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Handle RPATH in user program #48

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Handle RPATH in user program #48

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73 changes: 72 additions & 1 deletion src/track/heaptrack_inject.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -176,9 +176,80 @@ struct dlopen
static constexpr auto name = "dlopen";
static constexpr auto original = &::dlopen;

static Dl_serinfo* load_serinfo(const char* module_path) noexcept
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instead of returning an memory allocated serinfo, can't you take that Dl_serinfo * as an out-param, and construct it on the stack of the caller and return bool instead?

{
Dl_serinfo *serinfo = NULL;
Dl_serinfo serinfo_size;
void *module;

module = original(module_path, RTLD_LAZY);
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auto module = original(...);

if (module == NULL) {
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if (!module)

return NULL;
}

int res = dlinfo(module, RTLD_DI_SERINFOSIZE, &serinfo_size);
if (res) {
dlclose(module);
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output an error?

return NULL;
}

serinfo = (Dl_serinfo*) ::malloc(serinfo_size.dls_size);
*serinfo = serinfo_size;
res = dlinfo(module, RTLD_DI_SERINFO, serinfo);
if (res) {
::free(serinfo);
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output an error?

serinfo = NULL;
}
dlclose(module);
return serinfo;
}

static void* hook(const char* filename, int flag) noexcept
{
auto ret = original(filename, flag);
void *ret = NULL;
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please extract this code into a separate function with a descriptive name

bool fallback = false;
if (filename == NULL || filename[0] == '/') {
// absolute path
ret = original(filename, flag);
}
if (!ret) {
// need to respect rpath
// get module info
Dl_info dl_info;
int res = dladdr(__builtin_return_address(0), &dl_info);
if (!res) {
fallback = true;
} else {
Dl_serinfo *serinfo;
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see above: here just do Dl_serinfo serinfo; and then pass &serinfo to the load_serinfo call below?

serinfo = load_serinfo(dl_info.dli_fname);
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otherwise: auto serinfo = load_serinfo(...)

if (serinfo == NULL) {
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if (!serinfo)

fallback = true;
} else {
struct stat file_stat;
char file_path[PATH_MAX];
for (unsigned int i = 0; i < serinfo->dls_cnt; i++) {
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add documentation to explain what this loop does - it seems to stat some files and build some path, can you give some examples for how the path is build?

file_path[0] = 0;
strcat(file_path, serinfo->dls_serpath[i].dls_name);
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strcat is unsafe and can overflow, please use strncat and track buffer size, or can we just use std::string instead?

strcat(file_path, "/");
strcat(file_path, filename);
int res = stat(file_path, &file_stat);
if (res) {
continue;
}
::free(serinfo);
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potentially leaked, has to be freed outside - better use std::unique_ptr if the heap allocation is needed, but best use the stack

// found file
ret = original(file_path, flag);
break;
}
}
}
}

if (!ret && fallback) {
ret = original(filename, flag);
}


if (ret) {
heaptrack_invalidate_module_cache();
overwrite_symbols();
Expand Down