From: Vincenzo Frascino <vincenzo.frascino@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>
Subject: [PATCH v4 3/4] arm64: compat: Refactor aarch32_alloc_vdso_pages()
Date: Mon, 15 Apr 2019 10:49:36 +0100 [thread overview]
Message-ID: <20190415094937.13518-4-vincenzo.frascino@arm.com> (raw)
In-Reply-To: <20190415094937.13518-1-vincenzo.frascino@arm.com>
aarch32_alloc_vdso_pages() needs to be refactored to make it
easier to disable kuser helpers.
Divide the function in aarch32_alloc_kuser_vdso_page() and
aarch32_alloc_sigreturn_vdso_page().
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/kernel/vdso.c | 73 ++++++++++++++++++++++++++--------------
1 file changed, 48 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 79fd7a65ae55..22e8b039cfe6 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -77,46 +77,69 @@ static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = {
},
};
-static int __init aarch32_alloc_vdso_pages(void)
+static int aarch32_alloc_kuser_vdso_page(void)
{
extern char __kuser_helper_start[], __kuser_helper_end[];
- extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
-
int kuser_sz = __kuser_helper_end - __kuser_helper_start;
- int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
- unsigned long vdso_pages[C_PAGES];
+ unsigned long vdso_page;
- vdso_pages[C_VECTORS] = get_zeroed_page(GFP_ATOMIC);
- if (!vdso_pages[C_VECTORS])
+ vdso_page = get_zeroed_page(GFP_ATOMIC);
+ if (!vdso_page)
return -ENOMEM;
- vdso_pages[C_SIGPAGE] = get_zeroed_page(GFP_ATOMIC);
- if (!vdso_pages[C_SIGPAGE]) {
- /*
- * free_page() it is required to avoid to leak the vectors page
- * if the allocation of sigpage fails.
- */
- free_page(vdso_pages[C_VECTORS]);
- return -ENOMEM;
- }
-
/* kuser helpers */
- memcpy((void *)(vdso_pages[C_VECTORS] + 0x1000 - kuser_sz),
+ memcpy((void *)(vdso_page + 0x1000 - kuser_sz),
__kuser_helper_start,
kuser_sz);
+ aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_page);
+
+ flush_dcache_page(aarch32_vdso_pages[C_VECTORS]);
+
+ return 0;
+}
+
+static int aarch32_alloc_sigreturn_vdso_page(void)
+{
+ extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
+ int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
+ unsigned long vdso_page;
+
+ vdso_page = get_zeroed_page(GFP_ATOMIC);
+ if (!vdso_page)
+ return -ENOMEM;
+
/* sigreturn code */
- memcpy((void *)vdso_pages[C_SIGPAGE],
+ memcpy((void *)vdso_page,
__aarch32_sigret_code_start,
sigret_sz);
- flush_icache_range(vdso_pages[C_VECTORS],
- vdso_pages[C_VECTORS] + PAGE_SIZE);
- flush_icache_range(vdso_pages[C_SIGPAGE],
- vdso_pages[C_SIGPAGE] + PAGE_SIZE);
+ aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(vdso_page);
+
+ flush_dcache_page(aarch32_vdso_pages[C_SIGPAGE]);
+
+ return 0;
+}
+
+static int __init aarch32_alloc_vdso_pages(void)
+{
+ int ret;
+
+ ret = aarch32_alloc_kuser_vdso_page();
+ if (ret)
+ return ret;
- aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_pages[C_VECTORS]);
- aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(vdso_pages[C_SIGPAGE]);
+ ret = aarch32_alloc_sigreturn_vdso_page();
+ if (ret) {
+ unsigned long vectors_addr = (unsigned long)page_to_virt(
+ aarch32_vdso_pages[C_VECTORS]);
+ /*
+ * free_page() it is required to avoid to leak the vectors page
+ * if the allocation of sigpage fails.
+ */
+ free_page(vectors_addr);
+ return ret;
+ }
return 0;
}
--
2.21.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-15 9:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 9:49 [PATCH v4 0/4] arm64: compat: Add kuser helpers config option Vincenzo Frascino
2019-04-15 9:49 ` [PATCH v4 1/4] arm64: compat: Alloc separate pages for vectors and sigpage Vincenzo Frascino
2019-04-15 9:49 ` [PATCH v4 2/4] arm64: compat: Split kuser32 Vincenzo Frascino
2019-04-15 9:49 ` Vincenzo Frascino [this message]
2019-04-15 9:49 ` [PATCH v4 4/4] arm64: compat: Add KUSER_HELPERS config option Vincenzo Frascino
2019-04-16 21:35 ` [PATCH v4 0/4] arm64: compat: Add kuser helpers " Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190415094937.13518-4-vincenzo.frascino@arm.com \
--to=vincenzo.frascino@arm.com \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox