From: Andi Shyti <andi.shyti@linux.intel.com>
To: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: thomas.hellstrom@linux.intel.com,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
jani.nikula@intel.com, intel-gfx@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk,
airlied@linux.ie, matthew.auld@intel.com,
Thomas Zimmermann <tzimmermann@suse.de>,
mchehab@kernel.org, nirmoy.das@intel.com
Subject: Re: [Intel-gfx] [PATCH v5 1/7] drm: Move and add a few utility macros into drm util header
Date: Wed, 27 Jul 2022 12:26:19 +0200 [thread overview]
Message-ID: <YuESy0q5X9pksg9M@alfio.lan> (raw)
In-Reply-To: <20220725092528.1281487-2-gwan-gyeong.mun@intel.com>
Hi,
On Mon, Jul 25, 2022 at 12:25:22PM +0300, Gwan-gyeong Mun wrote:
> It moves overflows_type utility macro into drm util header from i915_utils
> header. The overflows_type can be used to catch the truncation between data
> types. And it adds safe_conversion() macro which performs a type conversion
> (cast) of an source value into a new variable, checking that the
> destination is large enough to hold the source value.
> And it adds exact_type and exactly_pgoff_t macro to catch type mis-match
> while compiling.
>
> v3: Add is_type_unsigned() macro (Mauro)
> Modify overflows_type() macro to consider signed data types (Mauro)
> Fix the problem that safe_conversion() macro always returns true
> v4: Fix kernel-doc markups
>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
> ---
> drivers/gpu/drm/i915/i915_utils.h | 5 +-
> include/drm/drm_util.h | 77 +++++++++++++++++++++++++++++++
> 2 files changed, 78 insertions(+), 4 deletions(-)
Jani and Mauro suggested to have this macro in
include/drm/drm_util.h.
Can I please have an ack from one of the drm maintainers so that
I can go ahead an apply this series?
Thanks,
Andi
>
> diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
> index c10d68cdc3ca..345e5b2dc1cd 100644
> --- a/drivers/gpu/drm/i915/i915_utils.h
> +++ b/drivers/gpu/drm/i915/i915_utils.h
> @@ -32,6 +32,7 @@
> #include <linux/types.h>
> #include <linux/workqueue.h>
> #include <linux/sched/clock.h>
> +#include <drm/drm_util.h>
>
> #ifdef CONFIG_X86
> #include <asm/hypervisor.h>
> @@ -111,10 +112,6 @@ bool i915_error_injected(void);
> #define range_overflows_end_t(type, start, size, max) \
> range_overflows_end((type)(start), (type)(size), (type)(max))
>
> -/* Note we don't consider signbits :| */
> -#define overflows_type(x, T) \
> - (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
> -
> #define ptr_mask_bits(ptr, n) ({ \
> unsigned long __v = (unsigned long)(ptr); \
> (typeof(ptr))(__v & -BIT(n)); \
> diff --git a/include/drm/drm_util.h b/include/drm/drm_util.h
> index 79952d8c4bba..1de9ee5704fa 100644
> --- a/include/drm/drm_util.h
> +++ b/include/drm/drm_util.h
> @@ -62,6 +62,83 @@
> */
> #define for_each_if(condition) if (!(condition)) {} else
>
> +/**
> + * is_type_unsigned - helper for checking data type which is an unsigned data
> + * type or not
> + * @x: The data type to check
> + *
> + * Returns:
> + * True if the data type is an unsigned data type, false otherwise.
> + */
> +#define is_type_unsigned(x) ((typeof(x))-1 >= (typeof(x))0)
> +
> +/**
> + * overflows_type - helper for checking the truncation between data types
> + * @x: Source for overflow type comparison
> + * @T: Destination for overflow type comparison
> + *
> + * It compares the values and size of each data type between the first and
> + * second argument to check whether truncation can occur when assigning the
> + * first argument to the variable of the second argument.
> + * Source and Destination can be used with or without sign bit.
> + * Composite data structures such as union and structure are not considered.
> + * Enum data types are not considered.
> + * Floating point data types are not considered.
> + *
> + * Returns:
> + * True if truncation can occur, false otherwise.
