gawk/pma.patch
Dirk Mueller d059de2dbc Accepting request 1004924 from home:Andreas_Schwab:Factory
- double-free.patch: Fix Node_elem_new op, replacing upref.patch
- pma.patch: Replace with upstream solution
- nan-sign.patch: Fix negative NaN issue on RiscV, replacing
  nan-tests.patch

OBS-URL: https://build.opensuse.org/request/show/1004924
OBS-URL: https://build.opensuse.org/package/show/Base:System/gawk?expand=0&rev=91
2022-09-20 11:27:14 +00:00

41 lines
2.2 KiB
Diff

Index: gawk-5.2.0/support/pma.c
===================================================================
--- gawk-5.2.0.orig/support/pma.c
+++ gawk-5.2.0/support/pma.c
@@ -340,16 +340,20 @@ static void flr(ao_t *p) { // remove ao
#define MMAP(N) mmap(NULL, (N), PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0)
#define MUNMAP(A, N) do { if (0 != munmap((A), (N))) { ERR("munmap()" ERN); SERN; } } while (0)
static void * addrgap(off_t n) { // find big gap in address space to map n bytes
- void *A, *Amax = NULL; size_t L = 0, U, Max = 0, N = (size_t)n; char *r;
+ void *A, *Amax = NULL; size_t L, U, Max = 0, N = (size_t)n; char *r;
FYI("addrgap(%jd)\n", (intmax_t)n); // TODO: better way to handle off_t
if (N < sizeof(pma_hdr_t) + 40960) { ERR("file size %zu too small\n", N); SERN; }
- for (U = 1; ; U *= 2) // double upper bound until failure
- if (MAP_FAILED == (A = MMAP(U))) break;
- else MUNMAP(A, U);
- while (1 + L < U) { // binary search between bounds
+ // Binary search to find max length of successfull mmap().
+ // Invariants:
+ // Larger max might lie in range [L,U] inclusive.
+ // If a previous max has been found, it must lie in [1,L-1].
+ // A larger max cannot lie in [U+1,UINT64_MAX].
+ L = 1; // mmap fails if length == 0 (SUSv3)
+ U = UINT64_MAX;
+ while (L <= U) {
size_t M = L + (U - L) / 2; // avoid overflow
- if (MAP_FAILED == (A = MMAP(M))) { U = M; }
- else { Amax = A; Max = M; MUNMAP(A, M); L = M; }
+ if (MAP_FAILED != (A = MMAP(M))) { assert(Max < M); Max = M; Amax = A; MUNMAP(A, M); if (UINT64_MAX == M) break; L = M + 1; }
+ else { assert(0 < M); U = M - 1; }
}
FYI("max gap: %zu bytes at %p\n", Max, Amax);
if (Max < N + (size_t)ALGN * 2) { // safety margin
@@ -392,6 +396,7 @@ int pma_init(int verbose, const char *fi
assert((himask | lomask) == ~((uintptr_t)0));
if (! (WDSZ == sizeof(void *) && // in C11 we'd static_assert()
WDSZ == sizeof(size_t) &&
+ WDSZ == sizeof(off_t) &&
WDSZ == sizeof(unsigned long))) { ERR("word size not 64 bits\n"); SERL; }
assert(0 == sizeof(pma_hdr_t) % WDSZ);
if (NULL == file) {