Adrian Hunter
a44abd2c4c
perf intel pt: Add new JMPABS instruction to the Intel PT instruction decoder
JMPABS is 64-bit absolute direct jump instruction, encoded with a mandatory REX2 prefix. JMPABS is designed to be used in the procedure linkage table (PLT) to replace indirect jumps, because it has better performance. In that case the jump target will be amended at run time. To enable Intel PT to follow the code, a TIP packet is always emitted when JMPABS is traced under Intel PT. Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture Specification for details. Decode JMPABS as an indirect jump, because it has an associated TIP packet the same as an indirect jump and the control flow should follow the TIP packet payload, and not assume it is the same as the on-file object code JMPABS target address. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Nikolay Borisov <nik.borisov@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240502105853.5338-10-adrian.hunter@intel.com
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the reStructuredText markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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