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Implemented binary search of the export tables

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svn path=/trunk/; revision=1605
This commit is contained in:
David Welch 2001-02-06 02:03:35 +00:00
parent b2fe7525bf
commit bcc1b4e9a5
1 changed files with 72 additions and 67 deletions
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139
reactos/lib/ntdll/ldr/utils.c
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@ -1,4 +1,4 @@
/* $Id: utils.c,v 1.36 2001/01/23 04:37:13 phreak Exp $
/* $Id: utils.c,v 1.37 2001/02/06 02:03:35 dwelch Exp $
*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
@ -638,73 +638,77 @@ LdrGetExportByOrdinal (
*
*/
static PVOID
LdrGetExportByName (
PVOID BaseAddress,
PUCHAR SymbolName
)
LdrGetExportByName (PVOID BaseAddress,
PUCHAR SymbolName)
{
PIMAGE_EXPORT_DIRECTORY ExportDir;
PDWORD * ExFunctions;
PDWORD * ExNames;
USHORT * ExOrdinals;
ULONG i;
PVOID ExName;
ULONG Ordinal;
PIMAGE_EXPORT_DIRECTORY ExportDir;
PDWORD * ExFunctions;
PDWORD * ExNames;
USHORT * ExOrdinals;
ULONG i;
PVOID ExName;
ULONG Ordinal;
ULONG minn, maxn;
// DPRINT(
// "LdrFindExport(Module %x, SymbolName %s)\n",
// Module,
// SymbolName
// );
ExportDir = (PIMAGE_EXPORT_DIRECTORY)
RtlImageDirectoryEntryToData (BaseAddress,
TRUE,
IMAGE_DIRECTORY_ENTRY_EXPORT,
NULL);
ExportDir = (PIMAGE_EXPORT_DIRECTORY)
RtlImageDirectoryEntryToData (BaseAddress,
TRUE,
IMAGE_DIRECTORY_ENTRY_EXPORT,
NULL);
/*
* Get header pointers
*/
ExNames = (PDWORD *)RVA(BaseAddress,
ExportDir->AddressOfNames);
ExOrdinals = (USHORT *)RVA(BaseAddress,
ExportDir->AddressOfNameOrdinals);
ExFunctions = (PDWORD *)RVA(BaseAddress,
ExportDir->AddressOfFunctions);
/*
* Get header pointers
*/
ExNames = (PDWORD *)
RVA(
BaseAddress,
ExportDir->AddressOfNames
);
ExOrdinals = (USHORT *)
RVA(
BaseAddress,
ExportDir->AddressOfNameOrdinals
);
ExFunctions = (PDWORD *)
RVA(
BaseAddress,
ExportDir->AddressOfFunctions
);
for ( i = 0;
( i < ExportDir->NumberOfFunctions);
i++
)
/*
* Try a binary search first
*/
minn = 0, maxn = ExportDir->NumberOfFunctions;
while (minn <= maxn)
{
ULONG mid;
LONG res;
mid = (minn + maxn) / 2;
ExName = RVA(BaseAddress, ExNames[mid]);
res = strcmp(ExName, SymbolName);
if (res == 0)
{
ExName = RVA(
BaseAddress,
ExNames[i]
);
// DPRINT(
// "Comparing '%s' '%s'\n",
// ExName,
// SymbolName
// );
if (strcmp(ExName,SymbolName) == 0)
{
Ordinal = ExOrdinals[i];
return(RVA(BaseAddress, ExFunctions[Ordinal]));
}
Ordinal = ExOrdinals[mid];
return(RVA(BaseAddress, ExFunctions[Ordinal]));
}
else if (res > 0)
{
maxn = mid - 1;
}
else
{
minn = mid + 1;
}
}
/*
* Fall back on a linear search
*/
DbgPrint("LdrGetExportByName() = failed to find %s\n",SymbolName);
return NULL;
DbgPrint("LDR: Falling back on a linear search of export table\n");
for (i = 0; i < ExportDir->NumberOfFunctions; i++)
{
ExName = RVA(BaseAddress, ExNames[i]);
if (strcmp(ExName,SymbolName) == 0)
{
Ordinal = ExOrdinals[i];
return(RVA(BaseAddress, ExFunctions[Ordinal]));
}
}
DbgPrint("LdrGetExportByName() = failed to find %s\n",SymbolName);
return NULL;
}
@ -1016,12 +1020,13 @@ PEPFUNC LdrPEStartup (PVOID ImageBase,
*/
if (ImageBase != (PVOID) NTHeaders->OptionalHeader.ImageBase)
{
Status = LdrPerformRelocations(NTHeaders, ImageBase);
if (!NT_SUCCESS(Status))
{
DbgPrint("LdrPerformRelocations() failed\n");
return NULL;
}
DbgPrint("LDR: Performing relocations\n");
Status = LdrPerformRelocations(NTHeaders, ImageBase);
if (!NT_SUCCESS(Status))
{
DbgPrint("LdrPerformRelocations() failed\n");
return NULL;
}
}
/*