Fix lines table overflow detection segfault #101
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Could you write a few lines to explain what this patch does? And where the values |
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I think the title explains it pretty well. You're currently reading unmapped memory to find where the lines table ends, and (wrongly) expecting zeroes when you do (instead of garbage or an outright crash). The values have to do with AMX structure. I honestly do not remember. This is tested, working, and most importantly correct (at least more than the original code...). |
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OK, that's great, thanks |
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@Cheaterman Thanks for submitting this PR. Please check my comments if you still want to have this merged.
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| unsigned int lines_overflow_count = 0; | ||
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| while(biggest_possible_size < dbghdr.size) { |
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We need to convert the byte order via amx_AlignXXX() calls like in the original AMX implementation to preserve support for Big Endian systems. Who knows what happens in the future, maybe someone ends up using this on ARM. So I'd like this to stick to the existing conventions that the rest of the AMX implementation adheres to.
| @@ -123,14 +123,14 @@ typedef struct tagAMX_DBG_STATE { | |||
| } AMX_DBG_STATE PACKED; | |||
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| typedef struct tagAMX_DBG { | |||
| AMX_DBG_HDR _FAR *hdr PACKED; /* points to the AMX_DBG header */ | |||
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These whitespace changes are not relevant to the patch. Please revert.
| } /* while */ | ||
| unsigned int biggest_possible_size = ( | ||
| sizeof(AMX_DBG_HDR) | ||
| + dbghdr.files * (sizeof(AMX_DBG_FILE) + 33) |
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It is not clear what 33 stands for. I for one don't remember what it means. Can you put this in a constant (pre-processor #define to be exact) or infer it from some sizeof arithmetic it it corresponds to the size of some structures?
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| ptr += ( | ||
| dbghdr.lines * sizeof(AMX_DBG_LINE) | ||
| + lines_overflow_count * 0x10000 * sizeof(AMX_DBG_LINE) |
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Please use a named constant like (IN16_MAX+1) instead of 0x10000
| #endif | ||
| ptr += ((uint32_t)dbghdr.lines + 1) * sizeof(AMX_DBG_LINE); | ||
| } /* while */ | ||
| unsigned int biggest_possible_size = ( |
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The source code of AMX is written in ANSI C, which does not allow declaring variables after statements. Let's stick to that convention to not introduce compilation issues and for consistency sake.
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Ended up implementing it a little differently in master. |
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