diff options
| -rw-r--r-- | misc/wasm/wasm_exec.js | 7 | ||||
| -rw-r--r-- | src/cmd/link/internal/ld/data.go | 11 |
2 files changed, 17 insertions, 1 deletions
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js index 82041e6bb90..a0a264278b1 100644 --- a/misc/wasm/wasm_exec.js +++ b/misc/wasm/wasm_exec.js @@ -564,6 +564,13 @@ offset += 8; }); + // The linker guarantees global data starts from at least wasmMinDataAddr. + // Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr. + const wasmMinDataAddr = 4096 + 4096; + if (offset >= wasmMinDataAddr) { + throw new Error("command line too long"); + } + this._inst.exports.run(argc, argv); if (this.exited) { this._resolveExitPromise(); diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go index 52035e96301..54a1d188cdb 100644 --- a/src/cmd/link/internal/ld/data.go +++ b/src/cmd/link/internal/ld/data.go @@ -2330,6 +2330,11 @@ func assignAddress(ctxt *Link, sect *sym.Section, n int, s loader.Sym, va uint64 return sect, n, va } +// On Wasm, we reserve 4096 bytes for zero page, then 4096 bytes for wasm_exec.js +// to store command line args. Data sections starts from at least address 8192. +// Keep in sync with wasm_exec.js. +const wasmMinDataAddr = 4096 + 4096 + // address assigns virtual addresses to all segments and sections and // returns all segments in file order. func (ctxt *Link) address() []*sym.Segment { @@ -2339,10 +2344,14 @@ func (ctxt *Link) address() []*sym.Segment { order = append(order, &Segtext) Segtext.Rwx = 05 Segtext.Vaddr = va - for _, s := range Segtext.Sections { + for i, s := range Segtext.Sections { va = uint64(Rnd(int64(va), int64(s.Align))) s.Vaddr = va va += s.Length + + if ctxt.IsWasm() && i == 0 && va < wasmMinDataAddr { + va = wasmMinDataAddr + } } Segtext.Length = va - uint64(*FlagTextAddr) |