Re: [PATCH v19 7/8] arch, mm: wire up memfd_secret system call where relevant

[David Hildenbrand]

On 13.05.21 20:47, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> Wire up memfd_secret system call on architectures that define
> ARCH_HAS_SET_DIRECT_MAP, namely arm64, risc-v and x86.
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> Acked-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Christopher Lameter <cl@xxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Elena Reshetova <elena.reshetova@xxxxxxxxx>
> Cc: Hagen Paul Pfeifer <hagen@xxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: James Bottomley <jejb@xxxxxxxxxxxxx>
> Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> Cc: Roman Gushchin <guro@xxxxxx>
> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
> Cc: Shuah Khan <shuah@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Tycho Andersen <tycho@xxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> ---
>   arch/arm64/include/uapi/asm/unistd.h   | 1 +
>   arch/riscv/include/asm/unistd.h        | 1 +
>   arch/x86/entry/syscalls/syscall_32.tbl | 1 +
>   arch/x86/entry/syscalls/syscall_64.tbl | 1 +
>   include/linux/syscalls.h               | 1 +
>   include/uapi/asm-generic/unistd.h      | 7 ++++++-
>   scripts/checksyscalls.sh               | 4 ++++
>   7 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/uapi/asm/unistd.h b/arch/arm64/include/uapi/asm/unistd.h
> index f83a70e07df8..ce2ee8f1e361 100644
> --- a/arch/arm64/include/uapi/asm/unistd.h
> +++ b/arch/arm64/include/uapi/asm/unistd.h
> @@ -20,5 +20,6 @@
>   #define __ARCH_WANT_SET_GET_RLIMIT
>   #define __ARCH_WANT_TIME32_SYSCALLS
>   #define __ARCH_WANT_SYS_CLONE3
> +#define __ARCH_WANT_MEMFD_SECRET
>   
>   #include <asm-generic/unistd.h>
> diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
> index 977ee6181dab..6c316093a1e5 100644
> --- a/arch/riscv/include/asm/unistd.h
> +++ b/arch/riscv/include/asm/unistd.h
> @@ -9,6 +9,7 @@
>    */
>   
>   #define __ARCH_WANT_SYS_CLONE
> +#define __ARCH_WANT_MEMFD_SECRET
>   
>   #include <uapi/asm/unistd.h>
>   
> diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
> index 28a1423ce32e..e44519020a43 100644
> --- a/arch/x86/entry/syscalls/syscall_32.tbl
> +++ b/arch/x86/entry/syscalls/syscall_32.tbl
> @@ -451,3 +451,4 @@
>   444	i386	landlock_create_ruleset	sys_landlock_create_ruleset
>   445	i386	landlock_add_rule	sys_landlock_add_rule
>   446	i386	landlock_restrict_self	sys_landlock_restrict_self
> +447	i386	memfd_secret		sys_memfd_secret
> diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
> index ecd551b08d05..a06f16106f24 100644
> --- a/arch/x86/entry/syscalls/syscall_64.tbl
> +++ b/arch/x86/entry/syscalls/syscall_64.tbl
> @@ -368,6 +368,7 @@
>   444	common	landlock_create_ruleset	sys_landlock_create_ruleset
>   445	common	landlock_add_rule	sys_landlock_add_rule
>   446	common	landlock_restrict_self	sys_landlock_restrict_self
> +447	common	memfd_secret		sys_memfd_secret
>   
>   #
>   # Due to a historical design error, certain syscalls are numbered differently
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index 050511e8f1f8..1a1b5d724497 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -1050,6 +1050,7 @@ asmlinkage long sys_landlock_create_ruleset(const struct landlock_ruleset_attr _
>   asmlinkage long sys_landlock_add_rule(int ruleset_fd, enum landlock_rule_type rule_type,
>   		const void __user *rule_attr, __u32 flags);
>   asmlinkage long sys_landlock_restrict_self(int ruleset_fd, __u32 flags);
> +asmlinkage long sys_memfd_secret(unsigned int flags);
>   
>   /*
>    * Architecture-specific system calls
> diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
> index 6de5a7fc066b..28b388368cf6 100644
> --- a/include/uapi/asm-generic/unistd.h
> +++ b/include/uapi/asm-generic/unistd.h
> @@ -873,8 +873,13 @@ __SYSCALL(__NR_landlock_add_rule, sys_landlock_add_rule)
>   #define __NR_landlock_restrict_self 446
>   __SYSCALL(__NR_landlock_restrict_self, sys_landlock_restrict_self)
>   
> +#ifdef __ARCH_WANT_MEMFD_SECRET
> +#define __NR_memfd_secret 447
> +__SYSCALL(__NR_memfd_secret, sys_memfd_secret)
> +#endif
> +
>   #undef __NR_syscalls
> -#define __NR_syscalls 447
> +#define __NR_syscalls 448
>   
>   /*
>    * 32 bit systems traditionally used different
> diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh
> index a18b47695f55..b7609958ee36 100755
> --- a/scripts/checksyscalls.sh
> +++ b/scripts/checksyscalls.sh
> @@ -40,6 +40,10 @@ cat << EOF
>   #define __IGNORE_setrlimit	/* setrlimit */
>   #endif
>   
> +#ifndef __ARCH_WANT_MEMFD_SECRET
> +#define __IGNORE_memfd_secret
> +#endif
> +
>   /* Missing flags argument */
>   #define __IGNORE_renameat	/* renameat2 */
>   

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Thanks,

David / dhildenb