Hi Arnaldo, On Thu, Jun 06, 2019 at 11:44:12AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, Jun 06, 2019 at 10:12:31PM +0800, Leo Yan escreveu: > > Hi Arnaldo, > > > > On Thu, Jun 06, 2019 at 10:38:38AM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Thu, Jun 06, 2019 at 05:48:44PM +0800, Leo Yan escreveu: > > > > This patch adds support for arm64 raw syscall numbers so that we can use > > > > it on arm64 platform. > > > > > > > > After applied this patch, we need to specify macro -D__aarch64__ or > > > > -D__x86_64__ in compilation option so Clang can use the corresponding > > > > syscall numbers for arm64 or x86_64 respectively, other architectures > > > > will report failure when compilation. > > > > > > So, please check what I have in my perf/core branch, I've completely > > > removed arch specific stuff from augmented_raw_syscalls.c. > > > > > > What is done now is use a map to specify what to copy, that same map > > > that is used to state which syscalls should be traced. > > > > > > It uses that tools/perf/arch/arm64/entry/syscalls/mksyscalltbl to figure > > > out the mapping of syscall names to ids, just like is done for x86_64 > > > and other arches, falling back to audit-libs when that syscalltbl thing > > > is not present. > > > > Actually I have noticed mksyscalltbl has been enabled for arm64, and > > had to say your approach is much better :) > > > > Thanks for the info and I will try your patch at my side. > > That is excellent news! I'm eager to hear from you if this perf+BPF > integration experiment works for arm64. I tested with the lastest perf/core branch which contains the patch: 'perf augmented_raw_syscalls: Tell which args are filenames and how many bytes to copy' and got the error as below: # perf trace -e string -e /mnt/linux-kernel/linux-cs-dev/tools/perf/examples/bpf/augmented_raw_syscalls.c Error: Invalid syscall access, chmod, chown, creat, futimesat, lchown, link, lstat, mkdir, mknod, newfstatat, open, readlink, rename, rmdir, stat, statfs, symlink, truncate, unlink Hint: try 'perf list syscalls:sys_enter_*' Hint: and: 'man syscalls' So seems mksyscalltbl has not included completely for syscalls, I use below command to generate syscalltbl_arm64[] array and it don't include related entries for access, chmod, chown, etc ... You could refer the generated syscalltbl_arm64 in: http://paste.ubuntu.com/p/8Bj7Jkm2mP/ > I'm now trying to get past the verifier when checking if more than one > syscall arg is a filename, i.e. things like the rename* family, that > take two filenames. > > An exercise in loop unrolling, providing the right hints to the > verifier, making sure clang don't trash those via explicit barriers, and > a lot of patience, limitless fun! ;-) Cool! Please feel free let me know if need me to do testing for this. Thanks, Leo Yan
