Thread (13 messages) 13 messages, 2 authors, 2020-12-01

[PATCH v13 09/10] arch, mm: wire up memfd_secret system call were relevant

flat view
STALE2139d REVIEWED: 6 (5M)

From: Mike Rapoport <rppt@kernel.org>
Date: 2020-12-01 07:49:00
Also in: linux-arch, linux-arm-kernel, linux-fsdevel, linux-kselftest, linux-mm, linux-riscv, lkml, nvdimm
Subsystem: abi/api, arm64 port (aarch64 architecture), generic include/asm header files, memory management, memory management - secretmem, risc-v architecture, the rest, x86 architecture (32-bit and 64-bit), x86 entry code · Maintainers: Catalin Marinas, Will Deacon, Arnd Bergmann, Andrew Morton, Mike Rapoport, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski

Revision v13 of 11 in this series; 2 review trailers (1 from subsystem maintainers).

Revisions (11)
  1. v8 [diff vs current]
  2. v9 [diff vs current]
  3. v10 [diff vs current]
  4. v11 [diff vs current]
  5. v12 [diff vs current]
  6. v13 current
  7. v14 [diff vs current]
  8. v15 [diff vs current]
  9. v16 [diff vs current]
  10. v17 [diff vs current]
  11. v18 [diff vs current]
From: Mike Rapoport <redacted>

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 <redacted>
Acked-by: Palmer Dabbelt <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
 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      | 6 +++++-
 mm/secretmem.c                         | 3 +++
 scripts/checksyscalls.sh               | 4 ++++
 8 files changed, 17 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 c52ab1c4a755..109e6681b8fa 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -446,3 +446,4 @@
 439	i386	faccessat2		sys_faccessat2
 440	i386	process_madvise		sys_process_madvise
 441	i386	watch_mount		sys_watch_mount
+442	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 f3270a9ef467..742cf17d7725 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -363,6 +363,7 @@
 439	common	faccessat2		sys_faccessat2
 440	common	process_madvise		sys_process_madvise
 441	common	watch_mount		sys_watch_mount
+442	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 6d55324363ab..f9d93fbf9b69 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1010,6 +1010,7 @@ asmlinkage long sys_pidfd_send_signal(int pidfd, int sig,
 asmlinkage long sys_pidfd_getfd(int pidfd, int fd, unsigned int flags);
 asmlinkage long sys_watch_mount(int dfd, const char __user *path,
 				unsigned int at_flags, int watch_fd, int watch_id);
+asmlinkage long sys_memfd_secret(unsigned long flags);
 
 /*
  * Architecture-specific system calls
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 5df46517260e..51151888f330 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -861,9 +861,13 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
 __SYSCALL(__NR_process_madvise, sys_process_madvise)
 #define __NR_watch_mount 441
 __SYSCALL(__NR_watch_mount, sys_watch_mount)
+#ifdef __ARCH_WANT_MEMFD_SECRET
+#define __NR_memfd_secret 442
+__SYSCALL(__NR_memfd_secret, sys_memfd_secret)
+#endif
 
 #undef __NR_syscalls
-#define __NR_syscalls 442
+#define __NR_syscalls 443
 
 /*
  * 32 bit systems traditionally used different
diff --git a/mm/secretmem.c b/mm/secretmem.c
index 2cf5cc79418b..ecd7a586af8e 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -415,6 +415,9 @@ static int __init secretmem_setup(char *str)
 	unsigned long reserved_size;
 	int err;
 
+	if (!can_set_direct_map())
+		return 0;
+
 	reserved_size = memparse(str, NULL);
 	if (!reserved_size)
 		return 0;
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 */
 
-- 
2.28.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help