From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Dmitry Kozlyuk" <dmitry.kozliuk@gmail.com>, <dev@dpdk.org>
Cc: <stable@dpdk.org>
Subject: RE: [PATCH 1/3] eal: fix pointer arithmetic with an expression argument
Date: Mon, 22 Aug 2022 09:14:55 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D8728D@smartserver.smartshare.dk> (raw)
In-Reply-To: <20220821205009.1317044-2-dmitry.kozliuk@gmail.com>
> From: Dmitry Kozlyuk [mailto:dmitry.kozliuk@gmail.com]
> Sent: Sunday, 21 August 2022 22.50
>
> RTE_PTR_SUB(ptr, x) and RTE_PTR_ALIGN_FLOOR() worked incorrectly
> if "ptr" was an expression:
>
> uint32_t arr[3];
>
> RTE_PTR_SUB(arr + 1, sizeof(arr[0]));
> // expected: (uint32_t *)((uintptr_t)(arr + 1) - 4) == arr
> // actual: (uint32_t *)((uintptr_t) arr + 1 - 4) != arr
>
> RTE_PTR_ALIGN_FLOOR(arr + 2, sizeof(arr[0]));
> // expected: RTE_ALIGN_FLOOR((uintptr_t)(arr + 2), 4) == &arr[2]
> // actual: RTE_ALIGN_FLOOR((uintptr_t) arr + 2, 4) == &arr[0]
>
> Fix the macros and extend the relevant unit test.
Good catch. Serious bugs!
>
> Fixes: af75078fece3 ("first public release")
> Cc: stable@dpdk.org
>
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
> app/test/test_common.c | 11 +++++++++++
> lib/eal/include/rte_common.h | 4 ++--
> 2 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/app/test/test_common.c b/app/test/test_common.c
> index ef177cecb1..4194c1208a 100644
> --- a/app/test/test_common.c
> +++ b/app/test/test_common.c
> @@ -31,6 +31,7 @@ test_macros(int __rte_unused unused_parm)
>
> uintptr_t unused = 0;
> unsigned int smaller = SMALLER, bigger = BIGGER;
> + uint32_t arr[3];
>
> RTE_SET_USED(unused);
>
> @@ -41,6 +42,16 @@ test_macros(int __rte_unused unused_parm)
> FAIL_MACRO(RTE_PTR_ADD);
> if ((uintptr_t)RTE_PTR_SUB(BIGGER, PTR_DIFF) != SMALLER)
> FAIL_MACRO(RTE_PTR_SUB);
> + if (RTE_PTR_ADD(arr + 1, sizeof(arr[0])) != &arr[2])
> + FAIL_MACRO(RTE_PTR_ADD);
> + if (RTE_PTR_SUB(arr + 1, sizeof(arr[0])) != &arr[0])
> + FAIL_MACRO(RTE_PTR_SUB);
Very elegant test cases. :-)
> + if (RTE_PTR_ALIGN_FLOOR(arr + 2, 4) != &arr[2])
> + FAIL_MACRO(RTE_PTR_ALIGN_FLOOR);
> + if (RTE_PTR_ALIGN_CEIL(arr + 2, 4) != &arr[2])
> + FAIL_MACRO(RTE_PTR_ALIGN_CEIL);
While you are at it, consider adding a few more test cases, e.g.
RTE_PTR_ALIGN_FLOOR/CEIL(RTE_PTR_ADD(&arr[1], 1), 4), and
RTE_PTR_ALIGN_FLOOR/CEIL(RTE_PTR_ADD(&arr[1], sizeof(uint32_t) - 1), 4)
> + if (RTE_PTR_ALIGN(arr + 2, 4) != &arr[2])
> + FAIL_MACRO(RTE_PTR_ALIGN);
> if (RTE_PTR_DIFF(BIGGER, SMALLER) != PTR_DIFF)
> FAIL_MACRO(RTE_PTR_DIFF);
> if (RTE_MAX(SMALLER, BIGGER) != BIGGER)
> diff --git a/lib/eal/include/rte_common.h
> b/lib/eal/include/rte_common.h
> index a96cc2a138..d517e9f75f 100644
> --- a/lib/eal/include/rte_common.h
> +++ b/lib/eal/include/rte_common.h
> @@ -295,7 +295,7 @@ static void
> __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
> /**
> * subtract a byte-value offset from a pointer
> */
> -#define RTE_PTR_SUB(ptr, x) ((void*)((uintptr_t)ptr - (x)))
> +#define RTE_PTR_SUB(ptr, x) ((void *)((uintptr_t)(ptr) - (x)))
>
> /**
> * get the difference between two pointer values, i.e. how far apart
> @@ -320,7 +320,7 @@ static void
> __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
> * must be a power-of-two value.
