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Fix IPS patching

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- Fix crash on applying IPS patch
- Make IPS offset rewriting work right
This commit is contained in:
Ilari Liusvaara 2011-12-12 18:21:09 +02:00
parent b8e236972a
commit 993eeb20d3
1 changed files with 23 additions and 14 deletions
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37
src/core/patchrom.cpp
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@ -80,9 +80,9 @@ namespace
if(patch.size() < roffset + 3)
throw std::runtime_error("Patch incomplete");
uint32_t a, b, c;
a = patch[roffset + 0];
b = patch[roffset + 1];
c = patch[roffset + 2];
a = static_cast<uint8_t>(patch[roffset + 0]);
b = static_cast<uint8_t>(patch[roffset + 1]);
c = static_cast<uint8_t>(patch[roffset + 2]);
uint32_t rec_off = a * 65536 + b * 256 + c;
if(rec_off == 0x454F46) {
//EOF.
@ -91,16 +91,16 @@ namespace
}
if(patch.size() < roffset + 5)
throw std::runtime_error("Patch incomplete");
a = patch[roffset + 3];
b = patch[roffset + 4];
a = static_cast<uint8_t>(patch[roffset + 3]);
b = static_cast<uint8_t>(patch[roffset + 4]);
uint32_t rec_size = a * 256 + b;
uint32_t rec_rlesize = 0;
uint32_t rec_rawsize = 0;
if(!rec_size) {
if(patch.size() < roffset + 8)
throw std::runtime_error("Patch incomplete");
a = patch[roffset + 5];
b = patch[roffset + 6];
a = static_cast<uint8_t>(patch[roffset + 5]);
b = static_cast<uint8_t>(patch[roffset + 6]);
rec_rlesize = a * 256 + b;
rec_rawsize = 8;
} else
@ -110,15 +110,21 @@ namespace
throw std::runtime_error("Offset exceeds IPS 16MiB limit");
if(rec_noff < 0) {
//This operation needs to clip the start as it is out of bounds.
while(rec_size > 0 && rec_noff + rec_size <= 0) {
rec_noff++;
rec_size--;
if(rec_size) {
if(rec_size > -rec_noff) {
rec_noff = 0;
rec_size -= -rec_noff;
} else
rec_size = 0;
}
while(rec_rlesize > 0 && rec_noff + rec_rlesize <= 0) {
rec_noff++;
rec_rlesize--;
if(rec_rlesize) {
if(rec_rlesize > -rec_noff) {
rec_noff = 0;
rec_rlesize -= -rec_noff;
} else
rec_rlesize = 0;
}
if(rec_noff + rec_size + rec_rlesize <= 0)
if(!rec_size && !rec_rlesize)
return std::make_pair(0, rec_rawsize); //Completely out of bounds.
}
//Write the modified record.
@ -172,6 +178,9 @@ namespace
std::vector<char> ret;
ret.resize(p.size);
memcpy(&ret[0], p.data, p.size);
//No, these can't be freed.
p.source(NULL, 0);
p.modify(NULL, 0);
return ret;
}
}