simple.
To make it even more simple, a subsection is added:
"reStructuredText only".
Other notes:
- paragraphing correction
- article correction
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-6-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Another step in the direction of a uniform POD documentation, which will
make users happier.
Options land at the end of the script, not to clutter the file top.
The default output format is corrected to rst. That's what it is now.
A POD delimiting comment is added to the script head, which improves
the script logical structure.
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-5-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Transition the description section into POD. This is one of the standard
documentation sections. This adjustment makes the section available for
POD and makes it look better.
Notes:
- an article addition
- paragraphing correction
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-4-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The former usage function is substituted, although not as the -h and -help
parameter handler yet.
Purpose: Use Pod::Usage to handle documentation printing in an integrated
way.
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-3-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The NAME section provides the doc title, while SYNOPSIS contains
the basic syntax and usage description, which will be printed
in the help document and in the error output produced on wrong script
usage.
The rationale is to give users simple and succinct enlightment,
at the same time structuring the script internally for the maintainers.
In the synopsis, Rst-only options are grouped around rst, and the rest is
arranged as in the OPTIONS subsections (yet to be translated into POD,
check at the end of the series).
The third of the basic sections, DESCRIPTION, is added separately.
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-2-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
- Some small scripts/kerneldoc fixes
- More Chinese translation work, but at a much reduced rate.
- The tip-tree maintainer's handbook
...plus the usual array of build fixes, typo fixes, etc.
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Merge tag 'docs-5.16' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"This is a relatively unexciting cycle for documentation.
- Some small scripts/kerneldoc fixes
- More Chinese translation work, but at a much reduced rate.
- The tip-tree maintainer's handbook
...plus the usual array of build fixes, typo fixes, etc"
* tag 'docs-5.16' of git://git.lwn.net/linux: (53 commits)
kernel-doc: support DECLARE_PHY_INTERFACE_MASK()
docs/zh_CN: add core-api xarray translation
docs/zh_CN: add core-api assoc_array translation
speakup: Fix typo in documentation "boo" -> "boot"
docs: submitting-patches: make section about the Link: tag more explicit
docs: deprecated.rst: Clarify open-coded arithmetic with literals
scripts: documentation-file-ref-check: fix bpf selftests path
scripts: documentation-file-ref-check: ignore hidden files
coding-style.rst: trivial: fix location of driver model macros
docs: f2fs: fix text alignment
docs/zh_CN add PCI pci.rst translation
docs/zh_CN add PCI index.rst translation
docs: translations: zh_CN: memory-hotplug.rst: fix a typo
docs: translations: zn_CN: irq-affinity.rst: add a missing extension
block: add documentation for inflight
scripts: kernel-doc: Ignore __alloc_size() attribute
docs: pdfdocs: Adjust \headheight for fancyhdr
docs: UML: user_mode_linux_howto_v2 edits
docs: use the lore redirector everywhere
docs: proc.rst: mountinfo: align columns
...
Support the DECLARE_PHY_INTERFACE_MASK() macro that is used to declare
a bitmap by converting the macro to DECLARE_BITMAP(), as has been done
for the __ETHTOOL_DECLARE_LINK_MODE_MASK() macro.
This fixes a 'make htmldocs' warning:
include/linux/phylink.h:82: warning: Function parameter or member 'DECLARE_PHY_INTERFACE_MASK(supported_interfaces' not described in 'phylink_config'
that was introduced by commit
38c310eb46 ("net: phylink: add MAC phy_interface_t bitmap")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/45934225-7942-4326-f883-a15378939db9@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There are many places where kernel code wants to have several different
typed trailing flexible arrays. This would normally be done with multiple
flexible arrays in a union, but since GCC and Clang don't (on the surface)
allow this, there have been many open-coded workarounds, usually involving
neighboring 0-element arrays at the end of a structure. For example,
instead of something like this:
struct thing {
...
union {
struct type1 foo[];
struct type2 bar[];
};
};
code works around the compiler with:
struct thing {
...
struct type1 foo[0];
struct type2 bar[];
};
Another case is when a flexible array is wanted as the single member
within a struct (which itself is usually in a union). For example, this
would be worked around as:
union many {
...
