The branch main has been updated by dchagin: URL: https://cgit.FreeBSD.org/src/commit/?id=e541cf8316bb787df0f19c43132c517482cf24a6
commit e541cf8316bb787df0f19c43132c517482cf24a6 Author: Dmitry Chagin <[email protected]> AuthorDate: 2023-07-11 12:10:32 +0000 Commit: Dmitry Chagin <[email protected]> CommitDate: 2023-07-11 12:10:32 +0000 rtld: Annotate .rtld_start on i386 Add a stop indicator to rtld_start to satisfy unwinders: The right unwinding stop indicator should be CFI-undefined PC. https://dwarfstd.org/doc/Dwarf3.pdf - page 118: If a Return Address register is defined in the virtual unwind table, and its rule is undefined (for example, by DW_CFA_undefined), then there is no return address and no call address, and the virtual unwind of stack activations is complete. That is allows gdb and libunwind successfully stop when unwinding stack from global constructors and destructors. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D40949 --- libexec/rtld-elf/i386/rtld_start.S | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libexec/rtld-elf/i386/rtld_start.S b/libexec/rtld-elf/i386/rtld_start.S index 6dbae220d89c..656ebb13864f 100644 --- a/libexec/rtld-elf/i386/rtld_start.S +++ b/libexec/rtld-elf/i386/rtld_start.S @@ -30,8 +30,15 @@ .globl .rtld_start .type .rtld_start,@function .rtld_start: + .cfi_startproc + .cfi_undefined %eip xorl %ebp,%ebp # Clear frame pointer for good form movl %esp,%esi # Save initial stack pointer + pushl %ebp + .cfi_def_cfa_offset 4 + movl %esp,%ebp + .cfi_offset %ebp,-4 + .cfi_def_cfa_register %ebp andl $0xfffffff0,%esp # Align stack pointer subl $16,%esp # A place to store exit procedure addr movl %esp,%ebx # save address of exit proc @@ -53,6 +60,7 @@ .globl .rtld_goto_main .rtld_goto_main: # This symbol exists just to make debugging easier. jmp *%eax # Enter main program + .cfi_endproc /*
