mips64/elfload.c uses #include "../mips/elfload.c" to share code. When
the compiler processes mips/elfload.c the quoted #include "target_elf.h"
resolves relative to the including file's directory, so it picks up
mips/target_elf.h instead of mips64/target_elf.h. mips/target_elf.h
pulls in mips/target_ptrace.h, whose target_pt_regs has a pad0[6] field
before regs[]. As a result elf_core_copy_regs writes:
r->pt.regs[i] -> reserved[6+i] (shifted by 6 from the correct index)
r->pt.cp0_epc -> reserved[40] (correct mips64 N64 index is 34)
The Linux kernel and glibc both use the mips64 N64 layout (no pad0): EPC
at reserved[34]. Debuggers and libunwind reading the core with N64
constants therefore see a completely wrong register set — EPC points to
GP, RA holds the branch target instead of the link address, etc.
Fix by:
- Guarding the mips32 elf_core_copy_regs in mips/elfload.c with #ifndef
TARGET_MIPS64 so it is not compiled for mips64/mipsn32 targets.
- Providing a mips64-specific elf_core_copy_regs in mips64/elfload.c
that writes directly to r->reserved[i] with the correct N64 indices,
bypassing the struct field names that are tainted by the wrong header
include.
The mipsn32 (TARGET_ABI_MIPSN32) and mips64el targets are covered by the
same mips64/elfload.c and benefit from the same fix.
Signed-off-by: Matt Turner <mattst88@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Helge Deller <deller@gmx.de>
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