Hi Josh and Peter,
I've updated my randconfig test setup to use gcc-13 and clang-16, and
have sent fixes for all normal WERROR=y build warnings, but there are a
lot of objtool warnings that remain. I've reported some of them in
the past, some others are new. It would be nice to at least reduce
the number of warnings either through code changes or workarounds
in objtool for any false positives.
Out of 1500 builds, about a third had any warnings, this is the full
list sorted by frequency. Let me know if there are any that you haven't
seen before, I can provide the corresponding object and config files
for reproducing.
Arnd
8<---
205 mm/kasan/shadow.o: warning: objtool: __asan_memset+0x2e: call to __memset() with UACCESS enabled
205 mm/kasan/shadow.o: warning: objtool: __asan_memmove+0x48: call to __memmove() with UACCESS enabled
205 mm/kasan/shadow.o: warning: objtool: __asan_memcpy+0x48: call to __memcpy() with UACCESS enabled
80 vmlinux.o: warning: objtool: ibt_selftest+0x11: sibling call from callable instruction with modified stack frame
49 vmlinux.o: warning: objtool: lkdtm_UNSET_SMEP+0x100: relocation to !ENDBR: native_write_cr4+0x4
29 mm/kasan/generic.o: warning: objtool: kasan_check_range+0x1e: call to addr_has_metadata() with UACCESS enabled
29 mm/kasan/generic.o: warning: objtool: __asan_load2+0x11: call to addr_has_metadata() with UACCESS enabled
29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_out+0x15e: return with modified stack frame
29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_out+0x11d: stack state mismatch: cfa1=5+16 cfa2=4+8
29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_in+0x150: return with modified stack frame
29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_in+0x13d: stack state mismatch: cfa1=5+16 cfa2=4+8
29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_out+0xe2: return with modified stack frame
29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_out+0xd1: stack state mismatch: cfa1=5+16 cfa2=4+8
29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_in+0xea: return with modified stack frame
29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_in+0xcc: stack state mismatch: cfa1=5+16 cfa2=4+8
28 mm/kasan/generic.o: warning: objtool: __asan_store16+0x11: call to addr_has_metadata() with UACCESS enabled
28 mm/kasan/generic.o: warning: objtool: __asan_load16+0x11: call to addr_has_metadata() with UACCESS enabled
23 fs/reiserfs/do_balan.o: warning: objtool: balance_leaf+0x100ac: stack state mismatch: cfa1=4+464 cfa2=4+456
22 mm/kasan/generic.o: warning: objtool: __asan_load4+0x11: call to addr_has_metadata() with UACCESS enabled
21 mm/kasan/generic.o: warning: objtool: __asan_store4+0x11: call to addr_has_metadata() with UACCESS enabled
21 mm/kasan/generic.o: warning: objtool: __asan_store1+0x11: call to addr_has_metadata() with UACCESS enabled
21 mm/kasan/generic.o: warning: objtool: __asan_load8+0x11: call to addr_has_metadata() with UACCESS enabled
21 mm/kasan/generic.o: warning: objtool: __asan_load1+0x11: call to addr_has_metadata() with UACCESS enabled
18 fs/reiserfs/reiserfs.o: warning: objtool: balance_internal+0x1238: stack state mismatch: cfa1=4+248 cfa2=4+256
18 fs/reiserfs/ibalance.o: warning: objtool: balance_internal+0x10a2: stack state mismatch: cfa1=4+232 cfa2=4+256
17 arch/x86/coco/tdx/tdcall.o: warning: objtool: __tdx_hypercall+0xb0: return with modified stack frame
15 vmlinux.o: warning: objtool: ftrace_likely_update+0xd2: call to __stack_chk_fail() with UACCESS enabled
15 kernel/trace/trace_branch.o: warning: objtool: ftrace_likely_update+0x201: call to __stack_chk_fail() with UACCESS enabled
14 mm/kasan/generic.o: warning: objtool: __asan_store2+0x11: call to addr_has_metadata() with UACCESS enabled
14 arch/x86/kvm/kvm.o: warning: objtool: .text+0x0: unreachable instruction
