Merge r6806 from branches/THRCHECK:

Fix longstanding error in the amd64-linux function-wrapping macros:
protect the caller's red zone across the hidden call.  All rather
nasty as explained in big comment.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7120 a5019735-40e9-0310-863c-91ae7b9d1cf9

1 files changed, 47 insertions, 0 deletions

diff --git a/include/valgrind.h b/include/valgrind.h
index 20c5d0ead..f18cc97e3 100644
--- a/include/valgrind.h
+++ b/include/valgrind.h
@@ -1022,6 +1022,27 @@ typedef
 /* These CALL_FN_ macros assume that on amd64-linux, sizeof(unsigned
    long) == 8. */
 
+/* NB 9 Sept 07.  There is a nasty kludge here in all these CALL_FN_
+   macros.  In order not to trash the stack redzone, we need to drop
+   %rsp by 128 before the hidden call, and restore afterwards.  The
+   nastyness is that it is only by luck that the stack still appears
+   to be unwindable during the hidden call - since then the behaviour
+   of any routine using this macro does not match what the CFI data
+   says.  Sigh.
+
+   Why is this important?  Imagine that a wrapper has a stack
+   allocated local, and passes to the hidden call, a pointer to it.
+   Because gcc does not know about the hidden call, it may allocate
+   that local in the redzone.  Unfortunately the hidden call may then
+   trash it before it comes to use it.  So we must step clear of the
+   redzone, for the duration of the hidden call, to make it safe.
+
+   Probably the same problem afflicts the other redzone-style ABIs too
+   (ppc64-linux, ppc32-aix5, ppc64-aix5); but for those, the stack is
+   self describing (none of this CFI nonsense) so at least messing
+   with the stack pointer doesn't give a danger of non-unwindable
+   stack. */
+
 #define CALL_FN_W_v(lval, orig)                                   \
    do {                                                           \
       volatile OrigFn        _orig = (orig);                      \
@@ -1029,8 +1050,10 @@ typedef
       volatile unsigned long _res;                                \
       _argvec[0] = (unsigned long)_orig.nraddr;                   \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1046,9 +1069,11 @@ typedef
       _argvec[0] = (unsigned long)_orig.nraddr;                   \
       _argvec[1] = (unsigned long)(arg1);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1065,10 +1090,12 @@ typedef
       _argvec[1] = (unsigned long)(arg1);                         \
       _argvec[2] = (unsigned long)(arg2);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 16(%%rax), %%rsi\n\t"                              \
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1086,11 +1113,13 @@ typedef
       _argvec[2] = (unsigned long)(arg2);                         \
       _argvec[3] = (unsigned long)(arg3);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 24(%%rax), %%rdx\n\t"                              \
          "movq 16(%%rax), %%rsi\n\t"                              \
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1109,12 +1138,14 @@ typedef
       _argvec[3] = (unsigned long)(arg3);                         \
       _argvec[4] = (unsigned long)(arg4);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 32(%%rax), %%rcx\n\t"                              \
          "movq 24(%%rax), %%rdx\n\t"                              \
          "movq 16(%%rax), %%rsi\n\t"                              \
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1134,6 +1165,7 @@ typedef
       _argvec[4] = (unsigned long)(arg4);                         \
       _argvec[5] = (unsigned long)(arg5);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 40(%%rax), %%r8\n\t"                               \
          "movq 32(%%rax), %%rcx\n\t"                              \
          "movq 24(%%rax), %%rdx\n\t"                              \
@@ -1141,6 +1173,7 @@ typedef
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1161,6 +1194,7 @@ typedef
       _argvec[5] = (unsigned long)(arg5);                         \
       _argvec[6] = (unsigned long)(arg6);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "movq 48(%%rax), %%r9\n\t"                               \
          "movq 40(%%rax), %%r8\n\t"                               \
          "movq 32(%%rax), %%rcx\n\t"                              \
@@ -1168,6 +1202,7 @@ typedef
          "movq 16(%%rax), %%rsi\n\t"                              \
          "movq 8(%%rax), %%rdi\n\t"                               \
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
+         "addq $128,%%rsp\n\t"                                    \
          VALGRIND_CALL_NOREDIR_RAX                                \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
@@ -1191,6 +1226,7 @@ typedef
       _argvec[6] = (unsigned long)(arg6);                         \
       _argvec[7] = (unsigned long)(arg7);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 56(%%rax)\n\t"                                    \
          "movq 48(%%rax), %%r9\n\t"                               \
          "movq 40(%%rax), %%r8\n\t"                               \
@@ -1201,6 +1237,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $8, %%rsp\n"                                       \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1224,6 +1261,7 @@ typedef
       _argvec[7] = (unsigned long)(arg7);                         \
       _argvec[8] = (unsigned long)(arg8);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 64(%%rax)\n\t"                                    \
          "pushq 56(%%rax)\n\t"                                    \
          "movq 48(%%rax), %%r9\n\t"                               \
@@ -1235,6 +1273,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $16, %%rsp\n"                                      \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1259,6 +1298,7 @@ typedef
       _argvec[8] = (unsigned long)(arg8);                         \
       _argvec[9] = (unsigned long)(arg9);                         \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 72(%%rax)\n\t"                                    \
          "pushq 64(%%rax)\n\t"                                    \
          "pushq 56(%%rax)\n\t"                                    \
@@ -1271,6 +1311,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $24, %%rsp\n"                                      \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1296,6 +1337,7 @@ typedef
       _argvec[9] = (unsigned long)(arg9);                         \
       _argvec[10] = (unsigned long)(arg10);                       \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 80(%%rax)\n\t"                                    \
          "pushq 72(%%rax)\n\t"                                    \
          "pushq 64(%%rax)\n\t"                                    \
@@ -1309,6 +1351,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $32, %%rsp\n"                                      \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1335,6 +1378,7 @@ typedef
       _argvec[10] = (unsigned long)(arg10);                       \
       _argvec[11] = (unsigned long)(arg11);                       \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 88(%%rax)\n\t"                                    \
          "pushq 80(%%rax)\n\t"                                    \
          "pushq 72(%%rax)\n\t"                                    \
@@ -1349,6 +1393,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $40, %%rsp\n"                                      \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \
@@ -1376,6 +1421,7 @@ typedef
       _argvec[11] = (unsigned long)(arg11);                       \
       _argvec[12] = (unsigned long)(arg12);                       \
       __asm__ volatile(                                           \
+         "subq $128,%%rsp\n\t"                                    \
          "pushq 96(%%rax)\n\t"                                    \
          "pushq 88(%%rax)\n\t"                                    \
          "pushq 80(%%rax)\n\t"                                    \
@@ -1391,6 +1437,7 @@ typedef
          "movq (%%rax), %%rax\n\t"  /* target->%rax */            \
          VALGRIND_CALL_NOREDIR_RAX                                \
          "addq $48, %%rsp\n"                                      \
+         "addq $128,%%rsp\n\t"                                    \
          : /*out*/   "=a" (_res)                                  \
          : /*in*/    "a" (&_argvec[0])                            \
          : /*trash*/ "cc", "memory", __CALLER_SAVED_REGS          \