From: Michael Ellerman <mpe@ellerman.id.au>
To: Mathieu Malaterre <malat@debian.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>, Jiri Slaby <jslaby@suse.com>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Mathieu Malaterre <malat@debian.org>
Subject: Re: [PATCH 05/21] powerpc: Avoid comparison of unsigned long >= 0 in pfn_valid
Date: Sun, 04 Mar 2018 21:55:17 +1100 [thread overview]
Message-ID: <87lgf8gley.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20180225172236.29650-6-malat@debian.org>
Mathieu Malaterre <malat@debian.org> writes:
> Rewrite comparison since all values compared are of type `unsigned long`.
>
> Fix a warning (treated as error in W=3D1):
>
> CC arch/powerpc/kernel/irq.o
> In file included from ./include/linux/bug.h:5:0,
> from ./include/linux/cpumask.h:13,
> from ./include/linux/smp.h:13,
> from ./include/linux/kernel_stat.h:5,
> from arch/powerpc/kernel/irq.c:35:
> ./include/linux/dma-mapping.h: In function =E2=80=98dma_map_resource=E2=
=80=99:
> ./arch/powerpc/include/asm/page.h:129:32: error: comparison of unsigned e=
xpression >=3D 0 is always true [-Werror=3Dtype-limits]
> #define pfn_valid(pfn) ((pfn) >=3D ARCH_PFN_OFFSET && (pfn) < max_mapnr)
> ^
> Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> ---
> arch/powerpc/include/asm/page.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/p=
age.h
> index 8da5d4c1cab2..19dea64e7ed2 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -126,7 +126,8 @@ extern long long virt_phys_offset;
>=20=20
> #ifdef CONFIG_FLATMEM
> #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
> -#define pfn_valid(pfn) ((pfn) >=3D ARCH_PFN_OFFSET && (pfn) < max_mapnr)
> +#define pfn_valid(pfn) \
> + (((pfn) - ARCH_PFN_OFFSET) < (max_mapnr - ARCH_PFN_OFFSET))
I'm not a big fan of this one, because the original code is *far* more
obvious as to what it's doing.
I'm not sure if we can make this one a static inline, or whether that
would help, but it would be worth investigating.
cheers
next prev parent reply other threads:[~2018-03-04 10:55 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-25 17:22 [PATCH 00/21] powerpc/gamecube: make W=1 compilation errors free Mathieu Malaterre
2018-02-25 17:22 ` [PATCH 01/21] powerpc: Remove warning on array size when empty Mathieu Malaterre
2018-02-25 18:53 ` Segher Boessenkool
2018-02-26 14:44 ` Andy Shevchenko
2018-02-26 14:45 ` Andy Shevchenko
2018-02-27 7:25 ` Mathieu Malaterre
2018-02-27 7:33 ` Christophe LEROY
2018-02-27 7:44 ` Mathieu Malaterre
2018-02-27 15:52 ` Andy Shevchenko
2018-02-27 17:25 ` Mathieu Malaterre
2018-02-27 20:42 ` Segher Boessenkool
2018-02-28 15:50 ` Andy Shevchenko
2018-03-01 2:55 ` Michael Ellerman
2018-03-01 7:01 ` Mathieu Malaterre
2018-03-01 9:33 ` Michael Ellerman
2018-03-02 19:49 ` [PATCH v2 " Mathieu Malaterre
2018-03-14 9:28 ` [v2,01/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 02/21] powerpc: Move the inline keyword at the beginning of function declaration Mathieu Malaterre
2018-03-14 9:27 ` [02/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 03/21] powerpc: Mark the variable earlycon_acpi_spcr_enable maybe_unused Mathieu Malaterre
2018-03-04 10:54 ` Michael Ellerman
2018-03-10 18:08 ` Mathieu Malaterre
2018-02-25 17:22 ` [PATCH 04/21] powerpc: Mark both tmp variables as unused Mathieu Malaterre
2018-03-14 9:27 ` [04/21] " Michael Ellerman
2018-03-14 10:38 ` [PATCH 04/21] " Christophe LEROY
2018-03-16 14:08 ` Michael Ellerman
2018-02-25 17:22 ` [PATCH 05/21] powerpc: Avoid comparison of unsigned long >= 0 in pfn_valid Mathieu Malaterre
