qemu/qemu.git/linux-user/mips64, branch master

linux-user/mips: write the floating-point registers to a core dump

2026-08-07T16:14:13+00:00

Write an NT_FPREGSET note for MIPS and MIPS64, matching the kernel's elf_fpregset_t layout (ELF_NFPREG = 33): fpr[0..31] hold f0-f31, and fcsr occupies the low 32 bits of slot 32. The pad field rounds the struct to 33 × 8 bytes = 264 bytes. Signed-off-by: Matt Turner Reviewed-by: Helge Deller Signed-off-by: Helge Deller

linux-user/mips64: fix mipsn32 elf_core_copy_regs entry width

2026-05-24T13:07:28+00:00

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 Cc: qemu-stable@nongnu.org Signed-off-by: Helge Deller

linux-user/mips64: fix elf_core_copy_regs register layout in core files

2026-05-24T13:07:28+00:00

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 Cc: qemu-stable@nongnu.org Signed-off-by: Helge Deller

linux-user/mips, target/mips: honor MIPS_FIXADE for unaligned accesses

2026-05-21T06:20:58+00:00

Linux/MIPS enables software fixups for user-mode unaligned scalar accesses by default through MIPS_FIXADE/TIF_FIXADE. QEMU linux-user did not model that ABI, so MIPS guests took fatal AdEL/AdES exceptions unless translation was forced to use unaligned host accesses. Key MIPS translation blocks on the linux-user unaligned policy, implement sysmips(MIPS_FIXADE) to toggle that policy, and raise SIGBUS/BUS_ADRALN when fixups are disabled. Reviewed-by: Richard Henderson Signed-off-by: James Hilliard Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20260520172313.23777-4-philmd@linaro.org>

linux-user/mips: implement sysmips(MIPS_ATOMIC_SET)

2026-05-21T06:20:58+00:00

Implement the MIPS_ATOMIC_SET sysmips command as an aligned 32-bit atomic exchange in target memory. MIPS reports syscall errors through a separate register, so successful old values can overlap the errno range. Write the return value and error flag directly and return -QEMU_ESIGRETURN so the common syscall path leaves the registers unchanged. Reviewed-by: Richard Henderson Signed-off-by: James Hilliard Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20260520172313.23777-3-philmd@linaro.org>

linux-user/mips: implement sysmips(MIPS_FLUSH_CACHE)

2026-05-21T06:20:58+00:00

Add the target sysmips dispatcher and implement MIPS_FLUSH_CACHE as a successful no-op for linux-user. Self-modifying code is handled by QEMU's normal user-mode translation invalidation machinery, so the target ABI only needs the syscall command to be accepted. Reviewed-by: Richard Henderson Signed-off-by: James Hilliard Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20260520172313.23777-2-philmd@linaro.org>

linux-user: Standardize on ELF_MACHINE not ELF_ARCH

2025-08-29T21:04:04+00:00

PowerPC was the one outlier that defined both ELF_ARCH and ELF_MACHINE; ELF_ARCH was defined incorrectly, necessitating the definition of elf_check_arch. However, the elf file header field in question is called e_machine, so ELF_MACHINE is in fact the better name. Mechanically change most target/target_elf.h files, then adjust ppc/target_elf.h manually. Do not provide a default for ELF_MACHINE. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson

linux-user: Move elf parameters to {mips,mips64}/target_elf.h

2025-08-29T21:04:04+00:00

Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson

linux-user/mips: Use target_ulong for target_elf_greg_t

2025-08-29T21:04:04+00:00

Make use of the fact that target_elf_gregset_t is a proper structure. The target_ulong type matches the abi_ulong/abi_ullong selection within mips64/target_elf.h. Drop ELF_NREG, target_elf_greg_t, and tswapreg. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson

linux-user/mips: Create target_ptrace.h

2025-08-29T21:04:04+00:00

Move the target_pt_regs structure from target_syscall.h. Fix the incorrect ordering of the fields. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson