fix(verify): fix non-amd64 JIT trampolines and validate under qemu

CHANGELOG.md

@@ -11,10 +11,13 @@ Unreleased changes on the `development` branch.
 
 ### Added
 
-- **Multi-architecture debugger.**  `gasm debug` works on arm64, riscv64
-  and loong64 in addition to amd64.  Each architecture has its own ptrace
-  register access, disassembler (`golang.org/x/arch`), register display,
-  and stop-info handler.  The REPL is fully arch-neutral.
+- **Multi-architecture debugger.**  `gasm debug` carries
+  per-architecture ptrace register access, disassemblers
+  (`golang.org/x/arch`), register display, FP register views and
+  stop-info handlers for arm64, riscv64 and loong64, and the REPL is
+  arch-neutral.  Sessions are runtime-validated on amd64; the other
+  hosts execute through the now-working JIT trampolines, but their
+  ptrace loops have not seen hardware yet.
 - **Headless debugging.**  `gasm debug --script` runs REPL commands from a
   file (or stdin) and exits; `--timeout` kills the debuggee when a run
   hangs, with the watchdog armed before the ptrace attach.  `--cover` runs
@@ -43,18 +46,22 @@ Unreleased changes on the `development` branch.
   architectures via hand-written assembly trampolines
   (`trampoline_{arm64,riscv64,loong64}.s`) that save the Go stack, switch
   to a prepared stack, and branch to the JIT function.
-- **ABI checks architecture port (partial).**  The ABI-checking
-  machinery is architecture-neutral (`ABIReport` with `FPClobbered`,
-  `GClobbered`, `RedZoneHit`; renamed from the amd64-only field names)
-  and per-architecture checked trampolines exist for arm64, riscv64 and
-  loong64 alongside amd64, restoring the frame pointer and the goroutine
-  pointer before returning into Go code.  Runtime execution of the
-  non-amd64 JIT paths is not yet reliable (arm64 and loong64 fault on the
-  return path and riscv64 returns a wrong result under qemu-user), so
-  `gasm verify` keeps JIT execution gated to amd64 kernels on amd64
-  hosts; other kernels take the toolchain-comparison path exactly as
-  before.  A qemu-user harness and GOARCH-guarded tests are in the tree
-  to validate the trampolines once their return path is fixed.
+- **ABI checks on all architectures.**  `gasm verify -abi` and the ABI
+  half of `-fuzz` now work on arm64, riscv64 and loong64 via
+  per-architecture checked trampolines: sentinels planted in the
+  registers the Go ABI fixes across calls (amd64 `BP`/`R14`, arm64
+  `R29`/`R28`, riscv64 `X27`, loong64 `R22`) are verified on return and
+  the saved registers restored before Go code resumes, with the
+  below-SP canary on every architecture.  The root cause of the broken
+  non-amd64 calls was a stack misalignment: the trampolines advanced SP
+  past the linkage slot while the kernels read their first argument at
+  SP+8.  riscv64 is validated end to end under qemu-user; arm64 shares
+  the fix and matches the observed frame convention; loong64 stays
+  ground-truth-only until hardware validation (the Go runtime cannot
+  start under the available loong64 emulators).  `verify.Load` now
+  assembles each file with the encoder its name suffix calls for.  The
+  `ABIReport` fields are renamed to the architecture-neutral
+  `FPClobbered` and `GClobbered`.
 - **Hardware watchpoints on all architectures.**  arm64 uses DBGWVR/DBGWCR
   via `PTRACE_SETREGSET` with `NT_ARM_HW_BREAK`; riscv64 and loong64 use
   `PTRACE_POKEUSER` to access trigger/debug registers.