On 03/06/2017 07:31 AM, Roger Pau Monne wrote:
There seems to be some weird bug in clang 4.0 that prevents xsm_pmu_op from working as expected, and vpmu.o ends up with a reference to __xsm_action_mismatch_detected which makes the build fail:[...] ld -melf_x86_64_fbsd -T xen.lds -N prelink.o \ xen/common/symbols-dummy.o -o xen/.xen-syms.0 prelink.o: In function `xsm_default_action': xen/include/xsm/dummy.h:80: undefined reference to `__xsm_action_mismatch_detected' xen/xen/include/xsm/dummy.h:80: relocation truncated to fit: R_X86_64_PC32 against undefined symbol `__xsm_action_mismatch_detected' ld: xen/xen/.xen-syms.0: hidden symbol `__xsm_action_mismatch_detected' isn't defined Then doing a search in the objects files: # find xen/ -type f -name '*.o' -print0 | xargs -0 bash -c \ 'for filename; do nm "$filename" | \ grep -q __xsm_action_mismatch_detected && echo "$filename"; done' bash xen/arch/x86/prelink.o xen/arch/x86/cpu/vpmu.o xen/arch/x86/cpu/built_in.o xen/arch/x86/built_in.o The current patch is the only way I've found to fix this so far, by simply moving the XSM_PRIV check into the default case in xsm_pmu_op. This also fixes the behavior of do_xenpmu_op, which will now return -EINVAL for unknown XENPMU_* operations, instead of -EPERM when called by a privileged domain. Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Acked-by: Daniel De Graaf <dgde...@tycho.nsa.gov> This also looks like a good patch for backporting. The best alternative I can think of is to disable the mismatch detection in non-DEBUG builds, but I'd rather not do that unless this problem expands more than it has. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
