----- On Jun 25, 2018, at 1:54 PM, Will Deacon [email protected] wrote: [...]
> +#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, > \ > + post_commit_offset, abort_ip) > \ > + " .pushsection __rseq_table, \"aw\"\n" > \ > + " .balign 32\n" > \ > + __rseq_str(label) ":\n" > \ > + " .long " __rseq_str(version) ", " __rseq_str(flags) "\n" > \ > + " .quad " __rseq_str(start_ip) ", " > \ > + __rseq_str(post_commit_offset) ", " > \ > + __rseq_str(abort_ip) "\n" > \ > + " .popsection\n" > + > +#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) > \ > + __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, > \ > + (post_commit_ip - start_ip), abort_ip) > + > +#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) > \ > + RSEQ_INJECT_ASM(1) > \ > + " adrp " RSEQ_ASM_TMP_REG ", " __rseq_str(cs_label) "\n" > \ > + " add " RSEQ_ASM_TMP_REG ", " RSEQ_ASM_TMP_REG > \ > + ", :lo12:" __rseq_str(cs_label) "\n" > \ > + " str " RSEQ_ASM_TMP_REG ", %[" __rseq_str(rseq_cs) "]\n" > \ > + __rseq_str(label) ":\n" > + > +#define RSEQ_ASM_DEFINE_ABORT(label, abort_label) > \ > + " .pushsection __rseq_failure, \"ax\"\n" > \ > + " .long " __rseq_str(RSEQ_SIG) "\n" > \ > + __rseq_str(label) ":\n" > \ > + " b %l[" __rseq_str(abort_label) "]\n" > \ > + " .popsection\n" Thanks Will for porting rseq to arm64 ! I notice you are using the instructions adrp add str to implement RSEQ_ASM_STORE_RSEQ_CS(). Did you compare performance-wise with an approach using a literal pool near the instruction pointer like I did on arm32 ? With that approach, this ends up being simply adr str which provides significantly better performance on my test platform over loading a pointer targeting a separate data section. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
