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| author | Sohil Mehta <sohil.mehta@intel.com> | 2023-09-14 18:58:03 +0000 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2023-10-06 22:26:51 +0200 |
| commit | 2fd0ebad27bcd4c8fc61c61a98d4283c47054bcf (patch) | |
| tree | eb28731e95f6d2ae674528a3376569a29a3a474d /arch/m68k | |
| parent | ccab211af3c2b90ed792eb5f33707d2f0d59fe50 (diff) | |
| download | lwn-2fd0ebad27bcd4c8fc61c61a98d4283c47054bcf.tar.gz lwn-2fd0ebad27bcd4c8fc61c61a98d4283c47054bcf.zip | |
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/m68k')
| -rw-r--r-- | arch/m68k/kernel/syscalls/syscall.tbl | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index f9d1f2d3f067..12d0ce43b094 100644 --- 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 |