diff options
Diffstat (limited to 'src/runtime/os_linux.go')
| -rw-r--r-- | src/runtime/os_linux.go | 79 |
1 files changed, 41 insertions, 38 deletions
diff --git a/src/runtime/os_linux.go b/src/runtime/os_linux.go index 78899737b6..98e7f52b9e 100644 --- a/src/runtime/os_linux.go +++ b/src/runtime/os_linux.go @@ -89,13 +89,13 @@ func getproccount() int32 { // buffers, but we don't have a dynamic memory allocator at the // moment, so that's a bit tricky and seems like overkill. const maxCPUs = 64 * 1024 - var buf [maxCPUs / (sys.PtrSize * 8)]uintptr + var buf [maxCPUs / 8]byte r := sched_getaffinity(0, unsafe.Sizeof(buf), &buf[0]) if r < 0 { return 1 } n := int32(0) - for _, v := range buf[:r/sys.PtrSize] { + for _, v := range buf[:r] { for v != 0 { n += int32(v & 1) v >>= 1 @@ -193,6 +193,8 @@ const ( var procAuxv = []byte("/proc/self/auxv\x00") +func mincore(addr unsafe.Pointer, n uintptr, dst *byte) int32 + func sysargs(argc int32, argv **byte) { n := argc + 1 @@ -206,45 +208,46 @@ func sysargs(argc int32, argv **byte) { // now argv+n is auxv auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize)) - if sysauxv(auxv[:]) == 0 { - // In some situations we don't get a loader-provided - // auxv, such as when loaded as a library on Android. - // Fall back to /proc/self/auxv. - fd := open(&procAuxv[0], 0 /* O_RDONLY */, 0) - if fd < 0 { - // On Android, /proc/self/auxv might be unreadable (issue 9229), so we fallback to - // try using mincore to detect the physical page size. - // mincore should return EINVAL when address is not a multiple of system page size. - const size = 256 << 10 // size of memory region to allocate - p := mmap(nil, size, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0) - if uintptr(p) < 4096 { - return - } - var n uintptr - for n = 4 << 10; n < size; n <<= 1 { - err := mincore(unsafe.Pointer(uintptr(p)+n), 1, &addrspace_vec[0]) - if err == 0 { - physPageSize = n - break - } - } - if physPageSize == 0 { - physPageSize = size - } - munmap(p, size) + if sysauxv(auxv[:]) != 0 { + return + } + // In some situations we don't get a loader-provided + // auxv, such as when loaded as a library on Android. + // Fall back to /proc/self/auxv. + fd := open(&procAuxv[0], 0 /* O_RDONLY */, 0) + if fd < 0 { + // On Android, /proc/self/auxv might be unreadable (issue 9229), so we fallback to + // try using mincore to detect the physical page size. + // mincore should return EINVAL when address is not a multiple of system page size. + const size = 256 << 10 // size of memory region to allocate + p, err := mmap(nil, size, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0) + if err != 0 { return } - var buf [128]uintptr - n := read(fd, noescape(unsafe.Pointer(&buf[0])), int32(unsafe.Sizeof(buf))) - closefd(fd) - if n < 0 { - return + var n uintptr + for n = 4 << 10; n < size; n <<= 1 { + err := mincore(unsafe.Pointer(uintptr(p)+n), 1, &addrspace_vec[0]) + if err == 0 { + physPageSize = n + break + } + } + if physPageSize == 0 { + physPageSize = size } - // Make sure buf is terminated, even if we didn't read - // the whole file. - buf[len(buf)-2] = _AT_NULL - sysauxv(buf[:]) + munmap(p, size) + return + } + var buf [128]uintptr + n = read(fd, noescape(unsafe.Pointer(&buf[0])), int32(unsafe.Sizeof(buf))) + closefd(fd) + if n < 0 { + return } + // Make sure buf is terminated, even if we didn't read + // the whole file. + buf[len(buf)-2] = _AT_NULL + sysauxv(buf[:]) } func sysauxv(auxv []uintptr) int { @@ -382,7 +385,7 @@ func raise(sig uint32) func raiseproc(sig uint32) //go:noescape -func sched_getaffinity(pid, len uintptr, buf *uintptr) int32 +func sched_getaffinity(pid, len uintptr, buf *byte) int32 func osyield() //go:nosplit |