13 mm/kasan/generic.o: warning: objtool: __asan_store8+0x11: call to addr_has_metadata() with UACCESS enabled
11 vmlinux.o: warning: objtool: replace_key+0x1b2: stack state mismatch: cfa1=4+72 cfa2=4+88
8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x49: relocation to !ENDBR: kgdb_ll_trap+0x6a
8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x28: relocation to !ENDBR: kgdb_arch_late+0x193
8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: kexec_mark_range+0x13
8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: kexec_mark_crashkres+0x53
8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: .text+0x4b314
8 drivers/media/platform/qcom/camss/qcom-camss.o: warning: objtool: csiphy_lanes_enable() falls through to next function __cfi_csiphy_hw_version_read()
8 drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.o: warning: objtool: csiphy_lanes_enable() falls through to next function __cfi_csiphy_get_lane_mask()
7 vmlinux.o: warning: objtool: internal_move_pointers_items+0x3fa: stack state mismatch: cfa1=4+144 cfa2=4+136
7 fs/jffs2/jffs2.o: warning: objtool: jffs2_erase_pending_blocks() falls through to next function jffs2_free_jeb_node_refs()
7 fs/jffs2/erase.o: warning: objtool: jffs2_erase_pending_blocks() falls through to next function __cfi_jffs2_free_jeb_node_refs()
7 drivers/hwmon/pmbus/adm1275.o: warning: objtool: adm1275_probe+0x574: unreachable instruction
5 vmlinux.o: warning: objtool: exynos3250_cmu_isp_probe+0x17: unreachable instruction
5 arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x2c0: unreachable instruction
5 arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_vcpu_run+0x141: BP used as a scratch register
5 arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_sev_es_vcpu_run+0x36: BP used as a scratch register
4 vmlinux.o: warning: objtool: resume_play_dead+0xe: unreachable instruction
4 vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction
4 vmlinux.o: warning: objtool: do_idle+0x15e: unreachable instruction
4 drivers/media/i2c/m5mols/m5mols_core.o: warning: objtool: m5mols_set_fmt() falls through to next function __cfi_m5mols_get_frame_desc()
3 vmlinux.o: warning: objtool: nmi_panic+0x2d: unreachable instruction
3 vmlinux.o: warning: objtool: mptscsih_abort+0x319: unreachable instruction
3 vmlinux.o: warning: objtool: internal_delete_pointers_items+0x392: stack state mismatch: cfa1=4+136 cfa2=4+144
3 vmlinux.o: warning: objtool: emulate_vsyscall+0x1ff: unreachable instruction
3 vmlinux.o: warning: objtool: do_arch_prctl_64+0x1ac: unreachable instruction
3 fs/xfs/libxfs/xfs_da_btree.o: warning: objtool: xfs_da_grow_inode_int+0x397: stack state mismatch: reg1[12]=-2-48 reg2[12]=-1+0
3 drivers/spi/spi-amd.o: warning: objtool: amd_spi_master_transfer() falls through to next function __cfi_amd_spi_max_transfer_size()
3 drivers/pwm/pwm-mediatek.o: warning: objtool: .text: unexpected end of section
3 drivers/gpu/drm/i915/gt/intel_timeline.o: warning: objtool: live_hwsp_read+0x318: stack state mismatch: cfa1=4+240 cfa2=5+48
3 arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0xba7: unreachable instruction
2 vmlinux.o: warning: objtool: xenpv_exc_double_fault+0x9: unreachable instruction
2 vmlinux.o: warning: objtool: pwm_mediatek_apply() falls through to next function mtk_disp_pwm_probe()
2 vmlinux.o: warning: objtool: force_ibs_eilvt_setup+0xad: unreachable instruction
2 vmlinux.o: warning: objtool: exynos7885_cmu_probe+0x1b: unreachable instruction
2 vmlinux.o: warning: objtool: do_one_initcall+0x1f6: unreachable instruction
