From 9e4d116faff4545a7f21c2b01008e94d68e6db58 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Roger=20Pau=20Monn=C3=A9?= Date: Tue, 14 Mar 2017 18:19:29 +0100 Subject: [PATCH] build/clang: fix XSM dummy policy when using clang 4.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Acked-by: Daniel De Graaf --- xen/include/xsm/dummy.h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h index 4b27ae72de..ff730391d5 100644 --- a/xen/include/xsm/dummy.h +++ b/xen/include/xsm/dummy.h @@ -682,18 +682,13 @@ static XSM_INLINE int xsm_pmu_op (XSM_DEFAULT_ARG struct domain *d, unsigned int XSM_ASSERT_ACTION(XSM_OTHER); switch ( op ) { - case XENPMU_mode_set: - case XENPMU_mode_get: - case XENPMU_feature_set: - case XENPMU_feature_get: - return xsm_default_action(XSM_PRIV, d, current->domain); case XENPMU_init: case XENPMU_finish: case XENPMU_lvtpc_set: case XENPMU_flush: return xsm_default_action(XSM_HOOK, d, current->domain); default: - return -EPERM; + return xsm_default_action(XSM_PRIV, d, current->domain); } } -- 2.30.2