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Message-Id: <20180618150613.10322-23-salyzyn@android.com>
Date: Mon, 18 Jun 2018 08:06:08 -0700
From: Mark Salyzyn <salyzyn@...roid.com>
To: linux-kernel@...r.kernel.org
Cc: Kevin Brodsky <kevin.brodsky@....com>,
Mark Salyzyn <salyzyn@...roid.com>,
James Morse <james.morse@....com>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Andy Lutomirski <luto@...capital.net>,
Dmitry Safonov <dsafonov@...tuozzo.com>,
John Stultz <john.stultz@...aro.org>,
Mark Rutland <mark.rutland@....com>,
Laura Abbott <labbott@...hat.com>,
Kees Cook <keescook@...omium.org>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Andy Gross <andy.gross@...aro.org>,
Andrew Pinski <apinski@...ium.com>,
Thomas Gleixner <tglx@...utronix.de>,
linux-arm-kernel@...ts.infradead.org,
Jeremy Linton <Jeremy.Linton@....com>
Subject: RESEND [PATCH 5/6] arm64: compat: 32-bit vDSO setup
From: Kevin Brodsky <kevin.brodsky@....com>
If the compat vDSO is enabled, install it in compat processes. In this
case, the compat vDSO replaces the sigreturn page (it provides its own
sigreturn trampolines).
Signed-off-by: Kevin Brodsky <kevin.brodsky@....com>
Signed-off-by: Mark Salyzyn <salyzyn@...roid.com>
Cc: James Morse <james.morse@....com>
Cc: Russell King <linux@...linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dmitry Safonov <dsafonov@...tuozzo.com>
Cc: John Stultz <john.stultz@...aro.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Laura Abbott <labbott@...hat.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: Andy Gross <andy.gross@...aro.org>
Cc: Andrew Pinski <apinski@...ium.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-kernel@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org
Cc: Jeremy Linton <Jeremy.Linton@....com>
---
arch/arm64/kernel/vdso.c | 55 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 8529e85a521f..9fb1e0d380ab 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -58,6 +58,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
/*
* Create and map the vectors page for AArch32 tasks.
*/
+#if !defined(CONFIG_VDSO32) || defined(CONFIG_KUSER_HELPERS)
static struct page *vectors_page[] __ro_after_init;
static const struct vm_special_mapping compat_vdso_spec[] = {
{
@@ -73,6 +74,7 @@ static const struct vm_special_mapping compat_vdso_spec[] = {
#endif
};
static struct page *vectors_page[ARRAY_SIZE(compat_vdso_spec)] __ro_after_init;
+#endif
static int __init alloc_vectors_page(void)
{
@@ -82,6 +84,7 @@ static int __init alloc_vectors_page(void)
unsigned long kuser_vpage;
#endif
+#ifndef CONFIG_VDSO32
extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
size_t sigret_sz =
__aarch32_sigret_code_end - __aarch32_sigret_code_start;
@@ -90,19 +93,24 @@ static int __init alloc_vectors_page(void)
sigret_vpage = get_zeroed_page(GFP_ATOMIC);
if (!sigret_vpage)
return -ENOMEM;
+#endif
#ifdef CONFIG_KUSER_HELPERS
kuser_vpage = get_zeroed_page(GFP_ATOMIC);
if (!kuser_vpage) {
+#ifndef CONFIG_VDSO32
free_page(sigret_vpage);
+#endif
return -ENOMEM;
}
#endif
+#ifndef CONFIG_VDSO32
/* sigreturn code */
memcpy((void *)sigret_vpage, __aarch32_sigret_code_start, sigret_sz);
flush_icache_range(sigret_vpage, sigret_vpage + PAGE_SIZE);
vectors_page[0] = virt_to_page(sigret_vpage);
+#endif
#ifdef CONFIG_KUSER_HELPERS
/* kuser helpers */
@@ -116,6 +124,7 @@ static int __init alloc_vectors_page(void)
}
arch_initcall(alloc_vectors_page);
+#ifndef CONFIG_VDSO32
int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
@@ -151,6 +160,7 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
return PTR_ERR_OR_ZERO(ret);
}
+#endif /* !CONFIG_VDSO32 */
#endif /* CONFIG_COMPAT */
static int vdso_mremap(const struct vm_special_mapping *sm,
@@ -221,6 +231,23 @@ static int __init vdso_mappings_init(const char *name,
return 0;
}
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_VDSO32
+
+static struct vdso_mappings vdso32_mappings __ro_after_init;
+
+static int __init vdso32_init(void)
+{
+ extern char vdso32_start[], vdso32_end[];
+
+ return vdso_mappings_init("vdso32", vdso32_start, vdso32_end,
+ &vdso32_mappings);
+}
+arch_initcall(vdso32_init);
+
+#endif /* CONFIG_VDSO32 */
+#endif /* CONFIG_COMPAT */
+
static struct vdso_mappings vdso_mappings __ro_after_init;
static int __init vdso_init(void)
@@ -263,6 +290,34 @@ static int vdso_setup(struct mm_struct *mm,
return PTR_ERR_OR_ZERO(ret);
}
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_VDSO32
+int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
+{
+ struct mm_struct *mm = current->mm;
+ void *ret;
+
+ if (down_write_killable(&mm->mmap_sem))
+ return -EINTR;
+
+ ret = ERR_PTR(vdso_setup(mm, &vdso32_mappings));
+#ifdef CONFIG_KUSER_HELPERS
+ if (!IS_ERR(ret))
+ /* Map the kuser helpers at the ABI-defined high address. */
+ ret = _install_special_mapping(mm, AARCH32_KUSER_HELPERS_BASE,
+ PAGE_SIZE,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYEXEC,
+ &compat_vdso_spec[1]);
+#endif
+
+ up_write(&mm->mmap_sem);
+
+ return PTR_ERR_OR_ZERO(ret);
+}
+#endif /* CONFIG_VDSO32 */
+#endif /* CONFIG_COMPAT */
+
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
--
2.18.0.rc1.244.gcf134e6275-goog
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