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Peter Anvin" , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Marco Elver , x86@kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, llvm@lists.linux.dev References: <20260701125151.352632-1-voytikd@gmail.com> Content-Language: en-US From: Ilya Leoshkevich In-Reply-To: <20260701125151.352632-1-voytikd@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODE4MDEzMyBTYWx0ZWRfXykfSQBA7Lksw W1dXri9x8UBF8W1c6VbZZlrXsRErJTWfLUbOX41paanvjh6j6ymjP4Dh4mafxLiOvxJXrBQDu0J Y3kLSLZN4F9X6zeuMRGKBMzfcfkZsjeiJT7Mg1mvrNmreNc4BMY3gG73ReSV243MT+GwKvZaonc wUBE5MqAxEeSE4ZpOHTVmLj+R1m+ZNZXJClb+qAbfyvTvNiNfUxeTBzNBGcRxmuMytAWGIMFDtH Uf29UesSk3Izv9VLmMyNmzHRw7gYAaq8XpwTIfjeRwRHoPwflOwMTMIXinuEuOvinJFp7bm5ImB CGbMb9E/+V/eeFnHidZ2loILu4d1gQ1UsroMd0ggsuHyZZ0JysSLsMPmYjqpbfjRndlk1Fz5TWk X/MfT5KOniGhAp6tEvvM5Xywzrjhdf/1SNIZsiC2GyiLAz5GVXRh24hN/mPAg1z/b26XtXmqV+g jNfGZ38mISJEPtqIZvg== X-Authority-Analysis: v=2.4 cv=DY8nbPtW c=1 sm=1 tr=0 ts=6a849edf cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=fGO4tVQLAAAA:8 a=VnNF1IyMAAAA:8 a=IzFO8XHbKeul4SU-JC8A:9 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: Rgl4_PeBW0ljUeOiw7MXuCe5_aW-h4AJ X-Proofpoint-GUID: 7ss18Xr76sCLSOddYB1MDNBU4H7p8GEM X-Proofpoint-Spam-Info: AW1haW4tMjYwODE4MDEzMyBTYWx0ZWRfX8EIlgqIcWRdq 4H/LwsfTGoLEQN3ZeKbxbkFSYWgLA+Gqt6/YU87myd5oX0+AL8FXpRbSsaF8sIMv1kOwO3BEr97 rcEbvVyMqIFXltMzvCalMwNdHMnF0MM= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-18_03,2026-08-18_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 clxscore=1011 spamscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 lowpriorityscore=0 phishscore=0 suspectscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608180133 On 7/1/26 14:51, Dmitry Voytik wrote: > This patch fixes broken builds with defconfig + CONFIG_KMSAN + > CONFIG_DEBUG_INFO_*. > > To reproduce the issue before the fix: > make mrproper > make LLVM=1 defconfig > ./scripts/config -e CONFIG_KMSAN \ > -e CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > make LLVM=1 olddefconfig > make LLVM=1 -j(nproc) vmlinux > ... > LD vmlinux.o > vmlinux.o: warning: objtool: folio_zero_user+0x801: undefined stack state > vmlinux.o: error: objtool: folio_zero_user+0x801: unknown CFA base reg -1 > make[2]: *** [scripts/Makefile.vmlinux_o:76: vmlinux.o] Error 255 > > objtool in verbose mode shows how the frame pointer is omitted: > make LLVM=1 OBJTOOL_VERBOSE=1 -j(nproc) vmlinux > ... > b15a2c: folio_zero_user+0x7fc xor %eax,%eax > b15a2e: folio_zero_user+0x7fe mov %rcx,%rsp > b15a31: folio_zero_user+0x801 mov %r14,%rdi > b15a34: folio_zero_user+0x804 mov %rbx,%rcx > b15a37: folio_zero_user+0x807 call 0xb15a3c <__clear_pages_unrol > > After the fix, the frame pointer is back: > b15a37: 31 c0 xor %eax,%eax > b15a39: 48 89 ec mov %rbp,%rsp > b15a3c: 4c 89 f7 mov %r14,%rdi > b15a3f: 48 89 d9 mov %rbx,%rcx > b15a42: e8 00 00 00 00 call b15a47 > > It seems the issue was introduced by > commit 54a6b89a3db2 ("x86/mm: simplify clear_page_*") > > The actual fix is to revert the change how ASM_CALL_CONSTRAINT is > positioned. > Additionally, reintroduce asm_inline to prevent potential compiler > rejection of inlining. > > Link: https://lore.kernel.org/CAAX90H2_RPnZL_dFYN7cQF6yt-wAweKKSx2=6e2aZ0kv+Pm+NQ@mail.gmail.com > Signed-off-by: Dmitry Voytik > --- > arch/x86/include/asm/page_64.h | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) FWIW I just bumped into this build issue; this patch helped and the resulting kernel booted. Config: https://pastebin.com/B6GedVDL Tested-by: Ilya Leoshkevich