On 26/01/2025 20:04, Cong Wang wrote: > On Sat, Jan 25, 2025 at 8:55 PM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote: >> >> Hi Alan, >> >> On Tue, Dec 17, 2024 at 2:36 AM Alan Maguire <alan.maguire@xxxxxxxxxx> wrote: >>> >>> We use the DWARF location information to match a variable with its >>> associated ELF section. In the case of per-CPU variables their >>> ELF section address range starts at 0, so any 0 address variables will >>> appear to belong in that ELF section. However, for "discard" sections >>> DWARF encodes the associated variables with address location 0 so >>> we need to double-check that address 0 variables really are in the >>> associated section by checking the ELF symbol table. >>> >>> This resolves an issue exposed by CONFIG_DEBUG_FORCE_WEAK_PER_CPU=y >>> kernel builds where __pcpu_* dummary variables in a .discard section >>> get misclassified as belonging in the per-CPU variable section since >>> they specify location address 0. >> >> It is _not_ your patch's fault, but I got this segfault which prevents me from >> testing this patch. (It also happens after reverting your patch.) > > Never mind, I managed to workaround this issue by a clean build. > > And I tested your patch, it works for me with CONFIG_DEBUG_FORCE_WEAK_PER_CPU=y. > > Tested-by: Cong Wang <cong.wang@xxxxxxxxxxxxx> > > Thanks a lot! Thanks for verifying the fix! You didn't happen to get a coredump or backtrace for the earlier segmentation fault by any chance? Just want to make sure there aren't other issues lurking here. Thanks again! Alan
