From: "Jason A. Donenfeld" <Jason@zx2c4•com>
To: Christophe Leroy <christophe.leroy@csgroup•eu>
Cc: Theodore Ts'o <tytso@mit•edu>, Arnd Bergmann <arnd@arndb•de>,
Andy Lutomirski <luto@kernel•org>,
Thomas Gleixner <tglx@linutronix•de>,
Vincenzo Frascino <vincenzo.frascino@arm•com>,
Ingo Molnar <mingo@redhat•com>, Borislav Petkov <bp@alien8•de>,
Dave Hansen <dave.hansen@linux•intel.com>,
x86@kernel•org, "H. Peter Anvin" <hpa@zytor•com>,
linux-kernel@vger•kernel.org, linuxppc-dev@lists•ozlabs.org,
linux-arch@vger•kernel.org
Subject: Re: [PATCH 2/4] random: vDSO: Don't use PAGE_SIZE and PAGE_MASK
Date: Tue, 27 Aug 2024 09:49:58 +0200 [thread overview]
Message-ID: <Zs2FJku2hM2bp4ik@zx2c4.com> (raw)
In-Reply-To: <b8f8fb6d1d10386c74f2d8826b737a74c60b76b2.1724743492.git.christophe.leroy@csgroup.eu>
On Tue, Aug 27, 2024 at 09:31:48AM +0200, Christophe Leroy wrote:
> - ssize_t ret = min_t(size_t, INT_MAX & PAGE_MASK /* = MAX_RW_COUNT */, len);
> + const unsigned long page_size = 1UL << CONFIG_PAGE_SHIFT;
> + const unsigned long page_mask = ~(page_size - 1);
> + ssize_t ret = min_t(size_t, INT_MAX & page_mask /* = MAX_RW_COUNT */, len);
I'm really not a fan of making the code less idiomatic...
> An easy solution would be to define PAGE_SIZE and PAGE_MASK in vDSO
> when they do not exist already, but this can be misleading.
Why would what tglx and I suggested be misleading? That seems pretty
normal... Are you worried they might mismatch somehow? (If so, why?)
Jason
next prev parent reply other threads:[~2024-08-27 7:50 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-27 7:31 [PATCH 0/4] Fixups for random vDSO Christophe Leroy
2024-08-27 7:31 ` [PATCH 1/4] asm-generic/unaligned.h: Extract common header for vDSO Christophe Leroy
2024-08-27 7:31 ` [PATCH 2/4] random: vDSO: Don't use PAGE_SIZE and PAGE_MASK Christophe Leroy
2024-08-27 7:49 ` Jason A. Donenfeld [this message]
2024-08-27 8:16 ` Christophe Leroy
2024-08-27 8:23 ` Jason A. Donenfeld
2024-08-27 8:26 ` [PATCH] random: vDSO: Redefine " Christophe Leroy
2024-08-27 8:40 ` Jason A. Donenfeld
2024-08-27 8:55 ` Christophe Leroy
2024-08-27 9:59 ` Arnd Bergmann
2024-08-27 10:49 ` Christophe Leroy
2024-08-27 16:05 ` Vincenzo Frascino
2024-08-27 17:14 ` Christophe Leroy
2024-08-29 12:01 ` Vincenzo Frascino
2024-08-29 15:00 ` Christophe Leroy
2024-08-29 15:34 ` Vincenzo Frascino
2024-08-27 17:38 ` LEROY Christophe
2024-08-29 14:07 ` Vincenzo Frascino
2024-08-27 7:31 ` [PATCH 3/4] random: vDSO: Clean header inclusion in getrandom Christophe Leroy
2024-08-27 7:31 ` [PATCH 4/4] random: vDSO: don't use 64 bits atomics on 32 bits architectures Christophe Leroy
2024-08-27 8:03 ` Jason A. Donenfeld
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