> On 31. Mar 2023, at 16:41, Ni, Ray <ray...@intel.com> wrote: > > Why ELF header overflows into .text section?
That's a good question, isn't it? :) >From what I can see, these binaries don't pass post-processing like GenFw or >such. GCC (and I think thus CLANGDWARF?) gets an extra objcopy step as part of >linking [2], but the arguments are empty [3] and thus should be no-op (I >hope?). I suppose potential candidates are: 1) A bug in the LLD linker used by CLANGDWARF for IA32 and X64. That would be very surprising to me, especially as no other platform reported issues and LLD is well-established. But who knows, generally ELFs will have large alignment values compared to the 64 Bytes used by edk2. 2) A bug in llvm-objcopy used by UniversalPayloadBuild.py [1]. I'm honestly unfamiliar with objcopy variants and their quality/reliability. 3) A bug in the llvm-objcopy or CLANGDWARF tools_def commands on the edk2 side of things. Some may disagree, but I would reduce 3) to either 1) or 2). I think even if the commands malformed and this causes the overflow, I believe LLD or objcopy should issue a warning regardless. As I have no way to reproduce the issue, I cannot really help further, sorry. Best regards, Marvin [1] https://github.com/tianocore/edk2/blob/b08a19eae28e76fb5a296a604c27d06fab29b08a/UefiPayloadPkg/UniversalPayloadBuild.py#L163-L183 [2] https://github.com/tianocore/edk2/blob/b08a19eae28e76fb5a296a604c27d06fab29b08a/BaseTools/Conf/build_rule.template#L298 [3] https://github.com/tianocore/edk2/blob/b08a19eae28e76fb5a296a604c27d06fab29b08a/BaseTools/Conf/tools_def.template#L2895 https://github.com/tianocore/edk2/blob/b08a19eae28e76fb5a296a604c27d06fab29b08a/BaseTools/Conf/tools_def.template#L2931 > >> -----Original Message----- >> From: Patrick Rudolph <patrick.rudo...@9elements.com> >> Sent: Friday, March 17, 2023 10:06 PM >> Cc: devel@edk2.groups.io; Dong, Guo <guo.d...@intel.com>; Guo, Gua >> <gua....@intel.com>; Lu, James <james...@intel.com>; Ni, Ray >> <ray...@intel.com>; mhaeu...@posteo.de; a...@kernel.org >> Subject: [PATCH 2/3] BaseTools/Conf/tools_def: Fix >> CLANGDWARF_IA32_X64 >> >> Drop the "-z max-page-size=0x40" option as it causes the ELF >> header to overflow into the .text section, causing undefined >> behaviour. >> >> With high optimization level it corrupts essential code and >> the binary would crash. It might work with low optimization >> level though. As the default is to use Oz and LTO, it always >> crashes. >> >> Test: >> The ELF generated by >> 'python UefiPayloadPkg/UniversalPayloadBuild.py -a IA32' boots. >> >> Signed-off-by: Patrick Rudolph <patrick.rudo...@9elements.com> >> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4357 >> --- >> BaseTools/Conf/tools_def.template | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/BaseTools/Conf/tools_def.template >> b/BaseTools/Conf/tools_def.template >> index 9b59bd75c3..0c584ab390 100755 >> --- a/BaseTools/Conf/tools_def.template >> +++ b/BaseTools/Conf/tools_def.template >> @@ -2866,7 +2866,7 @@ DEFINE CLANGDWARF_X64_PREFIX = >> ENV(CLANG_BIN) >> >> >> # LLVM/CLANG doesn't support -n link option. So, it can't share the same >> IA32_X64_DLINK_COMMON flag. >> >> # LLVM/CLANG doesn't support common page size. So, it can't share the >> same GccBase.lds script. >> >> -DEFINE CLANGDWARF_IA32_X64_DLINK_COMMON = -nostdlib -Wl,-q,--gc- >> sections -z max-page-size=0x40 >> >> +DEFINE CLANGDWARF_IA32_X64_DLINK_COMMON = -nostdlib -Wl,-q,-- >> gc-sections >> >> DEFINE CLANGDWARF_DLINK2_FLAGS_COMMON = -Wl,-- >> script=$(EDK_TOOLS_PATH)/Scripts/ClangBase.lds >> >> DEFINE CLANGDWARF_IA32_X64_ASLDLINK_FLAGS = >> DEF(CLANGDWARF_IA32_X64_DLINK_COMMON) -Wl,-- >> defsym=PECOFF_HEADER_SIZE=0 >> DEF(CLANGDWARF_DLINK2_FLAGS_COMMON) -Wl,-- >> entry,ReferenceAcpiTable -u ReferenceAcpiTable >> >> DEFINE CLANGDWARF_IA32_X64_DLINK_FLAGS = >> DEF(CLANGDWARF_IA32_X64_DLINK_COMMON) -Wl,-- >> entry,$(IMAGE_ENTRY_POINT) -u $(IMAGE_ENTRY_POINT) -Wl,- >> Map,$(DEST_DIR_DEBUG)/$(BASE_NAME).map,--whole-archive >> >> -- >> 2.39.1 > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#102318): https://edk2.groups.io/g/devel/message/102318 Mute This Topic: https://groups.io/mt/97673649/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