> */
> #define RTE_PTR_ALIGN_FLOOR(ptr, align) \
> - ((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)ptr, align))
> + ((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)(ptr), align))
>
> /**
> * Macro to align a value to a given power-of-two. The resultant value
> --
> 2.33.1
>
Reviewed-by: Morten Brørup <mb@smartsharesystems.com>
next prev parent reply other threads:[~2022-08-22 7:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-21 20:50 [PATCH 0/3] eal: small rte_common.h fixes and cleanup Dmitry Kozlyuk
2022-08-21 20:50 ` [PATCH 1/3] eal: fix pointer arithmetic with an expression argument Dmitry Kozlyuk
2022-08-22 7:14 ` Morten Brørup [this message]
2022-08-21 20:50 ` [PATCH 2/3] eal: uninline rte_str_to_size Dmitry Kozlyuk
2022-08-22 7:24 ` Morten Brørup
2022-08-22 14:06 ` Bruce Richardson
2022-08-21 20:50 ` [PATCH 3/3] eal: deduplicate roundup code Dmitry Kozlyuk
2022-08-22 7:25 ` Morten Brørup
2022-08-22 14:06 ` [PATCH 0/3] eal: small rte_common.h fixes and cleanup Bruce Richardson
2022-08-24 3:52 ` fengchengwen
2022-08-25 15:37 ` [PATCH v2 0/4] " Dmitry Kozlyuk
2022-08-25 15:37 ` [PATCH v2 1/4] eal: fix pointer arithmetic with an expression argument Dmitry Kozlyuk
2022-08-25 15:37 ` [PATCH v2 2/4] eal: deduplicate roundup code Dmitry Kozlyuk
2022-08-25 15:37 ` [PATCH v2 3/4] eal: uninline rte_str_to_size Dmitry Kozlyuk
2022-08-25 15:37 ` [PATCH v2 4/4] eal: remove unneeded includes from a public header Dmitry Kozlyuk
2022-08-25 22:33 ` [PATCH v3 0/4] eal: small rte_common.h fixes and cleanup Dmitry Kozlyuk
2022-08-25 22:33 ` [PATCH v3 1/4] eal: fix pointer arithmetic with an expression argument Dmitry Kozlyuk
2022-08-25 22:33 ` [PATCH v3 2/4] eal: deduplicate roundup code Dmitry Kozlyuk
2022-08-25 22:33 ` [PATCH v3 3/4] eal: uninline rte_str_to_size Dmitry Kozlyuk
2022-08-25 22:33 ` [PATCH v3 4/4] eal: remove unneeded includes from a public header Dmitry Kozlyuk
2022-08-27 11:32 ` [PATCH v4 0/4] eal: small rte_common.h fixes and cleanup Dmitry Kozlyuk
2022-08-27 11:32 ` [PATCH v4 1/4] eal: fix pointer arithmetic with an expression argument Dmitry Kozlyuk
2022-08-27 11:32 ` [PATCH v4 2/4] eal: deduplicate roundup code Dmitry Kozlyuk
2022-08-27 11:32 ` [PATCH v4 3/4] eal: uninline rte_str_to_size Dmitry Kozlyuk
2022-08-27 11:32 ` [PATCH v4 4/4] eal: remove unneeded includes from a public header Dmitry Kozlyuk
2022-08-29 8:29 ` Bruce Richardson
2022-09-21 9:27 ` David Marchand
2022-09-21 11:37 ` David Marchand
2022-09-21 13:30 ` [PATCH v4 0/4] eal: small rte_common.h fixes and cleanup David Marchand
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