arch: Reserve map_shadow_stack() syscall number for all architectures

commit c35559f94ebc ("x86/shstk: Introduce map_shadow_stack syscall")
recently added support for map_shadow_stack() but it is limited to x86
only for now. There is a possibility that other architectures (namely,
arm64 and RISC-V), that are implementing equivalent support for shadow
stacks, might need to add support for it.

Independent of that, reserving arch-specific syscall numbers in the
syscall tables of all architectures is good practice and would help
avoid future conflicts. map_shadow_stack() is marked as a conditional
syscall in sys_ni.c. Adding it to the syscall tables of other
architectures is harmless and would return ENOSYS when exercised.

Note, map_shadow_stack() was assigned #453 during the merge process
since #452 was taken by fchmodat2().

For Powerpc, map it to sys_ni_syscall() as is the norm for Powerpc
syscall tables.

For Alpha, map_shadow_stack() takes up #563 as Alpha still diverges from
the common syscall numbering system in the other architectures.

Link: https://lore.kernel.org/lkml/20230515212255.GA562920@debug.ba.rivosinc.com/
Link: https://lore.kernel.org/lkml/b402b80b-a7c6-4ef0-b977-c0f5f582b78a@sirena.org.uk/
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 26a32f8..5d05ab7 100644 (file)
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -492,3 +492,4 @@
 560    common  set_mempolicy_home_node         sys_ni_syscall
 561    common  cachestat                       sys_cachestat
 562    common  fchmodat2                       sys_fchmodat2
+563    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 04d8e49..45ec6e1 100644 (file)
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -466,3 +466,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index bd77253..6a28fb9 100644 (file)
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -39,7 +39,7 @@
 #define __ARM_NR_compat_set_tls                (__ARM_NR_COMPAT_BASE + 5)
 #define __ARM_NR_COMPAT_END            (__ARM_NR_COMPAT_BASE + 0x800)
 
-#define __NR_compat_syscalls           453
+#define __NR_compat_syscalls           454
 #endif
 
 #define __ARCH_WANT_SYS_CLONE

diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 9110be8..0774d9c 100644 (file)
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -911,6 +911,8 @@ __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node)
 __SYSCALL(__NR_cachestat, sys_cachestat)
 #define __NR_fchmodat2 452
 __SYSCALL(__NR_fchmodat2, sys_fchmodat2)
+#define __NR_map_shadow_stack 453
+__SYSCALL(__NR_map_shadow_stack, sys_map_shadow_stack)
 
 /*
  * Please add new compat syscalls above this comment and update

diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index f9d1f2d..12d0ce4 100644 (file)
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -452,3 +452,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 185fe73..de8219c 100644 (file)
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -458,3 +458,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 08f33e7..a5096a0 100644 (file)
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -391,3 +391,4 @@
 450    n32     set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    n32     cachestat                       sys_cachestat
 452    n32     fchmodat2                       sys_fchmodat2
+453    n32     map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 80be0e9..0044031 100644 (file)
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -367,3 +367,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    n64     cachestat                       sys_cachestat
 452    n64     fchmodat2                       sys_fchmodat2
+453    n64     map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 310c7e8..cf44a6a 100644 (file)
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -440,3 +440,4 @@
 450    o32     set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    o32     cachestat                       sys_cachestat
 452    o32     fchmodat2                       sys_fchmodat2
+453    o32     map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 5410ff9..4048ed4 100644 (file)
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -451,3 +451,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index e141251..d845e14 100644 (file)
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -539,3 +539,4 @@
 450    nospu   set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_ni_syscall

diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index cc0bc14..416645f 100644 (file)
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -455,3 +455,4 @@
 450  common    set_mempolicy_home_node sys_set_mempolicy_home_node     sys_set_mempolicy_home_node
 451  common    cachestat               sys_cachestat                   sys_cachestat
 452  common    fchmodat2               sys_fchmodat2                   sys_fchmodat2
+453  common    map_shadow_stack        sys_map_shadow_stack            sys_map_shadow_stack

diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 17ca589..bf36587 100644 (file)
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -455,3 +455,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 3f72970..f45f8c5 100644 (file)
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -498,3 +498,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 6d0286b..54748f6 100644 (file)
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -457,3 +457,4 @@
 450    i386    set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    i386    cachestat               sys_cachestat
 452    i386    fchmodat2               sys_fchmodat2
+453    i386    map_shadow_stack        sys_map_shadow_stack

diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 351521b..10a7eec 100644 (file)
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -423,3 +423,4 @@
 450    common  set_mempolicy_home_node         sys_set_mempolicy_home_node
 451    common  cachestat                       sys_cachestat
 452    common  fchmodat2                       sys_fchmodat2
+453    common  map_shadow_stack                sys_map_shadow_stack

diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 76d9464..00df5af 100644 (file)
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -823,8 +823,11 @@ __SYSCALL(__NR_cachestat, sys_cachestat)
 #define __NR_fchmodat2 452
 __SYSCALL(__NR_fchmodat2, sys_fchmodat2)
 
+#define __NR_map_shadow_stack 453
+__SYSCALL(__NR_map_shadow_stack, sys_map_shadow_stack)
+
 #undef __NR_syscalls
-#define __NR_syscalls 453
+#define __NR_syscalls 454
 
 /*
  * 32 bit systems traditionally used different