2 mm/kmsan/report.o: warning: objtool: kmsan_report+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_warning+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_poison_alloca+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_n+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_8+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_4+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_2+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_1+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_n+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_8+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_4+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_2+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_1+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_instrument_asm_store+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_get_context_state+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/instrumentation.o: warning: objtool: __msan_chain_origin+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/hooks.o: warning: objtool: kmsan_unpoison_memory+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/hooks.o: warning: objtool: kmsan_unpoison_entry_regs+0x0: call to __fentry__() with UACCESS enabled
2 mm/kmsan/hooks.o: warning: objtool: kmsan_copy_to_user+0x0: call to __fentry__() with UACCESS enabled
2 fs/reiserfs/lbalance.o: warning: objtool: leaf_move_items+0x7ab: stack state mismatch: cfa1=4+160 cfa2=4+152
2 drivers/video/fbdev/omap2/omapfb/dss/omapdss.o: warning: objtool: hdmi_power_on_full.isra.0+0x5e: unreachable instruction
2 drivers/net/wwan/iosm/iosm.o: warning: objtool: ipc_imem_run_state_worker() falls through to next function ipc_imem_startup_timer_cb()
2 drivers/iio/imu/bmi160/bmi160_core.o: warning: objtool: bmi160_setup_irq() falls through to next function bmi160_data_rdy_trigger_set_state()
1 vmlinux.o: warning: objtool: trace_initcall_finish+0xee: unreachable instruction
1 vmlinux.o: warning: objtool: native_sched_clock_from_tsc+0x60: unreachable instruction
1 vmlinux.o: warning: objtool: lpass_cdc_dma_daiops_trigger() falls through to next function lpass_hdmi_daiops_hw_params()
1 drivers/crypto/keembay/keembay-ocs-hcu.o: warning: objtool: ocs_hcu_hmac+0x153: stack state mismatch: cfa1=4+136 cfa2=5+48
1 arch/x86/kvm/kvm-amd.o: warning: objtool: .altinstr_replacement+0x108: call without frame pointer save/setup
On Tue, Feb 07, 2023 at 11:25:27AM +0100, Arnd Bergmann wrote:
> Hi Josh and Peter,
>
> I've updated my randconfig test setup to use gcc-13 and clang-16, and
> have sent fixes for all normal WERROR=y build warnings, but there are a
> lot of objtool warnings that remain. I've reported some of them in
> the past, some others are new. It would be nice to at least reduce
> the number of warnings either through code changes or workarounds
> in objtool for any false positives.
>
> Out of 1500 builds, about a third had any warnings, this is the full
> list sorted by frequency. Let me know if there are any that you haven't
> seen before, I can provide the corresponding object and config files
> for reproducing.
>
> Arnd
>
> 8<---
> 205 mm/kasan/shadow.o: warning: objtool: __asan_memset+0x2e: call to __memset() with UACCESS enabled
> 205 mm/kasan/shadow.o: warning: objtool: __asan_memmove+0x48: call to __memmove() with UACCESS enabled
> 205 mm/kasan/shadow.o: warning: objtool: __asan_memcpy+0x48: call to __memcpy() with UACCESS enabled
Patch pending here:
https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/core-robot&id=79cdfdacd5b8d1ac77e24ccbc178bba0294d0d78

> 80 vmlinux.o: warning: objtool: ibt_selftest+0x11: sibling call from callable instruction with modified stack frame
Can you provide details on how to reproduce this?
> 49 vmlinux.o: warning: objtool: lkdtm_UNSET_SMEP+0x100: relocation to !ENDBR: native_write_cr4+0x4
That one was on purpose I think.
> 29 mm/kasan/generic.o: warning: objtool: kasan_check_range+0x1e: call to addr_has_metadata() with UACCESS enabled
> 29 mm/kasan/generic.o: warning: objtool: __asan_load2+0x11: call to addr_has_metadata() with UACCESS enabled
I'm thinking addr_has_metadata() needs the __always_inline treatment, it
seems to be present a lot.
