diff options
Diffstat (limited to 'src/pkg/runtime/symtab.c')
| -rw-r--r-- | src/pkg/runtime/symtab.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/src/pkg/runtime/symtab.c b/src/pkg/runtime/symtab.c index da4579734..d2ebf9b40 100644 --- a/src/pkg/runtime/symtab.c +++ b/src/pkg/runtime/symtab.c @@ -78,6 +78,7 @@ static int32 nfunc; static byte **fname; static int32 nfname; +static uint32 funcinit; static Lock funclock; static void @@ -159,7 +160,7 @@ makepath(byte *buf, int32 nbuf, byte *path) break; if(p > buf && p[-1] != '/') *p++ = '/'; - runtime·mcpy(p, q, len+1); + runtime·memmove(p, q, len+1); p += len; } } @@ -420,10 +421,21 @@ runtime·findfunc(uintptr addr) Func *f; int32 nf, n; - runtime·lock(&funclock); - if(func == nil) - buildfuncs(); - runtime·unlock(&funclock); + // Use atomic double-checked locking, + // because when called from pprof signal + // handler, findfunc must run without + // grabbing any locks. + // (Before enabling the signal handler, + // SetCPUProfileRate calls findfunc to trigger + // the initialization outside the handler.) + if(runtime·atomicload(&funcinit) == 0) { + runtime·lock(&funclock); + if(funcinit == 0) { + buildfuncs(); + runtime·atomicstore(&funcinit, 1); + } + runtime·unlock(&funclock); + } if(nfunc == 0) return nil; |