For mipsn32 (TARGET_ABI32=y, TARGET_LONG_BITS=64):
abi_ulong = uint32_t (4 bytes) — for pointers and ABI-sized fields
target_ulong = uint64_t (8 bytes) — for general-purpose registers
linux-user/elfload.c allocates target_elf_prstatus using the
mips64/target_elf.h definition where target_elf_gregset_t has
target_ulong reserved[45] (8 bytes each, 360 bytes total).
However, in linux-user/mips64/elfload.c, #include "target_elf.h" inside
the included mips/elfload.c resolves to mips/target_elf.h (compiler
searches the file's own directory first), where the union uses abi_ulong
reserved[45]. For mipsn32 this gives 4-byte entries (180 bytes), not
the 8-byte entries (360 bytes) that elfload.c actually allocated.
Writing via r->reserved[34] therefore lands at byte offset 34*4=136
instead of the correct 34*8=272, silently zeroing the EPC in the core
file.
Fix by casting the pointer to target_ulong * so writes always use 8-byte
slots and land at the offsets matching the allocated layout.
This does not change behavior for mips64 (N64) where abi_ulong already
equals target_ulong (both 8 bytes).
Signed-off-by: Matt Turner <mattst88@gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Helge Deller <deller@gmx.de>
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>
Prepare to split the main linux-user/elfload.c.
Create empty files for each target, and add the common build rule.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