> 28 mm/kasan/generic.o: warning: objtool: __asan_store16+0x11: call to addr_has_metadata() with UACCESS enabled
> 28 mm/kasan/generic.o: warning: objtool: __asan_load16+0x11: call to addr_has_metadata() with UACCESS enabled
> 22 mm/kasan/generic.o: warning: objtool: __asan_load4+0x11: call to addr_has_metadata() with UACCESS enabled
> 21 mm/kasan/generic.o: warning: objtool: __asan_store4+0x11: call to addr_has_metadata() with UACCESS enabled
> 21 mm/kasan/generic.o: warning: objtool: __asan_store1+0x11: call to addr_has_metadata() with UACCESS enabled
> 21 mm/kasan/generic.o: warning: objtool: __asan_load8+0x11: call to addr_has_metadata() with UACCESS enabled
> 21 mm/kasan/generic.o: warning: objtool: __asan_load1+0x11: call to addr_has_metadata() with UACCESS enabled
> 29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_out+0x15e: return with modified stack frame
> 29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_out+0x11d: stack state mismatch: cfa1=5+16 cfa2=4+8
> 29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_in+0x150: return with modified stack frame
> 29 drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_port_hb_in+0x13d: stack state mismatch: cfa1=5+16 cfa2=4+8
> 29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_out+0xe2: return with modified stack frame
> 29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_out+0xd1: stack state mismatch: cfa1=5+16 cfa2=4+8
> 29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_in+0xea: return with modified stack frame
> 29 drivers/gpu/drm/vmwgfx/vmwgfx.o: warning: objtool: vmw_port_hb_in+0xcc: stack state mismatch: cfa1=5+16 cfa2=4+8
Repro details?
> 18 fs/reiserfs/reiserfs.o: warning: objtool: balance_internal+0x1238: stack state mismatch: cfa1=4+248 cfa2=4+256
> 18 fs/reiserfs/ibalance.o: warning: objtool: balance_internal+0x10a2: stack state mismatch: cfa1=4+232 cfa2=4+256
> 17 arch/x86/coco/tdx/tdcall.o: warning: objtool: __tdx_hypercall+0xb0: return with modified stack frame
Fix on list somewhere..
> 15 vmlinux.o: warning: objtool: ftrace_likely_update+0xd2: call to __stack_chk_fail() with UACCESS enabled
> 15 kernel/trace/trace_branch.o: warning: objtool: ftrace_likely_update+0x201: call to __stack_chk_fail() with UACCESS enabled
-EWONTFIX, TRACE_BRANCH_PROFILING is fundamentally incompatible with
lots of things.
> 14 mm/kasan/generic.o: warning: objtool: __asan_store2+0x11: call to addr_has_metadata() with UACCESS enabled
> 13 mm/kasan/generic.o: warning: objtool: __asan_store8+0x11: call to addr_has_metadata() with UACCESS enabled
> 14 arch/x86/kvm/kvm.o: warning: objtool: .text+0x0: unreachable instruction
details?
> 11 vmlinux.o: warning: objtool: replace_key+0x1b2: stack state mismatch: cfa1=4+72 cfa2=4+88
> 8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x49: relocation to !ENDBR: kgdb_ll_trap+0x6a
> 8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x28: relocation to !ENDBR: kgdb_arch_late+0x193
> 8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: kexec_mark_range+0x13
> 8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: kexec_mark_crashkres+0x53
> 8 vmlinux.o: warning: objtool: set_ftrace_ops_ro+0x23: relocation to !ENDBR: .text+0x4b314
> 8 drivers/media/platform/qcom/camss/qcom-camss.o: warning: objtool: csiphy_lanes_enable() falls through to next function __cfi_csiphy_hw_version_read()
> 8 drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.o: warning: objtool: csiphy_lanes_enable() falls through to next function __cfi_csiphy_get_lane_mask()
> 7 vmlinux.o: warning: objtool: internal_move_pointers_items+0x3fa: stack state mismatch: cfa1=4+144 cfa2=4+136
> 7 fs/jffs2/jffs2.o: warning: objtool: jffs2_erase_pending_blocks() falls through to next function jffs2_free_jeb_node_refs()
> 7 fs/jffs2/erase.o: warning: objtool: jffs2_erase_pending_blocks() falls through to next function __cfi_jffs2_free_jeb_node_refs()
> 7 drivers/hwmon/pmbus/adm1275.o: warning: objtool: adm1275_probe+0x574: unreachable instruction
> 5 vmlinux.o: warning: objtool: exynos3250_cmu_isp_probe+0x17: unreachable instruction
> 5 arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x2c0: unreachable instruction
