components/python/python37/patches/18-obmalloc-adi.patch

   1 From 3956f39e58f0d29487057b523cd68bbd24efc844 Mon Sep 17 00:00:00 2001
   2 From: Aurelien Larcher <aurelien.larcher@gmail.com>
   3 Date: Thu, 11 Jun 2020 13:24:30 +0200
   4 Subject: [PATCH 18/25] 18-obmalloc-adi.patch
   5
   6 ---
   7  Objects/obmalloc.c | 35 ++++++++++++++++++++++++++++++++++-
   8  1 file changed, 34 insertions(+), 1 deletion(-)
   9
  10 diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
  11 index 9408855383..225052df17 100644
  12 --- a/Objects/obmalloc.c
  13 +++ b/Objects/obmalloc.c
  14 @@ -1350,6 +1350,39 @@ obmalloc controls.  Since this test is needed at every entry point, it's
  15  extremely desirable that it be this fast.
  16  */
  17
  18 +#ifdef __sparcv9
  19 +/*
  20 + * Py_ADDRESS_IN_RANGE needs to access memory that might be arbitrarily
  21 + * tagged by an ADI aware allocator. The use of a nonfaulting load
  22 + * guarantees that the read will succeed.
  23 + */
  24 +#ifdef __SUNPRO_C
  25 +
  26 +/* Studio can use built-in nonfaulting load instruction for vis.h */
  27 +#include <vis.h>
  28 +#define POOL_INDEX(x)   __vis_ldswa_ASI_PNF((void*)x)
  29 +
  30 +#else  /* __SUNPRO_C */
  31 +/*
  32 + * GCC doesn't have similar instruction built-in, but it can use
  33 + * following assembly code to do the same.
  34 + */
  35 +
  36 +static inline int vis_ldswa_ASI_PNF(void *arg);
  37 +
  38 +int vis_ldswa_ASI_PNF(void *arg) {
  39 +  int res;
  40 +  __asm__ ("ldswa  [%1]0x82,%0" : "=r" (res) : "r" (arg));
  41 +  return res;
  42 +}
  43 +#define POOL_INDEX(x)   vis_ldswa_ASI_PNF((void*)x)
  44 +
  45 +#endif  /* __SUNPRO_C */
  46 +#else   /* __sparcv9 */
  47 +#define POOL_INDEX(x)   (*(x))
  48 +#endif  /* __sparcv9 */
  49 +
  50 +
  51  static bool _Py_NO_SANITIZE_ADDRESS
  52              _Py_NO_SANITIZE_THREAD
  53              _Py_NO_SANITIZE_MEMORY
  54 @@ -1360,7 +1393,7 @@ address_in_range(void *p, poolp pool)
  55      // another thread may be concurrently modifying the value without holding
  56      // the GIL. The following dance forces the compiler to read pool->arenaindex
  57      // only once.
  58 -    uint arenaindex = *((volatile uint *)&pool->arenaindex);
  59 +    uint arenaindex = (uint)POOL_INDEX((volatile uint *)&pool->arenaindex);
  60      return arenaindex < maxarenas &&
  61          (uintptr_t)p - arenas[arenaindex].address < ARENA_SIZE &&
  62          arenas[arenaindex].address != 0;
  63 --
  64 2.25.4
  65