3 Commits

Author	SHA1	Message	Date
Fangrui Song	c49f83b6e9	[ELF] Don't advance sh_offset for an empty section whose PT_LOAD is removed (due to p_memsz=0) ... removeEmptyPTLoad() removes empty (p_memsz=0) PT_LOAD segments. In assignFileOffsets(), setFileOffset() unnecessarily advances file offsets for containing empty sections. This is exposed by arm Linux kernel's multi_v5_defconfig (see https://bugs.llvm.org/show_bug.cgi?id=45632) ``` ld.lld (max-page-size=65536): [34] .init.data PROGBITS c0c24000 c34000 0128ac 00 WA 0 0 4096 [35] .text_itcm PROGBITS fffe0000 c50000 000000 00 WA 0 0 1 [36] .data_dtcm PROGBITS fffe8000 c58000 000000 00 WA 0 0 1 [37] .data PROGBITS c0c38000 c58000 0647a0 00 WA 0 0 32 arm-linux-gnueabi-ld (max-page-size=65536): [23] .init.data PROGBITS c0c12000 c22000 0128ac 00 WA 0 0 4096 [24] .text_itcm PROGBITS fffe0000 ca2558 000000 00 W 0 0 1 [25] .data_dtcm PROGBITS fffe8000 ca2558 000000 00 W 0 0 1 [26] .data PROGBITS c0c26000 c36000 0647a0 00 WA 0 0 32 ``` This patch clears OutputSection::ptLoad if ptLoad is removed by removeEmptyPTLoad(). Conceptually this removes "dangling" references. Reviewed By: psmith Differential Revision: https://reviews.llvm.org/D79254	2020-05-04 08:07:34 -07:00
Fangrui Song	5c86b08a6f	[ELF][test] Improve tests ... Prepare for the upcomong change that removes unneeded sh_offset advancement for empty sections whose PT_LOAD are removed.	2020-05-01 11:27:51 -07:00
George Rimar	dee900ae59	[LLD][ELF] - Do not remove empty sections referenced in LOADADDR/ADDR commands. ... This is https://bugs.llvm.org//show_bug.cgi?id=38750. If script references empty sections in LOADADDR/ADDR commands .empty : { *(.empty ) } .text : AT(LOADADDR (.empty) + SIZEOF (.empty)) { *(.text) } then an empty section will be removed and LOADADDR/ADDR will evaluate to null. It is not that user may expect from using of the generic script, what is a common case. Differential revision: https://reviews.llvm.org/D54621 llvm-svn: 359279	2019-04-26 06:59:30 +00:00