> 5 arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_vcpu_run+0x141: BP used as a scratch register
> 5 arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_sev_es_vcpu_run+0x36: BP used as a scratch register
> 4 vmlinux.o: warning: objtool: resume_play_dead+0xe: unreachable instruction
> 4 vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction
> 4 vmlinux.o: warning: objtool: do_idle+0x15e: unreachable instruction
> 4 drivers/media/i2c/m5mols/m5mols_core.o: warning: objtool: m5mols_set_fmt() falls through to next function __cfi_m5mols_get_frame_desc()
> 3 vmlinux.o: warning: objtool: nmi_panic+0x2d: unreachable instruction
> 3 vmlinux.o: warning: objtool: mptscsih_abort+0x319: unreachable instruction
> 3 vmlinux.o: warning: objtool: internal_delete_pointers_items+0x392: stack state mismatch: cfa1=4+136 cfa2=4+144
> 3 vmlinux.o: warning: objtool: emulate_vsyscall+0x1ff: unreachable instruction
> 3 vmlinux.o: warning: objtool: do_arch_prctl_64+0x1ac: unreachable instruction
> 3 fs/xfs/libxfs/xfs_da_btree.o: warning: objtool: xfs_da_grow_inode_int+0x397: stack state mismatch: reg1[12]=-2-48 reg2[12]=-1+0
> 3 drivers/spi/spi-amd.o: warning: objtool: amd_spi_master_transfer() falls through to next function __cfi_amd_spi_max_transfer_size()
> 3 drivers/pwm/pwm-mediatek.o: warning: objtool: .text: unexpected end of section
> 3 drivers/gpu/drm/i915/gt/intel_timeline.o: warning: objtool: live_hwsp_read+0x318: stack state mismatch: cfa1=4+240 cfa2=5+48
> 3 arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0xba7: unreachable instruction
> 2 vmlinux.o: warning: objtool: xenpv_exc_double_fault+0x9: unreachable instruction
> 2 vmlinux.o: warning: objtool: pwm_mediatek_apply() falls through to next function mtk_disp_pwm_probe()
> 2 vmlinux.o: warning: objtool: force_ibs_eilvt_setup+0xad: unreachable instruction
> 2 vmlinux.o: warning: objtool: exynos7885_cmu_probe+0x1b: unreachable instruction
> 2 vmlinux.o: warning: objtool: do_one_initcall+0x1f6: unreachable instruction
> 2 mm/kmsan/report.o: warning: objtool: kmsan_report+0x0: call to __fentry__() with UACCESS enabled
mm/kasan/Makefil:CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE)
How?!?!

> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_warning+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_poison_alloca+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_n+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_8+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_4+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_2+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_store_1+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_n+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_8+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_4+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_2+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_metadata_ptr_for_load_1+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_instrument_asm_store+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_get_context_state+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/instrumentation.o: warning: objtool: __msan_chain_origin+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/hooks.o: warning: objtool: kmsan_unpoison_memory+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/hooks.o: warning: objtool: kmsan_unpoison_entry_regs+0x0: call to __fentry__() with UACCESS enabled
> 2 mm/kmsan/hooks.o: warning: objtool: kmsan_copy_to_user+0x0: call to __fentry__() with UACCESS enabled
Something seems to be going badly wrong there... notrace is being lost.
On Tue, Feb 07, 2023 at 05:16:58PM +0100, Peter Zijlstra wrote:
> On Tue, Feb 07, 2023 at 11:25:27AM +0100, Arnd Bergmann wrote:
> > Hi Josh and Peter,
> >
> > I've updated my randconfig test setup to use gcc-13 and clang-16, and
> > have sent fixes for all normal WERROR=y build warnings, but there are a
> > lot of objtool warnings that remain. I've reported some of them in
> > the past, some others are new. It would be nice to at least reduce
> > the number of warnings either through code changes or workarounds
> > in objtool for any false positives.