struct {
struct type3 baz[0];
};
};
These kinds of work-arounds cause problems with size checks against such
zero-element arrays (for example when building with -Warray-bounds and
-Wzero-length-bounds, and with the coming FORTIFY_SOURCE improvements),
so they must all be converted to "real" flexible arrays, avoiding warnings
like this:
fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
209 | anode->btree.u.internal[0].down = cpu_to_le32(a);
| ~~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from fs/hpfs/hpfs_fn.h:26,
from fs/hpfs/anode.c:10:
fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
412 | struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
| ^~~~~~~~
drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
360 | tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
231 | u8 raw_msg[0];
| ^~~~~~~
However, it _is_ entirely possible to have one or more flexible arrays
in a struct or union: it just has to be in another struct. And since it
cannot be alone in a struct, such a struct must have at least 1 other
named member -- but that member can be zero sized. Wrap all this nonsense
into the new DECLARE_FLEX_ARRAY() in support of having flexible arrays
in unions (or alone in a struct).
As with struct_group(), since this is needed in UAPI headers as well,
implement the core there, with a non-UAPI wrapper.
Additionally update kernel-doc to understand its existence.
https://github.com/KSPP/linux/issues/137
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Fixes "Compiler Attributes: add __alloc_size() for better bounds checking"
so that the __alloc_size() macro is ignored for function prototypes when
generating kerndoc. Avoids warnings like:
./include/linux/slab.h:662: warning: Function parameter or member '1' not described in '__alloc_size'
./include/linux/slab.h:662: warning: Function parameter or member '2' not described in '__alloc_size'
./include/linux/slab.h:662: warning: expecting prototype for kcalloc(). Prototype was for __alloc_size() instead
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211011180650.3603988-1-keescook@chromium.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Kernel code has a regular need to describe groups of members within a
structure usually when they need to be copied or initialized separately
from the rest of the surrounding structure. The generally accepted design
pattern in C is to use a named sub-struct:
struct foo {
int one;
struct {
int two;
int three, four;
} thing;
int five;
};
This would allow for traditional references and sizing:
memcpy(&dst.thing, &src.thing, sizeof(dst.thing));
However, doing this would mean that referencing struct members enclosed
by such named structs would always require including the sub-struct name
in identifiers:
do_something(dst.thing.three);
This has tended to be quite inflexible, especially when such groupings
need to be added to established code which causes huge naming churn.
Three workarounds exist in the kernel for this problem, and each have
other negative properties.
To avoid the naming churn, there is a design pattern of adding macro
aliases for the named struct:
#define f_three thing.three
This ends up polluting the global namespace, and makes it difficult to
search for identifiers.
Another common work-around in kernel code avoids the pollution by avoiding
the named struct entirely, instead identifying the group's boundaries using
either a pair of empty anonymous structs of a pair of zero-element arrays:
struct foo {
int one;
struct { } start;
int two;
int three, four;
struct { } finish;
int five;
};
struct foo {
int one;
int start[0];
int two;
int three, four;
int finish[0];
int five;
};
This allows code to avoid needing to use a sub-struct named for member
references within the surrounding structure, but loses the benefits of
being able to actually use such a struct, making it rather fragile. Using
these requires open-coded calculation of sizes and offsets. The efforts
made to avoid common mistakes include lots of comments, or adding various
BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason
about the boundaries (e.g. the "start" object looks like it's 0 bytes
in length), making bounds checking depend on open-coded calculations:
if (length > offsetof(struct foo, finish) -
offsetof(struct foo, start))
return -EINVAL;
memcpy(&dst.start, &src.start, offsetof(struct foo, finish) -
offsetof(struct foo, start));
However, the vast majority of places in the kernel that operate on
groups of members do so without any identification of the grouping,
relying either on comments or implicit knowledge of the struct contents,
which is even harder for the compiler to reason about, and results in
even more fragile manual sizing, usually depending on member locations
outside of the region (e.g. to copy "two" and "three", use the start of
"four" to find the size):
BUILD_BUG_ON((offsetof(struct foo, four) <
offsetof(struct foo, two)) ||
(offsetof(struct foo, four) <
offsetof(struct foo, three));
if (length > offsetof(struct foo, four) -
offsetof(struct foo, two))
return -EINVAL;
memcpy(&dst.two, &src.two, length);
In order to have a regular programmatic way to describe a struct
region that can be used for references and sizing, can be examined for
bounds checking, avoids forcing the use of intermediate identifiers,
and avoids polluting the global namespace, introduce the struct_group()
macro. This macro wraps the member declarations to create an anonymous
union of an anonymous struct (no intermediate name) and a named struct
(for references and sizing):
struct foo {
int one;
struct_group(thing,
int two;
int three, four;
);
int five;
};
if (length > sizeof(src.thing))
return -EINVAL;
memcpy(&dst.thing, &src.thing, length);
do_something(dst.three);
There are some rare cases where the resulting struct_group() needs
attributes added, so struct_group_attr() is also introduced to allow
for specifying struct attributes (e.g. __align(x) or __packed).
