diff options
Diffstat (limited to 'mach_dep.c')
| -rw-r--r-- | mach_dep.c | 18 |
1 files changed, 12 insertions, 6 deletions
@@ -237,6 +237,7 @@ GC_INNER void GC_with_callee_saves_pushed(void (*fn)(ptr_t, void *), /* Older versions of Darwin seem to lack getcontext(). */ /* ARM and MIPS Linux often doesn't support a real */ /* getcontext(). */ + static signed char getcontext_works = 0; /* (-1) - broken, 1 - works */ ucontext_t ctxt; # ifdef GETCONTEXT_FPU_EXCMASK_BUG /* Workaround a bug (clearing the FPU exception mask) in */ @@ -255,12 +256,17 @@ GC_INNER void GC_with_callee_saves_pushed(void (*fn)(ptr_t, void *), # endif # endif - if (getcontext(&ctxt) < 0) { - WARN("getcontext failed:" - " using another register retrieval method...\n", 0); - /* E.g., to workaround a bug in Docker ubuntu_32bit. */ - } else { - context = &ctxt; + if (getcontext_works >= 0) { + if (getcontext(&ctxt) < 0) { + WARN("getcontext failed:" + " using another register retrieval method...\n", 0); + /* getcontext() is broken, do not try again. */ + /* E.g., to workaround a bug in Docker ubuntu_32bit. */ + } else { + context = &ctxt; + } + if (EXPECT(0 == getcontext_works, FALSE)) + getcontext_works = context != NULL 1 : -1; } # ifdef GETCONTEXT_FPU_EXCMASK_BUG # ifdef X86_64 |