> >
> > Out of 1500 builds, about a third had any warnings, this is the full
> > list sorted by frequency. Let me know if there are any that you haven't
> > seen before, I can provide the corresponding object and config files
> > for reproducing.
> >
> > Arnd
> >
> > 8<---
> > 205 mm/kasan/shadow.o: warning: objtool: __asan_memset+0x2e: call to __memset() with UACCESS enabled
> > 205 mm/kasan/shadow.o: warning: objtool: __asan_memmove+0x48: call to __memmove() with UACCESS enabled
> > 205 mm/kasan/shadow.o: warning: objtool: __asan_memcpy+0x48: call to __memcpy() with UACCESS enabled
>
> Patch pending here:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/core-robot&id=79cdfdacd5b8d1ac77e24ccbc178bba0294d0d78
> 
>
> > 80 vmlinux.o: warning: objtool: ibt_selftest+0x11: sibling call from callable instruction with modified stack frame
>
> Can you provide details on how to reproduce this?
Arnd, thanks for rounding these up and posting them.
I agree we need to get these all cleaned up, but before we go too far
down the rabbit hole, is there some better way to track these?
Not that I would suggest using an external tracker, but maybe at least
put each set of related warnings (e.g., those having the same frequency)
in its own subthread with the config/compiler info included.
--
Josh
On Tue, Feb 7, 2023 at 9:42 AM Josh Poimboeuf <[email protected]> wrote:
>
> On Tue, Feb 07, 2023 at 05:16:58PM +0100, Peter Zijlstra wrote:
> > On Tue, Feb 07, 2023 at 11:25:27AM +0100, Arnd Bergmann wrote:
> > > Hi Josh and Peter,
> > >
> > > I've updated my randconfig test setup to use gcc-13 and clang-16, and
> > > have sent fixes for all normal WERROR=y build warnings, but there are a
> > > lot of objtool warnings that remain. I've reported some of them in
> > > the past, some others are new. It would be nice to at least reduce
> > > the number of warnings either through code changes or workarounds
> > > in objtool for any false positives.
> > >
> > > Out of 1500 builds, about a third had any warnings, this is the full
> > > list sorted by frequency. Let me know if there are any that you haven't
> > > seen before, I can provide the corresponding object and config files
> > > for reproducing.
> > >
> > > Arnd
> > >
> > > 8<---
> > > 205 mm/kasan/shadow.o: warning: objtool: __asan_memset+0x2e: call to __memset() with UACCESS enabled
> > > 205 mm/kasan/shadow.o: warning: objtool: __asan_memmove+0x48: call to __memmove() with UACCESS enabled
> > > 205 mm/kasan/shadow.o: warning: objtool: __asan_memcpy+0x48: call to __memcpy() with UACCESS enabled
> >
> > Patch pending here:
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/core-robot&id=79cdfdacd5b8d1ac77e24ccbc178bba0294d0d78
> > 
> >
> > > 80 vmlinux.o: warning: objtool: ibt_selftest+0x11: sibling call from callable instruction with modified stack frame
> >
> > Can you provide details on how to reproduce this?
>
> Arnd, thanks for rounding these up and posting them.
>
> I agree we need to get these all cleaned up, but before we go too far
> down the rabbit hole, is there some better way to track these?
>
> Not that I would suggest using an external tracker, but maybe at least
> put each set of related warnings (e.g., those having the same frequency)
> in its own subthread with the config/compiler info included.
If any are specific to clang, please use
https://github.com/ClangBuiltLinux/linux/issues
We have a tag for issues flagged by objtool
https://github.com/ClangBuiltLinux/linux/issues?q=is%3Aopen+is%3Aissue+label%3A%22%5BTOOL%5D+objtool%22
>
> --
> Josh
>
--
Thanks,
~Nick Desaulniers