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| author | Dmitry Chagin <dchagin@FreeBSD.org> | 2023-07-07 16:55:28 +0000 |
|---|---|---|
| committer | Dmitry Chagin <dchagin@FreeBSD.org> | 2023-07-07 16:55:28 +0000 |
| commit | ac7759f54574ceb9da48829fd09ea6545404bdc0 (patch) | |
| tree | ed8ce7dafec22f527cb03b2fbac87e335041d677 | |
| parent | 5645dfb41ae0d5ca0acdee8a2a6646787b33e03f (diff) | |
| download | src-ac7759f54574ceb9da48829fd09ea6545404bdc0.tar.gz src-ac7759f54574ceb9da48829fd09ea6545404bdc0.zip | |
rtld: Annotate .rtld_start on aarch64
1. Add a stop indicator to rtld_start to satisfy unwinders on aarch64:
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.
2. Add a proper annotations for CFA.
That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D40844
| -rw-r--r-- | libexec/rtld-elf/aarch64/rtld_start.S | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/libexec/rtld-elf/aarch64/rtld_start.S b/libexec/rtld-elf/aarch64/rtld_start.S index 4f0bef0233b0..107920548432 100644 --- a/libexec/rtld-elf/aarch64/rtld_start.S +++ b/libexec/rtld-elf/aarch64/rtld_start.S @@ -31,15 +31,18 @@ __FBSDID("$FreeBSD$"); ENTRY(.rtld_start) + .cfi_undefined x30 mov x19, x0 /* Put ps_strings in a callee-saved register */ sub sp, sp, #16 /* Make room for obj_main & exit proc */ + .cfi_adjust_cfa_offset 16 mov x1, sp /* exit_proc */ add x2, x1, #8 /* obj_main */ bl _rtld /* Call the loader */ mov x8, x0 /* Backup the entry point */ ldp x2, x1, [sp], #16 /* Load cleanup, obj_main */ + .cfi_adjust_cfa_offset 0 mov x0, x19 /* Restore ps_strings */ br x8 /* Jump to the entry point */ |