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 5/5] arm64: compat: Poison the compat sigpage
Date: Thu, 18 Mar 2021 17:07:38 +0000 [thread overview]
Message-ID: <20210318170738.7756-6-will@kernel.org> (raw)
In-Reply-To: <20210318170738.7756-1-will@kernel.org>
Commit 9c698bff66ab ("ARM: ensure the signal page contains defined contents")
poisoned the unused portions of the signal page for 32-bit Arm.
Implement the same poisoning for the compat signal page on arm64 rather
than using __GFP_ZERO.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/vdso.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 16bf0b46fb70..159b72a646ab 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -318,17 +318,20 @@ static int aarch32_alloc_kuser_vdso_page(void)
return 0;
}
+#define COMPAT_SIGPAGE_POISON_WORD 0xe7fddef1
static int aarch32_alloc_sigpage(void)
{
extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
- unsigned long sigpage;
+ __le32 poison = cpu_to_le32(COMPAT_SIGPAGE_POISON_WORD);
+ void *sigpage;
- sigpage = get_zeroed_page(GFP_KERNEL);
+ sigpage = (void *)__get_free_page(GFP_KERNEL);
if (!sigpage)
return -ENOMEM;
- memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);
+ memset32(sigpage, (__force u32)poison, PAGE_SIZE / sizeof(poison));
+ memcpy(sigpage, __aarch32_sigret_code_start, sigret_sz);
aarch32_sig_page = virt_to_page(sigpage);
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 ` [PATCH 2/5] arm64: vdso: Remove redundant calls to flush_dcache_page() Will Deacon
2021-03-18 18:05 ` 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 ` Will Deacon [this message]
2021-03-18 18:13 ` [PATCH 5/5] arm64: compat: Poison the compat sigpage Vincenzo Frascino
2021-03-24 16:58 ` [PATCH 0/5] Minor improvements to the compat vdso and sigpage Catalin Marinas
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