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authorKonstantin Baladurin <k.baladurin@partner.samsung.com>2018-05-14 09:35:09 (GMT)
committerGleb Balykov <g.balykov@samsung.com>2018-09-18 12:49:14 (GMT)
commit5cc47cbdb69f44772abe0b3f3149468a6706d221 (patch)
tree8d55e57c70f9690b71dd39f669f33171216469aa
parenteaae668fc97b56946e4a01a3ad0c89c11f8259d7 (diff)
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PEImageLayout: flush instruction cache only for pages with relocs.
We need to flush instruction cache only for pages that have relocations instead of full sections because otherwise application's shared clean memory is increased in some cases on Linux.
-rw-r--r--src/vm/peimagelayout.cpp46
1 files changed, 29 insertions, 17 deletions
diff --git a/src/vm/peimagelayout.cpp b/src/vm/peimagelayout.cpp
index a3514e5..5f70363 100644
--- a/src/vm/peimagelayout.cpp
+++ b/src/vm/peimagelayout.cpp
@@ -149,7 +149,10 @@ void PEImageLayout::ApplyBaseRelocations()
SIZE_T cbWriteableRegion = 0;
DWORD dwOldProtection = 0;
- BOOL bRelocDone = FALSE;
+ BYTE * pFlushRegion = NULL;
+ SIZE_T cbFlushRegion = 0;
+ // The page size of PE file relocs is always 4096 bytes
+ const SIZE_T cbPageSize = 4096;
COUNT_T dirPos = 0;
while (dirPos < dirSize)
@@ -184,13 +187,6 @@ void PEImageLayout::ApplyBaseRelocations()
dwOldProtection, &dwOldProtection))
ThrowLastError();
- if (bRelocDone && bExecRegion)
- {
- ClrFlushInstructionCache(pWriteableRegion, cbWriteableRegion);
- }
-
- bRelocDone = FALSE;
-
dwOldProtection = 0;
}
@@ -223,6 +219,7 @@ void PEImageLayout::ApplyBaseRelocations()
}
}
+ BYTE* pEndAddressToFlush = NULL;
for (COUNT_T fixupIndex = 0; fixupIndex < fixupsCount; fixupIndex++)
{
USHORT fixup = VAL16(fixups[fixupIndex]);
@@ -233,13 +230,13 @@ void PEImageLayout::ApplyBaseRelocations()
{
case IMAGE_REL_BASED_PTR:
*(TADDR *)address += delta;
- bRelocDone = TRUE;
+ pEndAddressToFlush = max(pEndAddressToFlush, address + sizeof(TADDR));
break;
#ifdef _TARGET_ARM_
case IMAGE_REL_BASED_THUMB_MOV32:
PutThumb2Mov32((UINT16 *)address, GetThumb2Mov32((UINT16 *)address) + delta);
- bRelocDone = TRUE;
+ pEndAddressToFlush = max(pEndAddressToFlush, address + 8);
break;
#endif
@@ -252,6 +249,24 @@ void PEImageLayout::ApplyBaseRelocations()
}
}
+ BOOL bExecRegion = (dwOldProtection & (PAGE_EXECUTE | PAGE_EXECUTE_READ |
+ PAGE_EXECUTE_READWRITE | PAGE_EXECUTE_WRITECOPY)) != 0;
+
+ if (bExecRegion && pEndAddressToFlush != NULL)
+ {
+ // If the current page is not next to the pending region to flush, flush the current pending region and start a new one
+ if (pageAddress >= pFlushRegion + cbFlushRegion + cbPageSize || pageAddress < pFlushRegion)
+ {
+ if (pFlushRegion != NULL)
+ {
+ ClrFlushInstructionCache(pFlushRegion, cbFlushRegion);
+ }
+ pFlushRegion = pageAddress;
+ }
+
+ cbFlushRegion = pEndAddressToFlush - pFlushRegion;
+ }
+
dirPos += fixupsSize;
}
_ASSERTE(dirSize == dirPos);
@@ -259,18 +274,15 @@ void PEImageLayout::ApplyBaseRelocations()
#ifndef CROSSGEN_COMPILE
if (dwOldProtection != 0)
{
- BOOL bExecRegion = (dwOldProtection & (PAGE_EXECUTE | PAGE_EXECUTE_READ |
- PAGE_EXECUTE_READWRITE | PAGE_EXECUTE_WRITECOPY)) != 0;
-
// Restore the protection
if (!ClrVirtualProtect(pWriteableRegion, cbWriteableRegion,
dwOldProtection, &dwOldProtection))
ThrowLastError();
+ }
- if (bRelocDone && bExecRegion)
- {
- ClrFlushInstructionCache(pWriteableRegion, cbWriteableRegion);
- }
+ if (pFlushRegion != NULL)
+ {
+ ClrFlushInstructionCache(pFlushRegion, cbFlushRegion);
}
#endif // CROSSGEN_COMPILE
}