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[Valgrind-developers] valgrind: r8392 - branches/PTRCHECK/exp-ptrcheck
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From: <sv...@va...> - 2008-07-07 22:00:54
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Author: sewardj
Date: 2008-07-07 23:00:56 +0100 (Mon, 07 Jul 2008)
New Revision: 8392
Log:
* on amd64-linux, handle guest_FS_ZERO and the arch_prctl syscall
correctly. This reduces the false error rate for simple programs
to zero and means it is usable on this platform for the first time.
* some tidying up of the check_store* functions
Modified:
branches/PTRCHECK/exp-ptrcheck/pc_main.c
Modified: branches/PTRCHECK/exp-ptrcheck/pc_main.c
===================================================================
--- branches/PTRCHECK/exp-ptrcheck/pc_main.c 2008-07-07 19:09:11 UTC (rev 8391)
+++ branches/PTRCHECK/exp-ptrcheck/pc_main.c 2008-07-07 22:00:56 UTC (rev 8392)
@@ -1386,6 +1386,8 @@
#if defined(VGA_amd64)
# include "libvex_guest_amd64.h"
# define MC_SIZEOF_GUEST_STATE sizeof(VexGuestAMD64State)
+# define PC_OFF_FS_ZERO offsetof(VexGuestAMD64State,guest_FS_ZERO)
+# define PC_SZB_FS_ZERO sizeof( ((VexGuestAMD64State*)0)->guest_FS_ZERO)
#endif
/* See description on definition of type IntRegInfo. */
@@ -1505,7 +1507,7 @@
if (o == GOF(R14) && is421) { o -= 0; goto contains_o; }
if (o == GOF(R15) && is421) { o -= 0; goto contains_o; }
- if (o == GOF(FS_ZERO) && is8) goto none;
+ if (o == GOF(FS_ZERO) && is8) goto exactly1;
if (o == GOF(SSEROUND) && is8) goto none;
if (o == GOF(XMM0) && isXmmF) goto none;
@@ -1764,6 +1766,8 @@
/*--- System calls ---*/
/*--------------------------------------------------------------------*/
+static __inline__ VG_REGPARM(1) Seg nonptr_or_unknown(UWord x); /*fwds*/
+
static void pre_syscall ( ThreadId tid, UInt syscallno )
{
//zz #if 0
@@ -1799,9 +1803,6 @@
/* For the most part, syscalls don't return pointers. So set
the return shadow to unknown. */
case __NR_access:
-# if defined(__NR_arch_prctl)
- case __NR_arch_prctl:
-# endif
case __NR_clock_gettime:
case __NR_close:
# if defined(__NR_connect)
@@ -1898,6 +1899,18 @@
VG_(set_syscall_return_shadows)( tid, (UWord)NONPTR, 0 );
break;
+# if defined(__NR_arch_prctl)
+ case __NR_arch_prctl: {
+ put_guest_intreg(
+ tid, 1/*shadowno*/, PC_OFF_FS_ZERO, PC_SZB_FS_ZERO,
+ (UWord)
+ nonptr_or_unknown(
+ get_guest_intreg( tid, 0/*shadowno*/,
+ PC_OFF_FS_ZERO, PC_SZB_FS_ZERO )));
+ VG_(set_syscall_return_shadows)( tid, (UWord)NONPTR, 0 );
+ }
+# endif
+
//zz // These ones don't return a pointer, so don't do anything -- already set
//zz // the segment to UNKNOWN in post_reg_write_default().
//zz // 1: // exit (never seen by skin)
@@ -2234,15 +2247,29 @@
// ------------------ Store handlers ------------------ //
/* On 32 bit targets, we will use:
- check_store1 check_store2 check_store4W
+ check_store1 check_store2 check_store4_P
On 64 bit targets, we will use:
- check_store1 check_store2 check_store4 check_store8W
+ check_store1 check_store2 check_store4 check_store8_P
*/
+/* Apply nonptr_or_unknown to all the words intersecting
+ [a, a+len). */
+static void pessimise_words_intersecting ( Addr a, SizeT len )
+{
+ const SizeT wszB = sizeof(UWord);
+ Addr wfirst = VG_ROUNDDN(a, wszB);
+ Addr wlast = VG_ROUNDDN(a+len-1, wszB);
+ Addr a2;
+ tl_assert(wfirst <= wlast);
+ for (a2 = wfirst ; a2 <= wlast; a2 += wszB) {
+ set_mem_vseg( a2, nonptr_or_unknown( *(UWord*)a2 ));
+ }
+}
+
// This handles 64 bit stores on 64 bit targets. It must
// not be called on 32 bit targets.
