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author | Yotam Barnoy | 2009-10-30 12:26:24 +0000 |
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committer | Yotam Barnoy | 2009-10-30 12:26:24 +0000 |
commit | 272cc757152e0fc8f2c1821871c8f108f05c20ce (patch) | |
tree | ea538710650e526036135e3cca28fc8ac1edc64c /backends | |
parent | 0cecbffb608bc1de8a908092ff083d58d3afcc59 (diff) | |
download | scummvm-rg350-272cc757152e0fc8f2c1821871c8f108f05c20ce.tar.gz scummvm-rg350-272cc757152e0fc8f2c1821871c8f108f05c20ce.tar.bz2 scummvm-rg350-272cc757152e0fc8f2c1821871c8f108f05c20ce.zip |
PSP: Fixed serious issue in plugins due to way gcc sometimes works. Was only observable in Kyra engine but potentially applicable to all
svn-id: r45535
Diffstat (limited to 'backends')
-rw-r--r-- | backends/platform/psp/psploader.cpp | 47 |
1 files changed, 36 insertions, 11 deletions
diff --git a/backends/platform/psp/psploader.cpp b/backends/platform/psp/psploader.cpp index 227a2e43cc..e3909d536b 100644 --- a/backends/platform/psp/psploader.cpp +++ b/backends/platform/psp/psploader.cpp @@ -112,8 +112,10 @@ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void * unsigned int *lastTarget = 0; // For processing hi16 when lo16 arrives unsigned int relocation = 0; - int debugRelocs[10] = {0}; // For debugging + int debugRelocs[10] = {0}; // For debugging int extendedHi16 = 0; // Count extended hi16 treatments + Elf32_Addr lastHiSymVal = 0; + bool hi16InShorts = false; #define DEBUG_NUM 2 @@ -132,11 +134,13 @@ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void * case R_MIPS_HI16: // Absolute addressing. if (sym->st_shndx < SHN_LOPROC && // Only shift for plugin section (ie. has a real section index) - firstHi16 < 0) { // Only process first in block of HI16s + firstHi16 < 0 ) { // Only process first in block of HI16s firstHi16 = i; // Keep the first Hi16 we saw seenHi16 = true; ahl = (*target & 0xffff) << 16; // Take lower 16 bits shifted up - + + lastHiSymVal = sym->st_value; + hi16InShorts = (ShortsMan.inGeneralSegment((char *)sym->st_value)); // Fix for problem with switching btw segments if (debugRelocs[0]++ < DEBUG_NUM) // Print only a set number DBG("R_MIPS_HI16: i=%d, offset=%x, ahl = %x, target = %x\n", i, rel[i].r_offset, ahl, *target); @@ -145,17 +149,34 @@ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void * case R_MIPS_LO16: // Absolute addressing. Needs a HI16 to come before it if (sym->st_shndx < SHN_LOPROC) { // Only shift for plugin section. (ie. has a real section index) - if (!seenHi16) { // We MUST have seen HI16 first + if (!seenHi16) { // We MUST have seen HI16 first seterror("R_MIPS_LO16 w/o preceding R_MIPS_HI16 at relocation %d!\n", i); free(rel); return false; } - + + // Fix: bug in gcc makes LO16s connect to wrong HI16s sometimes (shorts and regular segment) + // Note that we can check the entire shorts segment because the executable's shorts don't belong to this plugin section + // and will be screened out above + bool lo16InShorts = ShortsMan.inGeneralSegment((char *)sym->st_value); + + // Correct the bug by getting the proper value in ahl (taken from the current symbol) + if ((hi16InShorts && !lo16InShorts) || (!hi16InShorts && lo16InShorts)) { + ahl -= (lastHiSymVal & 0xffff0000); // We assume gcc meant the same offset + ahl += (sym->st_value & 0xffff0000); + } + ahl &= 0xffff0000; // Clean lower 16 bits for repeated LO16s a = *target & 0xffff; // Take lower 16 bits of the target - a = (a << 16) >> 16; // Sign extend them + a = (a << 16) >> 16; // Sign extend them ahl += a; // Add lower 16 bits. AHL is now complete - relocation = ahl + (Elf32_Addr)_segment; // Add in the new offset for the segment + + // Fix: we can have LO16 access to the short segment sometimes + if (lo16InShorts) { + relocation = ahl + _shortsSegment->getOffset(); // Add in the short segment offset + } + else // It's in the regular segment + relocation = ahl + (Elf32_Addr)_segment; // Add in the new offset for the segment if (firstHi16 >= 0) { // We haven't treated the HI16s yet so do it now for (int j = firstHi16; j < i; j++) { @@ -177,13 +198,13 @@ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void * if (debugRelocs[1]++ < DEBUG_NUM) DBG("R_MIPS_LO16: i=%d, offset=%x, a=%x, ahl = %x, lastTarget = %x, origt = %x, target = %x\n", i, rel[i].r_offset, a, ahl, *lastTarget, origTarget, *target); - if (ahl & 0x8000 && debugRelocs[2]++ < DEBUG_NUM) - DBG("R_MIPS_LO16: i=%d, offset=%x, a=%x, ahl = %x, lastTarget = %x, origt = %x, target = %x\n", + if (lo16InShorts && debugRelocs[2]++ < DEBUG_NUM) + DBG("R_MIPS_LO16s: i=%d, offset=%x, a=%x, ahl = %x, lastTarget = %x, origt = %x, target = %x\n", i, rel[i].r_offset, a, ahl, *lastTarget, origTarget, *target); } break; - case R_MIPS_26: // Absolute addressing + case R_MIPS_26: // Absolute addressing (for jumps and branches only) 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 @@ -222,7 +243,11 @@ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void * case R_MIPS_32: // Absolute addressing if (sym->st_shndx < SHN_LOPROC) { // Only shift for plugin section. a = *target; // Get full 32 bits of addend - relocation = a + (Elf32_Addr)_segment; // Shift + + 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)_segment; // Shift by main offset *target = relocation; if (debugRelocs[6]++ < DEBUG_NUM) |