Additionally, there are places where such declarations would like to
have the struct be tagged, so struct_group_tagged() is added.
Given there is a need for a handful of UAPI uses too, the underlying
__struct_group() macro has been defined in UAPI so it can be used there
too.
To avoid confusing scripts/kernel-doc, hide the macro from its struct
parsing.
Co-developed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor
Enhanced-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk
Enhanced-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com
Enhanced-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Since commit 2c12c8103d ("scripts/kernel-doc: optionally treat
warnings as errors"), the kernel-doc script will treat warnings as
errors when one of the following conditions is true:
- The KDOC_WERROR environment variable is non-zero
- The KCFLAGS environment variable contains -Werror
- The -Werror parameter is passed to kernel-doc
Checking KCFLAGS for -Werror allows piggy-backing on the C compiler
error handling. However, unlike the C compiler, kernel-doc has no
provision for -Wno-error. This makes compiling the kernel with -Werror
(to catch regressions) and W=1 (to enable more checks) always fail,
without the same possibility as offered by the C compiler to treating
some selected warnings as warnings despite the global -Werror setting.
To fix this, evaluate KDOC_WERROR after KCFLAGS, which allows disabling
the warnings-as-errors behaviour of kernel-doc selectively by setting
KDOC_WERROR=0.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20210730225401.4401-1-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There are some regex expressions in the kernel-doc script, which are used
repeatedly in the script.
Reduce such expressions into variables, which can be used everywhere.
A quick manual check found that no errors and warnings were added/removed
in this process.
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210514144244.25341-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The current linux-next tree has a new error:
./Documentation/gpu/drm-mm:445: ./drivers/gpu/drm/drm_prime.c:994: WARNING: Error in declarator or parameters
Invalid C declaration: Expecting "(" in parameters. [error at 17]
int __deprecated drm_prime_sg_to_page_array (struct sg_table *sgt, struct page **pages, int max_entries)
-----------------^
While we might consider that documenting a deprecated interface is not
necessarily best practice, removing the error is easy.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20210427114828.GY235567@casper.infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently kernel-doc does not identify some cases of probable kernel
doc comments, for e.g. pointer used as declaration type for identifier,
space separated identifier, etc.
Some example of these cases in files can be:
i)" * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure"
in fs/jbd2/journal.c
ii) "* dget, dget_dlock - get a reference to a dentry" in
include/linux/dcache.h
iii) " * DEFINE_SEQLOCK(sl) - Define a statically allocated seqlock_t"
in include/linux/seqlock.h
Also improve identification for non-kerneldoc comments. For e.g.,
i) " * The following functions allow us to read data using a swap map"
in kernel/power/swap.c does follow the kernel-doc like syntax, but the
content inside does not adheres to the expected format.
Improve parsing by adding support for these probable attempts to write
kernel-doc comment.
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/lkml/87mtujktl2.fsf@meer.lwn.net
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210414192529.9080-1-yashsri421@gmail.com
[ jc: fixed some line-length issues ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, kernel-doc start parsing the comment as a kernel-doc comment if
it starts with '/**', but does not take into account if the content inside
the comment too, adheres with the expected format.
This results in unexpected and unclear warnings for the user.
