LinuxKPI: Fix simple_read_from_buffer for zero-size and off-the-end reads

I noticed that the buf_size < 0 check can never be true (it's a
size_t) and decided to check for this condition by an altern

LinuxKPI: Fix simple_read_from_buffer for zero-size and off-the-end reads

I noticed that the buf_size < 0 check can never be true (it's a
size_t) and decided to check for this condition by an alternate
expression, and I also noticed that a read_size of 0 would incorrectly
return -EFAULT. Instead, return success for both of these cases as
reading beyond the EOF of a normal file also returns EOF, not EINVAL.

Reviewed by: bz
Sponsored by: AFRL, DARPA
Differential Revision: https://reviews.freebsd.org/D55845

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lindebugfs: Pass user buffer pointers to the read/write file operations

The Linux file_operations API expects the read and write operations
to take a single user buffer pointer (along with the lengt

lindebugfs: Pass user buffer pointers to the read/write file operations

The Linux file_operations API expects the read and write operations
to take a single user buffer pointer (along with the length and the
file offset as an in/out parameter).

However, the debugfs_fill function was violating this part of the
contract as it was passing down kernel pointers instead. An earlier
commit (5668c22a13c6befa9b8486387d38457c40ce7af4) hacked around this
by modifying simple_read_from_buffer() to treat its user pointer
argument as a kernel pointer instead. However, other commits keep
tripping over this same API mismatch
(e.g. 78e25e65bf381303c8bdac9a713ab7b26a854b8c passes a kernel pointer
to copy_from_user in fops_str_write).

Instead, change debugfs_fill to use the "raw" pseudofs mode where the
uio is passed down to directly to the fill callback rather than an
sbuf. debufs_fill now iterates over the iovec in the uio similar to
the implementation of uiomove invoking the read or write operation on
each user pointer.

This also fixes a tiny bug where the initial file offset from
uio_offset was ignored. Instead, the operations were always invoked
with a file offset of 0.

As part of this, revert the the changes to simple_read_from_buffer()
from commit 5668c22a13c6befa9b8486387d38457c40ce7af4.

Also as part of this, the simple_attr_read/write methods and seq_read
now also need to accept and handle user pointers (also matching the
API in Linux).

For simple_attr_write*(), copy the user buffer into a kernel buffer
before parsing. Also, do not permit writes at an offset as it's
unclear what the semantics for those would even be (perhaps you would
write out the formatted value into a buffer first and then allow the
copy_from_user to overwrite/extend that buffer and then re-parse the
integer value?). The old handling of *ppos for writes was definitely
wrong before and only worked for an offset of 0 anyway.

Reviewed by: bz
Sponsored by: AFRL, DARPA
Differential Revision: https://reviews.freebsd.org/D55833

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linuxkpi: Add `show_fdinfo()` to `struct file_operations`

We never call this field but it allows to compile drivers without
modifications.

This is used by the DRM drivers for some time, but another

linuxkpi: Add `show_fdinfo()` to `struct file_operations`

We never call this field but it allows to compile drivers without
modifications.

This is used by the DRM drivers for some time, but another change part
of the update to Linux 6.8 led to compile them with `CONFIG_PROC_FS`.
This connected code that uses this struct field.

Reviewed by: bz
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D49069

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linuxkpi: Defaults to `get_file_rcu()` version from Linux 6.7

To use the old version, one has to explicitly set `LINUXKPI_VERSION` to
the expected version of Linux KPI.

Reported by: bz
Reviewed by:

linuxkpi: Defaults to `get_file_rcu()` version from Linux 6.7

To use the old version, one has to explicitly set `LINUXKPI_VERSION` to
the expected version of Linux KPI.

Reported by: bz
Reviewed by: bz
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48860

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linuxkpi: Add `get_file_active()`

[Why]
This is used by the i915 DRM driver starting from Linux 6.7.

Reviewed by: manu
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.fr

linuxkpi: Add `get_file_active()`

[Why]
This is used by the i915 DRM driver starting from Linux 6.7.

Reviewed by: manu
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48757

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linuxkpi: Add Linux 6.7 `get_file_rcu()` variant

[Why]
In Linux 6.7, the signature of `get_file_rcu()` changed significantly,
going from:

bool get_file_rcu(struct linux_file *f);

... to:

linuxkpi: Add Linux 6.7 `get_file_rcu()` variant

[Why]
In Linux 6.7, the signature of `get_file_rcu()` changed significantly,
going from:

bool get_file_rcu(struct linux_file *f);

... to:

struct linux_file * get_file_rcu(struct linux_file **f);

I.e., both the argument and the return value changed in an incompatible
way.

This is used by the i915 DRM driver.

[How]
This patch introduces the variant and hide the new prototype behind
`LINUXKPI_VERSION >= 60700`.

