libretro/scummvm
1
0
Fork 0
mirror of https://github.com/libretro/scummvm.git synced 2025-04-02 23:01:42 +00:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

PLUGINS: fixed issue with R_MIPS_32 relocations

Browse Source 
Caused crash in some games. The problem was referring to the right segment. R_MIPS_32 relocations can be found in the Shorts segment, but still need to refer to the main segment if the symbol is found there.

svn-id: r52750
This commit is contained in:
Yotam Barnoy 2010-09-16 17:37:54 +00:00
parent 09cb941690
commit 8df4278ba8
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
backends/plugins/elf/mips-loader.cpp
View File

@ -54,6 +54,8 @@ bool MIPSDLObject::relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment)
debug(2, "elfloader: Loaded relocation table. %d entries. base address=%p", cnt, relSegment);
Elf32_Addr adjustedMainSegment = Elf32_Addr(_segment) - _segmentVMA; // adjust for VMA offset
bool seenHi16 = false; // For treating HI/LO16 commands
int32 firstHi16 = -1; // Mark the point of the first hi16 seen
Elf32_Addr ahl = 0; // Calculated addend
@ -121,7 +123,7 @@ bool MIPSDLObject::relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment)
if (lo16InShorts)
relocation = ahl + _shortsSegment->getOffset(); // Add in the short segment offset
else // It's in the regular segment
relocation = ahl + Elf32_Addr(relSegment); // Add in the new offset for the segment
relocation = ahl + adjustedMainSegment; // Add in the new offset for the segment
if (firstHi16 >= 0) { // We haven't treated the HI16s yet so do it now
for (uint32 j = firstHi16; j < i; j++) {
@ -159,7 +161,7 @@ bool MIPSDLObject::relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment)
if (sym->st_shndx < SHN_LOPROC) { // Only relocate for main segment
a = *target & 0x03ffffff; // Get 26 bits' worth of the addend
a = (a << 6) >> 6; // Sign extend a
relocation = ((a << 2) + Elf32_Addr(relSegment)) >> 2; // a already points to the target. Subtract our offset
relocation = ((a << 2) + adjustedMainSegment) >> 2; // a already points to the target. Add our offset
*target &= 0xfc000000; // Clean lower 26 target bits
*target |= (relocation & 0x03ffffff);
@ -201,7 +203,7 @@ bool MIPSDLObject::relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment)
if (ShortsMan.inGeneralSegment((char *)sym->st_value)) // Check if we're in the shorts segment
relocation = a + _shortsSegment->getOffset(); // Shift by shorts offset
else // We're in the main section
relocation = a + Elf32_Addr(relSegment); // Shift by main offset
relocation = a + adjustedMainSegment; // Shift by main offset
*target = relocation;