E.g., running scripts/kernel-doc -none mm/memcontrol.c emits:
"mm/memcontrol.c:961: warning: expecting prototype for do not fallback to current(). Prototype was for get_mem_cgroup_from_current() instead"
Here kernel-doc parses the corresponding comment as a kernel-doc comment
and expects prototype for it in the next lines, and as a result causing
this warning.
Provide a clearer warning message to the users regarding the same, if the
content inside the comment does not follow the kernel-doc expected format.
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210329092945.13152-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The previous attempt to properly handle literal blocks broke parsing of
parameter lines containing colons; fix it by tweaking the regex to
specifically exclude the "::" pattern while accepting lines containing
colons in general. Add a little documentation to the regex while in the
neighborhood.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 8d295fbad6 ("kernel-doc: better handle '::' sequences")
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Right now, if one of the following headers end with a '::', the
kernel-doc script will do the wrong thing:
description|context|returns?|notes?|examples?
The real issue is with examples, as people could try to write
something like:
example::
/* Some C code */
and this won't be properly evaluated. So, improve the regex
to not catch '\w+::' regex for the above identifiers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/2cf44cf1fa42588632735d4fbc8e84304bdc235f.1616696051.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
When anonymous enums are used, the identifier is empty.
While, IMO, it should be avoided the usage of such enums,
adding support for it is not hard.
So, postpone the check for empty identifiers to happen
only at the dump phase.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/055ad57879f1b9381b90879e00f72fde1c3a5647.1614760910.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, kernel-doc warns for function prototype parsing on the
presence of attributes "__attribute_const__" and "__flatten" in the
definition.
There are 166 occurrences in ~70 files in the kernel tree for
"__attribute_const__" and 5 occurrences in 4 files for "__flatten".
Out of 166, there are 3 occurrences in three different files with
"__attribute_const__" and a preceding kernel-doc; and, 1 occurrence in
./mm/percpu.c for "__flatten" with a preceding kernel-doc. All other
occurrences have no preceding kernel-doc.
Add support for "__attribute_const__" and "__flatten" attributes.
A quick evaluation by running 'kernel-doc -none' on kernel-tree reveals
that no additional warning or error has been added or removed by the fix.
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210306113510.31023-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, there are ~1290 occurrences in 447 files in the kernel tree
'typedef struct/union' syntax for defining some struct/union. However,
kernel-doc currently does not support that syntax. Of the ~1290
occurrences, there are four occurrences in ./include/linux/zstd.h with
typedef struct/union syntax and a preceding kernel-doc; all other
occurrences have no preceding kernel-doc.
Add support for parsing struct/union following this syntax.
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210225145033.11431-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, kernel-doc causes an unexpected error when array element (i.e.,
"type (*foo[bar])(args)") is present as pointer parameter in
pointer-to-function parsing.
For e.g., running kernel-doc -none on kernel/gcov/gcc_4_7.c causes this
error:
"Use of uninitialized value $param in regexp compilation at ...", in
combination with:
"warning: Function parameter or member '' not described in 'gcov_info'"
Here, the parameter parsing does not take into account the presence of
array element (i.e. square brackets) in $param.
Provide a simple fix by adding square brackets in the regex, responsible
for capturing $param.
A quick evaluation, by running 'kernel-doc -none' on entire kernel-tree,
reveals that no additional warning or error has been added or removed by
the fix.
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20210217145625.14006-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
While DOC: section titles are not converted into RST headings
sections and are only decorated with strong emphasis markup,
nothing stops us from generating internal hyperlinks for them,
to mimic implicit hyperlinks to RST headings.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://lore.kernel.org/r/20210118110813.1490-1-michal.wajdeczko@intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Kernel-doc currently expects that the kernel-doc markup to come
just before the function/enum/struct/union/typedef prototype.
