linux.git/arch/x86/include/asm/text-patching.h, branch v6.8

x86/paravirt: Remove no longer needed paravirt patching code

2023-12-10T22:34:37+00:00

Now that paravirt is using the alternatives patching infrastructure,
remove the paravirt patching code.

Signed-off-by: Juergen Gross 
Signed-off-by: Borislav Petkov (AMD) 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20231210062138.2417-6-jgross@suse.com

x86/alternatives: Introduce int3_emulate_jcc()

2023-01-31T14:05:30+00:00

Move the kprobe Jcc emulation into int3_emulate_jcc() so it can be
used by more code -- specifically static_call() will need this.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Masami Hiramatsu (Google) 
Link: https://lore.kernel.org/r/20230123210607.057678245@infradead.org

x86/alternatives: Provide text_poke_copy_locked()

2022-10-17T14:41:11+00:00

The upcoming call thunk patching must hold text_mutex and needs access to
text_poke_copy(), which takes text_mutex.

Provide a _locked postfixed variant to expose the inner workings.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/r/20220915111147.159977224@infradead.org

x86/alternative: Introduce text_poke_set

2022-05-23T21:07:38+00:00

Introduce a memset like API for text_poke. This will be used to fill the
unused RX memory with illegal instructions.

Suggested-by: Peter Zijlstra (Intel) 
Signed-off-by: Song Liu 
Signed-off-by: Daniel Borkmann 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/bpf/20220520235758.1858153-3-song@kernel.org

Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-03-27T17:17:23+00:00

Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...

x86/ibt,paravirt: Use text_gen_insn() for paravirt_patch()

2022-03-15T09:32:34+00:00

Less duplication is more better.

Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Josh Poimboeuf 
Link: https://lore.kernel.org/r/20220308154317.697253958@infradead.org

x86/text-patching: Make text_gen_insn() play nice with ANNOTATE_NOENDBR

2022-03-15T09:32:33+00:00

Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Josh Poimboeuf 
Link: https://lore.kernel.org/r/20220308154317.638561109@infradead.org

x86/alternative: Introduce text_poke_copy

2022-02-08T02:13:01+00:00

This will be used by BPF jit compiler to dump JITed binary to a RX huge
page, and thus allow multiple BPF programs sharing the a huge (2MB) page.

Signed-off-by: Song Liu 
Signed-off-by: Alexei Starovoitov 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/bpf/20220204185742.271030-6-song@kernel.org

x86/alternatives: Teach text_poke_bp() to emulate RET

2020-09-01T07:58:05+00:00

Future patches will need to poke a RET instruction, provide the
infrastructure required for this.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Steven Rostedt (VMware) 
Cc: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20200818135804.982214828@infradead.org

x86/int3: Ensure that poke_int3_handler() is not traced

2020-06-11T13:14:52+00:00

In order to ensure poke_int3_handler() is completely self contained -- this
is called while modifying other text, imagine the fun of hitting another
INT3 -- ensure that everything it uses is not traced.

The primary means here is to force inlining; bsearch() is notrace because
all of lib/ is.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Alexandre Chartre 
Acked-by: Andy Lutomirski 
Link: https://lkml.kernel.org/r/20200505135313.410702173@linutronix.de