Am 8. März 2023 17:18:32 MEZ schrieb Tom Rini <tr...@konsulko.com>: >On Wed, Mar 08, 2023 at 05:12:26AM +0100, Heinrich Schuchardt wrote: >> Hello Ilias, hello Tom, >> >> Tom tried to run qemu_arm_defconfig with CONFIG_LTO=y in gitlab. This >> failed as shown in protocol >> https://source.denx.de/u-boot/u-boot/-/jobs/589913/raw >> >> Executing 'HII database protocols' >> test_hii_database_new_package_list: >> data abort >> pc : [<7ff39b98>] lr : [<7ff87328>] >> reloc pc : [<00000b98>] lr : [<0004e328>] >> sp : 7edf8cc0 ip : 0000000c fp : 7ffe60ec >> r10: 00000000 r9 : 7eef8eb0 r8 : 7ffe0d02 >> r7 : 00000000 r6 : 7ef0f8c8 r5 : 7ffe0cf0 r4 : 7ffe0cb4 >> r3 : 7ffe0cef r2 : 00000000 r1 : ffffffff r0 : 00000000 >> Flags: nzcv IRQs off FIQs off Mode SVC_32 >> Code: e2403002 e3a00000 e1500001 012fff1e (e1f320b2) >> UEFI image [0x00000000:0xffffffff] '/\selftest' >> Resetting CPU .. >> >> Debugging shows: >> >> efi_hii_sibt_string_ucs2_block_next() calls u16_strnlen() for an >> unaligned u16 string. Here "ldrh r2, [r3, #2]!" is executed for >> unaligned r3. This should be allowable for SCTLR.A = 0. >> >> When the crash occurs SCRLR has value 0xc5187f. SCTLR.A is bit 1 with >> value 1. >> >> The implementation of allow_unaligned() in >> arch/arm/cpu/armv7 /sctlr.S should have set the flag to 0. >> arch/arm/cpu/armv7/sctlr.S is compiled (as demonstrated by adding #error >> to the code). >> >> If I remove the weak implementation of allow_unaligned() in >> lib/efi_loader/efi_setup.c, the error does not occur. >> >> Shouldn't building with LTO ignore the weak implementation? >> >> If I add a printf() statement to the weak implemenation, the printf() >> command is not executed but >> >> SCTLR 0xc5187d, SCTLR.A=0 >> >> The test passes as unaligned access is allowable. >> >> I was building inside the Docker image with the GCC downloaded by >> buildman (gcc-12.2.0-nolibc/arm-linux-gnueabi). >> >> To me this looks like a compiler issue. > >Interesting, yes. It seems like it shouldn't be too hard to come up with >a condensed example where the assembly function isn't used but instead >the weak C function is. > >And as a work-around, re-doing the code so that path_to_uefi() just >checks for ARM && !ARM64 before calling allow_unaligned() and not doing >the weak function trick should also be fine. > We have more places in our code using weak functions. There many cases not covered by CI. Just looking at EFI may not be adequate. Best regards Heinrich
