Messages in this thread | | | From | Nick Desaulniers <> | Date | Wed, 9 Mar 2022 16:30:28 -0800 | Subject | Re: [PATCH v4 00/45] x86: Kernel IBT |
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On Tue, Mar 8, 2022 at 2:32 PM Peter Zijlstra <peterz@infradead.org> wrote: > > On Tue, Mar 08, 2022 at 11:01:04PM +0100, Peter Zijlstra wrote: > > On Tue, Mar 08, 2022 at 12:00:52PM -0800, Alexei Starovoitov wrote: > > > On Tue, Mar 08, 2022 at 04:30:11PM +0100, Peter Zijlstra wrote: > > > > Hopefully last posting... > > > > > > > > Since last time: > > > > - verified clang-14-rc2 works > > > > git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/wip.ibt
I observed the following error when building with CONFIG_LTO_CLANG_FULL=y enabled:
ld.lld: error: ld-temp.o <inline asm>:7:2: symbol 'ibt_selftest_ip' is already defined ibt_selftest_ip: ^
Seems to come from commit a802350ba65a ("x86/ibt: Add IBT feature, MSR and #CP handling")
Commenting out the label in the inline asm, I then observed: vmlinux.o: warning: objtool: identify_cpu()+0x6d0: sibling call from callable instruction with modified stack frame vmlinux.o: warning: objtool: identify_cpu()+0x6e0: stack state mismatch: cfa1=4+64 cfa2=4+8 These seemed to disappear when I kept CONFIG_LTO_CLANG_FULL=y but then disabled CONFIG_X86_KERNEL_IBT. (perhaps due to the way I hacked out the ibt_selftest_ip label).
Otherwise defconfig and CONFIG_LTO_CLANG_THIN=y both built and booted in a vm WITHOUT IBT support.
Any idea what's the status of IBT emulation in QEMU, and if it exists, what's the necessary `-cpu` flag to enable it? -- Thanks, ~Nick Desaulniers
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