> + */
> +
> +#define overflows_type(x, T) \
> + (is_type_unsigned(x) ? \
> + is_type_unsigned(T) ? \
> + (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) ? 1 : 0 \
> + : (sizeof(x) >= sizeof(T) && (x) >> (BITS_PER_TYPE(T) - 1)) ? 1 : 0 \
> + : is_type_unsigned(T) ? \
> + ((x) < 0) ? 1 : (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) ? 1 : 0 \
> + : (sizeof(x) > sizeof(T)) ? \
> + ((x) < 0) ? (((x) * -1) >> BITS_PER_TYPE(T)) ? 1 : 0 \
> + : ((x) >> BITS_PER_TYPE(T)) ? 1 : 0 \
> + : 0)
> +
> +/**
> + * exact_type - break compile if source type and destination value's type are
> + * not the same
> + * @T: Source type
> + * @n: Destination value
> + *
> + * It is a helper macro for a poor man's -Wconversion: only allow variables of
> + * an exact type. It determines whether the source type and destination value's
> + * type are the same while compiling, and it breaks compile if two types are
> + * not the same
> + */
> +#define exact_type(T, n) \
> + BUILD_BUG_ON(!__builtin_constant_p(n) && !__builtin_types_compatible_p(T, typeof(n)))
> +
> +/**
> + * exactly_pgoff_t - helper to check if the type of a value is pgoff_t
> + * @n: value to compare pgoff_t type
> + *
> + * It breaks compile if the argument value's type is not pgoff_t type.
> + */
> +#define exactly_pgoff_t(n) exact_type(pgoff_t, n)
> +
> +/**
> + * safe_conversion - perform a type conversion (cast) of an source value into
> + * a new variable, checking that the destination is large enough to hold the
> + * source value.
> + * @ptr: Destination pointer address
> + * @value: Source value
> + *
> + * Returns:
> + * If the value would overflow the destination, it returns false.
> + */
> +#define safe_conversion(ptr, value) ({ \
> + typeof(value) __v = (value); \
> + typeof(ptr) __ptr = (ptr); \
> + overflows_type(__v, *__ptr) ? 0 : ((*__ptr = (typeof(*__ptr))__v), 1); \
> +})
> +
> /**
> * drm_can_sleep - returns true if currently okay to sleep
> *
> --
> 2.34.1
next prev parent reply other threads:[~2022-07-27 10:28 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-25 9:25 [PATCH v5 0/7] Fixes integer overflow or integer truncation issues in page lookups, ttm place configuration and scatterlist creation Gwan-gyeong Mun
2022-07-25 9:25 ` [PATCH v5 1/7] drm: Move and add a few utility macros into drm util header Gwan-gyeong Mun
2022-07-25 11:36 ` [Intel-gfx] " Andrzej Hajda
2022-07-26 8:20 ` Gwan-gyeong Mun
2022-07-27 10:26 ` Andi Shyti [this message]
2022-08-03 14:05 ` Jani Nikula
2022-08-04 9:06 ` Andi Shyti
2022-08-09 8:31 ` Gwan-gyeong Mun
2022-07-25 9:25 ` [PATCH v5 2/7] drm/i915/gem: Typecheck page lookups Gwan-gyeong Mun
2022-07-25 11:50 ` [Intel-gfx] " Andrzej Hajda
2022-07-25 9:25 ` [PATCH v5 3/7] drm/i915: Check for integer truncation on scatterlist creation Gwan-gyeong Mun
2022-07-25 11:51 ` [Intel-gfx] " Andrzej Hajda
2022-07-25 9:25 ` [PATCH v5 4/7] drm/i915: Check for integer truncation on the configuration of ttm place Gwan-gyeong Mun
2022-07-25 11:53 ` [Intel-gfx] " Andrzej Hajda
2022-08-03 14:13 ` Jani Nikula
2022-07-25 9:25 ` [PATCH v5 5/7] drm/i915: Check if the size is too big while creating shmem file Gwan-gyeong Mun
2022-07-25 11:59 ` [Intel-gfx] " Andrzej Hajda
2022-07-25 9:25 ` [PATCH v5 6/7] drm/i915: Use error code as -E2BIG when the size of gem ttm object is too large Gwan-gyeong Mun
2022-07-25 12:01 ` [Intel-gfx] " Andrzej Hajda
2022-07-25 9:25 ` [PATCH v5 7/7] drm/i915: Remove truncation warning for large objects Gwan-gyeong Mun
2022-07-25 12:02 ` [Intel-gfx] " Andrzej Hajda
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YuESy0q5X9pksg9M@alfio.lan \
--to=andi.shyti@linux.intel.com \
--cc=airlied@linux.ie \
--cc=chris@chris-wilson.co.uk \
--cc=dri-devel@lists.freedesktop.org \
--cc=gwan-gyeong.mun@intel.com \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@intel.com \
--cc=matthew.auld@intel.com \
--cc=mchehab@kernel.org \
--cc=nirmoy.das@intel.com \
--cc=thomas.hellstrom@linux.intel.com \
--cc=tvrtko.ursulin@linux.intel.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).