Yet, if it find things like:
/**
* refcount_add - add a value to a refcount
* @i: the value to add to the refcount
* @r: the refcount
*/
static inline void __refcount_add(int i, refcount_t *r, int *oldp);
static inline void refcount_add(int i, refcount_t *r);
Kernel-doc will do the wrong thing:
foobar.h:6: warning: Function parameter or member 'oldp' not described in '__refcount_add'
.. c:function:: void __refcount_add (int i, refcount_t *r, int *oldp)
add a value to a refcount
**Parameters**
``int i``
the value to add to the refcount
``refcount_t *r``
the refcount
``int *oldp``
*undescribed*
Basically, it will document "__refcount_add" with the kernel-doc
markup for refcount_add.
If both functions have the same arguments, this won't even
produce any warning!
Add a logic to check if the kernel-doc identifier matches the actual
name of the C function or data structure that will be documented.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/081546f141a496d6cabb99a4adc140444c705e93.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Changeset 6b80975c63 ("scripts: kernel-doc: fix typedef parsing")
added support for things like:
typedef unsigned long foo();
However, it caused a regression on this prototype:
typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);
This is only noticed after adding a patch that checks if the
kernel-doc identifier matches the typedef:
./scripts/kernel-doc -none $(git grep '^.. kernel-doc::' Documentation/ |cut -d ' ' -f 3|sort|uniq) 2>&1|grep expecting
include/media/v4l2-dv-timings.h:38: warning: expecting prototype for typedef v4l2_check_dv_timings_fnc. Prototype was for typedef nc instead
The problem is that, with the new parsing logic, it is not
checking for complete words at the type part.
Fix it by adding a \b at the end of each type word at the
regex.
fixes: 6b80975c63 ("scripts: kernel-doc: fix typedef parsing")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/218ff56dcb8e73755005d3fb64586eb1841a276b.1606896997.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The commit d38c8cfb05 ("scripts: kernel-doc: add support for typedef enum")
broke anonymous enum parsing. Restore it by relying on members rather than
its name.
Fixes: d38c8cfb05 ("scripts: kernel-doc: add support for typedef enum")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20201102170637.36138-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Sphinx C domain code after 3.2.1 will start complaning if :c:struct
would be used for an union type:
.../Documentation/gpu/drm-kms-helpers:352: ../drivers/video/hdmi.c:851: WARNING: C 'identifier' cross-reference uses wrong tag: reference name is 'union hdmi_infoframe' but found name is 'struct hdmi_infoframe'. Full reference name is 'union hdmi_infoframe'. Full found name is 'struct hdmi_infoframe'.
So, let's address this issue too in advance, in order to
avoid future issues.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6e4ec3eec914df62389a299797a3880ae4490f35.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The include/linux/genalloc.h file defined this typedef:
typedef unsigned long (*genpool_algo_t)(unsigned long *map,unsigned long size,unsigned long start,unsigned int nr,void *data, struct gen_pool *pool, unsigned long start_addr);
Because it has a type composite of two words (unsigned long),
the parser gets the typedef name wrong:
.. c:macro:: long
**Typedef**: Allocation callback function type definition
Fix the regex in order to accept composite types when
defining a typedef for a function pointer.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/328e8018041cc44f7a1684e57f8d111230761c4f.1603792384.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There are a few namespace clashes by using c:macro everywhere:
basically, when using it, we can't have something like:
.. c:struct:: pwm_capture
.. c:macro:: pwm_capture
So, we need to use, instead:
.. c:function:: int pwm_capture (struct pwm_device * pwm, struct pwm_capture * result, unsigned long timeout)
for the function declaration.
The kernel-doc change was proposed by Jakob Lykke Andersen here:
6fd2076ec0
Although I did a different implementation.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Address several issues related to pointing to the wrong line
number:
1) ensure that line numbers will always be initialized
When section is the default (Description), the line number
is not initializing, producing this:
$ ./scripts/kernel-doc --enable-lineno ./drivers/media/v4l2-core/v4l2-mem2mem.c|less
**Description**
#define LINENO 0
In case of streamoff or release called on any context,
1] If the context is currently running, then abort job will be called
2] If the context is queued, then the context will be removed from
the job_queue
Which is not right. Ensure that the line number will always
be there. After applied, the result now points to the right location:
**Description**
#define LINENO 410
In case of streamoff or release called on any context,
1] If the context is currently running, then abort job will be called
2] If the context is queued, then the context will be removed from
the job_queue
2) The line numbers for function prototypes are always + 1,
because it is taken at the line after handling the prototype.