2018-02-26 6:32 ` Christophe LEROY
2018-02-26 7:49 ` Mathieu Malaterre
2018-02-26 8:46 ` Segher Boessenkool
2018-03-02 19:54 ` Mathieu Malaterre
2018-03-03 7:45 ` christophe leroy
2018-03-04 10:55 ` Michael Ellerman [this message]
2018-03-04 19:46 ` christophe leroy
2018-03-07 20:34 ` [PATCH v2 " Mathieu Malaterre
2018-03-14 9:28 ` [v2, " Michael Ellerman
2018-02-25 17:22 ` [PATCH 06/21] powerpc: Avoid comparison of unsigned long >= 0 in __access_ok Mathieu Malaterre
2018-02-26 6:34 ` Christophe LEROY
2018-02-26 6:50 ` Christophe LEROY
2018-02-26 7:44 ` Mathieu Malaterre
2018-02-26 17:50 ` Mathieu Malaterre
2018-02-26 20:00 ` christophe leroy
2018-02-26 22:17 ` Segher Boessenkool
2018-03-02 19:50 ` [PATCH v2 " Mathieu Malaterre
2018-03-03 7:44 ` christophe leroy
2018-03-14 9:28 ` [v2, " Michael Ellerman
2018-02-25 17:22 ` [PATCH 07/21] powerpc: Make functions flipper_pic_init & ug_udbg_putc static Mathieu Malaterre
2018-03-14 9:27 ` [07/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 08/21] powerpc: Make function __giveup_fpu static Mathieu Malaterre
2018-03-14 9:28 ` [08/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 09/21] powerpc: Make function save_all static Mathieu Malaterre
2018-02-25 17:22 ` [PATCH 10/21] powerpc: Add missing prototype for slb_miss_bad_addr Mathieu Malaterre
2018-03-14 9:27 ` [10/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 11/21] powerpc: Add missing prototype for hdec_interrupt Mathieu Malaterre
2018-03-14 9:27 ` [11/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 12/21] powerpc: Add missing prototype for time_init Mathieu Malaterre
2018-03-14 9:27 ` [12/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 13/21] powerpc: Add missing prototype for arch_dup_task_struct Mathieu Malaterre
2018-03-14 9:27 ` [13/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 14/21] powerpc: Add missing prototype for arch_irq_work_raise Mathieu Malaterre
2018-03-14 9:27 ` [14/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 15/21] powerpc: Add missing prototype for MMU_setup Mathieu Malaterre
2018-03-04 10:54 ` Michael Ellerman
2018-03-07 20:32 ` [PATCH v2 15/21] powerpc: Make function MMU_setup static Mathieu Malaterre
2018-03-14 9:28 ` [v2,15/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 16/21] powerpc: Add missing prototype for init_IRQ Mathieu Malaterre
2018-03-14 9:28 ` [16/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 17/21] powerpc: Add missing prototype for sys_debug_setcontext Mathieu Malaterre
2018-03-04 10:54 ` Michael Ellerman
2018-03-07 20:37 ` Mathieu Malaterre
2018-03-08 10:36 ` Michael Ellerman
2018-03-26 18:56 ` Mathieu Malaterre
2018-03-27 8:50 ` Michael Ellerman
2018-03-14 9:28 ` [17/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 18/21] powerpc: Add missing prototypes for sys_sigreturn & sys_rt_sigreturn Mathieu Malaterre
2018-03-14 9:28 ` [18/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 19/21] powerpc: Add missing prototypes for hw_breakpoint_handler & arch_unregister_hw_breakpoint Mathieu Malaterre
2018-03-14 9:28 ` [19/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 20/21] powerpc: Add missing prototypes for ppc_select & ppc_fadvise64_64 Mathieu Malaterre
2018-03-14 9:28 ` [20/21] " Michael Ellerman
2018-02-25 17:22 ` [PATCH 21/21] powerpc: Add missing prototypes in setup_32.c Mathieu Malaterre
2018-03-08 11:44 ` Michael Ellerman
2018-03-14 9:28 ` [21/21] " Michael Ellerman
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