Reviewed by: manu
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48756

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LinuxKPI/lindebugfs: stop panicing in lindebugfs, fix simple_read_from_buffer

Trying to use lindebugfs for debugging wirless drivers two issues
became apparent:
(a) a panic in lindebugfs calling a h

LinuxKPI/lindebugfs: stop panicing in lindebugfs, fix simple_read_from_buffer

Trying to use lindebugfs for debugging wirless drivers two issues
became apparent:
(a) a panic in lindebugfs calling a hard coded release function if the
caller had not provided one. This seems to be based on assumptions
that no longer hold up. Remove the hard coded release function to
prevent panics.
(b) In LinuxKPI simple_read_from_buffer() would call copy_to_user() but
buffers weren't setup for this (lindebugfs copies data from its
own buffer) and then pseudofs will do another copyout to the user
on this; remove the copy_to_user() and simply copy the data over
to the provided buffer; this works for as long as the only consumers
remain debugfs callers (which currently seems to be the case).
[the only out-of-tree consumers I am aware off are two drm-kmod
drivers/gpu/drm/amd/pm/* debugfs functions I cannot test].

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Tested by: jfree
Differential Revision: https://reviews.freebsd.org/D45755

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LinuxKPI: Add DEFINE_DEBUGFS_ATTRIBUTE_SIGNED to linux/debugfs.h

Sponsored by: Serenity CyberSecurity, LLC
MFC after: 1 week
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D456

LinuxKPI: Add DEFINE_DEBUGFS_ATTRIBUTE_SIGNED to linux/debugfs.h

Sponsored by: Serenity CyberSecurity, LLC
MFC after: 1 week
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D45615

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sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remov

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

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sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

LinuxKPI: add a no-op generic_file_llseek()

This is needed for debugfs implementations in drivers.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
OKed by: jfree
Differential Revision: https

LinuxKPI: add a no-op generic_file_llseek()

This is needed for debugfs implementations in drivers.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
OKed by: jfree
Differential Revision: https://reviews.freebsd.org/D37092

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linuxkpi: drm-kmod debugfs support

This diff extends LinuxKPI to support simple attribute files in debugfs.
These simple attributes are an essential component for compiling drm-kmod
with CONFIG_DEBU

linuxkpi: drm-kmod debugfs support

This diff extends LinuxKPI to support simple attribute files in debugfs.
These simple attributes are an essential component for compiling drm-kmod
with CONFIG_DEBUG_FS enabled.
This will allow for easier graphics driver debugging using
Intel's igt-gpu-tools.

Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D35883
Sponsored by: Google, Inc. (GSoC 2022)

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LinuxKPI: Constantly use _LINUXKPI_ prefix in include guards

MFC after: 1 week
Reviewed by: bz, emaste, hselasky, manu
Differential Revision: https://reviews.freebsd.org/D33562

LinuxKPI: Add some typical header pollution

To reduce amount of drm-kmod patching

MFC after: 1 week
Reviewed by: hselasky, manu
Differential Revision: https://reviews.freebsd.org/D33297

LinuxKPI: add simple_open() to fs.h

Add a dummy simple_open() to fs.h as we have for other
(unsupported) functions.
This is needed by a wireless driver.

MFC after: 3 days
Reviewed by: hselasky
Diff

LinuxKPI: add simple_open() to fs.h

Add a dummy simple_open() to fs.h as we have for other
(unsupported) functions.
This is needed by a wireless driver.

MFC after: 3 days
Reviewed by: hselasky
Differential Revision: https://reviews.freebsd.org/D32642

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LinuxKPI: Implement get_file_rcu()

get_file_rcu() grabs a file if the file->f_count is not zero.

Required by drm-kmod 5.6

Reviewed by: hselasky, manu (previous version)
MFC after: 2 weeks
Differen

LinuxKPI: Implement get_file_rcu()

get_file_rcu() grabs a file if the file->f_count is not zero.

Required by drm-kmod 5.6

Reviewed by: hselasky, manu (previous version)
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D31672

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linuxkpi: Add dmi_* function

dmi function are used to get smbios values.
The DRM subsystem and drivers use it to enabled (or not) quirks.

Reviewed by: hselasky
Sponsored by: The FreeBSD Foundation

linuxkpi: Add dmi_* function

dmi function are used to get smbios values.
The DRM subsystem and drivers use it to enabled (or not) quirks.

Reviewed by: hselasky
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26046

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compat: clean up empty lines in .c and .h files

MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

Merge ^/head r364264 through r364278.

vfs: remove the thread argument from vget

It was already asserted to be curthread.

Semantic patch:

@@

expression arg1, arg2, arg3;

@@

- vget(arg1, arg2, arg3)
+ vget(arg1, arg2)

Merge r358179 through r358238.

PR: 244251

linuxkpi: Move shmem related functions in it's own file

For drmkpi (D23085) we don't want the Linux struct file as we don't emulate
everything. Also the prototypes should be in shmem_fs.h to have 10

linuxkpi: Move shmem related functions in it's own file

For drmkpi (D23085) we don't want the Linux struct file as we don't emulate
everything. Also the prototypes should be in shmem_fs.h to have 100%
compatibility with Linux.

Reviewed by: hselasky
MFC after: Maybe
Differential Revision: https://reviews.freebsd.org/D23764

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MFhead@r344527

Merge ^/head r344178 through r344512.