[PATCH 0/5] x86/bugs: more BHI fixes

[Josh Poimboeuf <jpoimboe@kernel.org>]

Patch 1 is another iteration of reducing the scope of syscall hardening
in order to improve performance on some CPUs.  The feature bit has a new
name, and the commit log and comments are much improved.

The rest of the patches are new:

  - Patch 2 fixes the default mitigations for !x86 (reimplementation of
    Sean's fix).

  - Patch 3 fixes some objtool warnings found by Paul.

  - Patch 4 is a documentation cleanup and prep for patch 5.

  - Patch 5 adds a requested spectre_bhi=vmexit option.

Josh Poimboeuf (5):
  x86/bugs: Only harden syscalls when needed
  cpu/speculation: Fix CPU mitigation defaults for !x86
  x86/syscall: Mark exit[_group] syscall handlers __noreturn
  x86/bugs: Remove duplicate Spectre cmdline option descriptions
  x86/bugs: Add 'spectre_bhi=vmexit' cmdline option

 Documentation/admin-guide/hw-vuln/spectre.rst | 84 ++-----------------
 .../admin-guide/kernel-parameters.txt         | 12 ++-
 arch/Kconfig                                  | 10 +++
 arch/x86/Kconfig                              | 15 +---
 arch/x86/entry/common.c                       | 15 +++-
 arch/x86/entry/syscall_32.c                   | 11 +--
 arch/x86/entry/syscall_64.c                   | 10 +--
 arch/x86/entry/syscall_x32.c                  | 11 ++-
 arch/x86/entry/syscalls/syscall_64.tbl        |  6 +-
 arch/x86/include/asm/cpufeatures.h            |  1 +
 arch/x86/include/asm/syscall.h                |  8 +-
 arch/x86/kernel/cpu/bugs.c                    | 51 +++++++++--
 arch/x86/um/sys_call_table_32.c               |  1 +
 arch/x86/um/sys_call_table_64.c               |  1 +
 kernel/cpu.c                                  |  4 +-
 scripts/syscalltbl.sh                         |  6 +-
 tools/objtool/noreturns.h                     |  4 +
 17 files changed, 126 insertions(+), 124 deletions(-)

-- 
2.44.0