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authorSohil Mehta2023-09-14 18:58:03 +0000
committerArnd Bergmann2023-10-06 22:26:51 +0200
commit2fd0ebad27bcd4c8fc61c61a98d4283c47054bcf (patch)
treeeb28731e95f6d2ae674528a3376569a29a3a474d /arch/parisc
parentccab211af3c2b90ed792eb5f33707d2f0d59fe50 (diff)
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>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/kernel/syscalls/syscall.tbl1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 5410ff9456ae..4048ed480a04 100644
--- 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