Change the logic to point to the next line after the /** */
block;
3) The "DOC:" line number should point to the same line as this
markup is found, and not to the next one.
Probably part of the issues were due to a but that was causing
the line number offset to be incremented by one, if --export
were used.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
When kernel-doc is called via kerneldoc.py, there's no need to
auto-detect the Sphinx version, as the Sphinx module already
knows it. So, add an optional parameter to allow changing the
Sphinx dialect.
As kernel-doc can also be manually called, keep the auto-detection
logic if the parameter was not specified. On such case, emit
a warning if sphinx-build can't be found at PATH.
I ended using a suggestion from Joe for using a more readable
regex, instead of using a complex one with a hidden group like:
m/^(\d+)\.(\d+)(?:\.?(\d+)?)/
in order to get the optional <patch> argument.
Thanks-to: Joe Perches <joe@perches.com>
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
While kernel-doc needs to parse parameters in order to
identify its name, it shouldn't be touching the type,
as parsing it is very difficult, and errors happen.
One current error is when parsing this parameter:
const u32 (*tab)[256]
Found at ./lib/crc32.c, on this function:
u32 __pure crc32_be_generic (u32 crc, unsigned char const *p, size_t len, const u32 (*tab)[256], u32 polynomial);
The current logic mangles it, producing this output:
const u32 ( *tab
That's something that it is not recognizeable.
So, instead, let's push the argument as-is, and use it
when printing the function prototype and when describing
each argument.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Some typedef expressions are output as normal functions.
As we need to be clearer about the type with Sphinx 3.x,
detect such cases.
While here, fix a wrongly-indented block.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Right now, the build system doesn't use -nofunction, as
it is pretty much useless, because it doesn't consider
the other output modes (extern, internal), working only
with all.
Also, it is limited to exclude functions.
Re-implement it in order to allow excluding any symbols from
the document output, no matter what mode is used.
The parameter was also renamed to "-nosymbol", as it express
better its meaning.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
There's currently a bug with the way kernel-doc script
counts line numbers that can be seen with:
$ ./scripts/kernel-doc -rst -enable-lineno include/linux/math64.h >all && ./scripts/kernel-doc -rst -internal -enable-lineno include/linux/math64.h >int && diff -U0 int all
--- int 2020-09-28 12:58:08.927486808 +0200
+++ all 2020-09-28 12:58:08.905486845 +0200
@@ -1 +1 @@
-#define LINENO 27
+#define LINENO 26
@@ -3 +3 @@
-#define LINENO 16
+#define LINENO 15
@@ -9 +9 @@
-#define LINENO 17
+#define LINENO 16
...
This is happening with perl version 5.30.3, but I'm not
so sure if this is a perl bug, or if this is due to something
else.
In any case, fixing it is easy. Basically, when "-internal"
parameter is used, the process_export_file() function opens the
handle "IN". This makes the line number to be incremented, as the
handler for the main open is also "IN".
Fix the problem by using a different handler for the
main open().
While here, add a missing close for it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Unfortunately, Sphinx 3.x parser for c functions is too pedantic:
https://github.com/sphinx-doc/sphinx/issues/8241
While it could be relaxed with some configurations, there are
several corner cases that it would make it hard to maintain,
and will require teaching conf.py about several macros.
So, let's instead use the :c:macro notation. This will
produce an output that it is not as nice as currently, but it
should still be acceptable, and will provide cross-references,
removing thousands of warnings when building with newer
versions of Sphinx.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
With Sphinx 3.x, the ".. c:type:" tag was changed to accept either:
.. c:type:: typedef-like declaration
.. c:type:: name
Using it for other types (including functions) don't work anymore.
So, there are newer tags for macro, enum, struct, union, and others,
which doesn't exist on older versions.
Add a check for the Sphinx version and change the produced tags
accordingly.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The PHY kernel-doc markup has gained support for documenting
a typedef enum.
However, right now the parser was not prepared for it.
So, add support for parsing it.
Fixes: 4069a572d4 ("net: phy: Document core PHY structures")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
