From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: kernel-team@android.com, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Marc Zyngier <maz@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Russell King <rmk+kernel@armlinux.org.uk>
Subject: [PATCH 2/5] arm64: vdso: Remove redundant calls to flush_dcache_page()
Date: Thu, 18 Mar 2021 17:07:35 +0000 [thread overview]
Message-ID: <20210318170738.7756-3-will@kernel.org> (raw)
In-Reply-To: <20210318170738.7756-1-will@kernel.org>
flush_dcache_page() ensures that the 'PG_dcache_clean' flag for its
'page' argument is clear so that cache maintenance will be performed
if the page is mapped into userspace with execute permissions.
Newly allocated pages have this flag clear, so there is no need to call
flush_dcache_page() for the compat vdso or signal pages. Remove the
redundant calls.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/vdso.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 2d057a4dc787..421411981dc3 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -306,7 +306,6 @@ static int aarch32_alloc_kuser_vdso_page(void)
memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start,
kuser_sz);
aarch32_vectors_page = virt_to_page(vdso_page);
- flush_dcache_page(aarch32_vectors_page);
return 0;
}
@@ -322,7 +321,6 @@ static int aarch32_alloc_sigpage(void)
memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);
aarch32_sig_page = virt_to_page(sigpage);
- flush_dcache_page(aarch32_sig_page);
return 0;
}
--
2.31.0.rc2.261.g7f71774620-goog
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next prev parent reply other threads:[~2021-03-18 17:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 17:07 [PATCH 0/5] Minor improvements to the compat vdso and sigpage Will Deacon
2021-03-18 17:07 ` [PATCH 1/5] arm64: vdso: Use GFP_KERNEL for allocating compat vdso and signal pages Will Deacon
2021-03-18 18:03 ` Vincenzo Frascino
2021-03-24 17:28 ` Catalin Marinas
2021-03-18 17:07 ` Will Deacon [this message]
2021-03-18 18:05 ` [PATCH 2/5] arm64: vdso: Remove redundant calls to flush_dcache_page() Vincenzo Frascino
2021-03-18 17:07 ` [PATCH 3/5] arm64: compat: Allow signal page to be remapped Will Deacon
2021-03-18 18:06 ` Vincenzo Frascino
2021-03-18 17:07 ` [PATCH 4/5] arm64: vdso: Avoid ISB after reading from cntvct_el0 Will Deacon
2021-03-18 18:08 ` Vincenzo Frascino
2021-03-18 17:07 ` [PATCH 5/5] arm64: compat: Poison the compat sigpage Will Deacon
2021-03-18 18:13 ` Vincenzo Frascino
2021-03-24 16:58 ` [PATCH 0/5] Minor improvements to the compat vdso and sigpage Catalin Marinas
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