[PATCH v3 04/23] arm64: Use in_compat_task() in arch_setup_additional_pages()

[PATCH v3 04/23] arm64: Use in_compat_task() in arch_setup_additional_pages()

[Dmitry Safonov]

Instead of providing compat_arch_setup_additional_pages(), check if the
task is compatible from personality, which is set earlier in
load_elf_binary(). That will align code with powerpc and sparc, also
it'll allow to completely remove compat_arch_setyp_addtional_pages()
macro after doing the same for x86, simiplifying the binfmt code
in the end and leaving elf loader single function.

Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 arch/arm64/include/asm/elf.h |  5 -----
 arch/arm64/kernel/vdso.c     | 21 ++++++++++-----------
 2 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index d1073ffa7f24..a81953bcc1cf 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -237,11 +237,6 @@ do {									\
 #else
 #define COMPAT_ARCH_DLINFO
 #endif
-struct linux_binprm;
-extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
-					  int uses_interp);
-#define compat_arch_setup_additional_pages \
-					aarch32_setup_additional_pages
 
 #endif /* CONFIG_COMPAT */
 
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index a61fc4f989b3..a8bf72320ad0 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -411,29 +411,24 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
 	return PTR_ERR_OR_ZERO(ret);
 }
 
-int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+static int aarch32_setup_additional_pages(struct linux_binprm *bprm,
+					  int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
 	int ret;
 
-	if (mmap_write_lock_killable(mm))
-		return -EINTR;
-
 	ret = aarch32_kuser_helpers_setup(mm);
 	if (ret)
-		goto out;
+		return ret;
 
 	if (IS_ENABLED(CONFIG_COMPAT_VDSO)) {
 		ret = __setup_additional_pages(VDSO_ABI_AA32, mm, bprm,
 					       uses_interp);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
-	ret = aarch32_sigreturn_setup(mm);
-out:
-	mmap_write_unlock(mm);
-	return ret;
+	return aarch32_sigreturn_setup(mm);
 }
 #endif /* CONFIG_COMPAT */
 
@@ -470,7 +465,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	ret = __setup_additional_pages(VDSO_ABI_AA64, mm, bprm, uses_interp);
+	if (is_compat_task())
+		ret = aarch32_setup_additional_pages(bprm, uses_interp);
+	else
+		ret = __setup_additional_pages(VDSO_ABI_AA64, mm, bprm, uses_interp);
+
 	mmap_write_unlock(mm);
 
 	return ret;
-- 
2.31.1


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Re: [PATCH v3 04/23] arm64: Use in_compat_task() in arch_setup_additional_pages()

[Will Deacon]

On Fri, Jun 11, 2021 at 07:02:23PM +0100, Dmitry Safonov wrote:
> Instead of providing compat_arch_setup_additional_pages(), check if the
> task is compatible from personality, which is set earlier in
> load_elf_binary(). That will align code with powerpc and sparc, also
> it'll allow to completely remove compat_arch_setyp_addtional_pages()
> macro after doing the same for x86, simiplifying the binfmt code
> in the end and leaving elf loader single function.
> 
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> ---
>  arch/arm64/include/asm/elf.h |  5 -----
>  arch/arm64/kernel/vdso.c     | 21 ++++++++++-----------
>  2 files changed, 10 insertions(+), 16 deletions(-)

Acked-by: Will Deacon <will@kernel.org>

Will

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