static VG_REGPARM(3)
-void check_store8W(Addr m, Seg mptr_vseg, UWord t, Seg t_vseg)
+void check_store8_P(Addr m, Seg mptr_vseg, UWord t, Seg t_vseg)
{
tl_assert(sizeof(UWord) == 8); /* DO NOT REMOVE */
checkSeg(t_vseg);
@@ -2254,17 +2281,14 @@
set_mem_vseg( m, t_vseg );
} else {
// straddling two words
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- m += 8;
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
+ pessimise_words_intersecting(m, 8);
}
}
// This handles 32 bit stores on 32 bit targets. It must
// not be called on 64 bit targets.
static VG_REGPARM(3)
-void check_store4W(Addr m, Seg mptr_vseg, UWord t, Seg t_vseg)
+void check_store4_P(Addr m, Seg mptr_vseg, UWord t, Seg t_vseg)
{
tl_assert(sizeof(UWord) == 4); /* DO NOT REMOVE */
checkSeg(t_vseg);
@@ -2276,10 +2300,7 @@
set_mem_vseg( m, t_vseg );
} else {
// straddling two words
- m = VG_ROUNDDN(m,4);
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
- m += 4;
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
+ pessimise_words_intersecting(m, 4);
}
}
@@ -2293,19 +2314,7 @@
check_load_or_store(/*is_write*/True, m, 4, mptr_vseg);
// Actually *do* the STORE here (Nb: cast must be to 4-byte type!)
*(UInt*)m = t;
- if (0 == (m & 4)) {
- // within one word. This happens if the address ends in
- // 000, 001, 010, 011. If it ends in 100, 101, 110, 111
- // then it overlaps two adjacent 64 bit words.
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- } else {
- // straddling two words
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- m += 8;
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- }
+ pessimise_words_intersecting(m, 4);
}
// Used for both 32 bit and 64 bit targets.
@@ -2316,33 +2325,7 @@
check_load_or_store(/*is_write*/True, m, 2, mptr_vseg);
// Actually *do* the STORE here (Nb: cast must be to 2-byte type!)
*(UShort*)m = t;
- if (sizeof(UWord) == 4) {
- /* 32-bit host */
- if (3 != (m & 3)) {
- // within one word
- m = VG_ROUNDDN(m,4);
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
- } else {
- // straddling two words
- m = VG_ROUNDDN(m,4);
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
- m += 4;
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
- }
- } else {
- /* 64-bit host */
- if (7 != (m & 7)) {
- // within one word
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- } else {
- // straddling two words
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- m += 8;
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- }
- }
+ pessimise_words_intersecting(m, 2);
}
// Used for both 32 bit and 64 bit targets.
@@ -2353,15 +2336,7 @@
check_load_or_store(/*is_write*/True, m, 1, mptr_vseg);
// Actually *do* the STORE here (Nb: cast must be to 1-byte type!)
*(UChar*)m = t;
- if (sizeof(UWord) == 4) {
- /* 32-bit host */
- m = VG_ROUNDDN(m,4);
- set_mem_vseg( m, nonptr_or_unknown( *(UInt*)m ) );
- } else {
- /* 64-bit host */
- m = VG_ROUNDDN(m,8);
- set_mem_vseg( m, nonptr_or_unknown( *(ULong*)m ) );
- }
+ pessimise_words_intersecting(m, 1);
}
//zz
@@ -3540,8 +3515,8 @@
if (pce->gWordTy == Ity_I32) {
/* 32 bit host/guest (cough, cough) */
switch (d_ty) {
- case Ity_I32: h_fn = &check_store4W;
- h_nm = "check_store4W"; break;
+ case Ity_I32: h_fn = &check_store4_P;
+ h_nm = "check_store4_P"; break;
case Ity_I16: h_fn = &check_store2;
h_nm = "check_store2"; break;
case Ity_I8: h_fn = &check_store1;
@@ -3560,8 +3535,8 @@
} else {
/* 64 bit host/guest (cough, cough) */
switch (d_ty) {
- case Ity_I64: h_fn = &check_store8W;
- h_nm = "check_store8W"; break;
+ case Ity_I64: h_fn = &check_store8_P;
+ h_nm = "check_store8_P"; break;
case Ity_I32: h_fn = &check_store4;
h_nm = "check_store4"; break;
case Ity_I16: h_fn = &check_store2;
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