kernel/linux.git/arch/x86/include/asm/text-patching.h, branch v5.15.210

x86/alternatives: Introduce int3_emulate_jcc()

2024-04-10T14:18:49+00:00

commit db7adcfd1cec4e95155e37bc066fddab302c6340 upstream. 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 Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

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

2024-03-01T12:21:49+00:00

Upstream commit: ba27d1a80871eb8dbeddf34ec7d396c149cbb8d7 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 Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Greg Kroah-Hartman

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

2024-03-01T12:21:49+00:00

Upstream commit: bbf92368b0b1fe472d489e62d3340d7897e9c697 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220308154317.638561109@infradead.org Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Greg Kroah-Hartman

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

x86/kprobes: Fix ordering while text-patching

2019-11-27T06:44:24+00:00

Kprobes does something like: register: arch_arm_kprobe() text_poke(INT3) /* guarantees nothing, INT3 will become visible at some point, maybe */ kprobe_optimizer() /* guarantees the bytes after INT3 are unused */ synchronize_rcu_tasks(); text_poke_bp(JMP32); /* implies IPI-sync, kprobe really is enabled */ unregister: __disarm_kprobe() unoptimize_kprobe() text_poke_bp(INT3 + tail); /* implies IPI-sync, so tail is guaranteed visible */ arch_disarm_kprobe() text_poke(old); /* guarantees nothing, old will maybe become visible */ synchronize_rcu() free-stuff Now the problem is that on register, the synchronize_rcu_tasks() does not imply sufficient to guarantee all CPUs have already observed INT3 (although in practice this is exceedingly unlikely not to have happened) (similar to how MEMBARRIER_CMD_PRIVATE_EXPEDITED does not imply MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE). Worse, even if it did, we'd have to do 2 synchronize calls to provide the guarantee we're looking for, the first to ensure INT3 is visible, the second to guarantee nobody is then still using the instruction bytes after INT3. Similar on unregister; the synchronize_rcu() between __unregister_kprobe_top() and __unregister_kprobe_bottom() does not guarantee all CPUs are free of the INT3 (and observe the old text). Therefore, sprinkle some IPI-sync love around. This guarantees that all CPUs agree on the text and RCU once again provides the required guaranteed. Tested-by: Alexei Starovoitov Tested-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mathieu Desnoyers Acked-by: Masami Hiramatsu Acked-by: Alexei Starovoitov Acked-by: Paul E. McKenney Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111132458.162172862@infradead.org Signed-off-by: Ingo Molnar

x86/kprobes: Convert to text-patching.h

2019-11-27T06:44:24+00:00

Convert kprobes to the new text-poke naming. Tested-by: Alexei Starovoitov Tested-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu Acked-by: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111132458.103959370@infradead.org Signed-off-by: Ingo Molnar

x86/ftrace: Use text_gen_insn()

2019-11-27T06:44:24+00:00

Replace the ftrace_code_union with the generic text_gen_insn() helper, which does exactly this. Tested-by: Alexei Starovoitov Tested-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Acked-by: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111132457.932808000@infradead.org Signed-off-by: Ingo Molnar

x86/alternative: Add text_opcode_size()

2019-11-27T06:44:24+00:00

Introduce a common helper to map *_INSN_OPCODE to *_INSN_SIZE. Tested-by: Alexei Starovoitov Tested-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Acked-by: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111132457.875666061@infradead.org Signed-off-by: Ingo Molnar

x86/alternatives: Add and use text_gen_insn() helper

2019-11-27T06:44:24+00:00

Provide a simple helper function to create common instruction encodings. Tested-by: Alexei Starovoitov Tested-by: Steven Rostedt (VMware) Signed-off-by: Peter Zijlstra (Intel) Acked-by: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Daniel Bristot de Oliveira Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Steven Rostedt Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111132457.703538332@infradead.org Signed-off-by: Ingo Molnar