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Move EnsureReadable() and co. to top of source file.
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@ -113,6 +113,146 @@ extern "C" typedef BOOL (WINAPI *t_GetLogicalProcessorInformationEx)( LOGICAL_PR
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namespace tracy
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{
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#ifdef __ANDROID__
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// Implementation helpers of EnsureReadable(address).
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// This is so far only needed on Android, where it is common for libraries to be mapped
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// with only executable, not readable, permissions. Typical example (line from /proc/self/maps):
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/*
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746b63b000-746b6dc000 --xp 00042000 07:48 35 /apex/com.android.runtime/lib64/bionic/libc.so
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*/
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// See https://github.com/wolfpld/tracy/issues/125 .
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// To work around this, we parse /proc/self/maps and we use mprotect to set read permissions
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// on any mappings that contain symbols addresses hit by HandleSymbolCodeQuery.
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namespace {
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// Holds some information about a single memory mapping.
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struct MappingInfo {
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// Start of address range. Inclusive.
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uintptr_t start_address;
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// End of address range. Exclusive, so the mapping is the half-open interval
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// [start, end) and its length in bytes is `end - start`. As in /proc/self/maps.
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uintptr_t end_address;
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// Read/Write/Executable permissions.
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bool perm_r, perm_w, perm_x;
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};
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} // anonymous namespace
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// Internal implementation helper for LookUpMapping(address).
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//
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// Parses /proc/self/maps returning a vector<MappingInfo>.
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// /proc/self/maps is assumed to be sorted by ascending address, so the resulting
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// vector is sorted by ascending address too.
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static std::vector<MappingInfo> ParseMappings()
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{
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std::vector<MappingInfo> result;
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FILE* file = fopen( "/proc/self/maps", "r" );
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if( !file ) return result;
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char line[1024];
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while( fgets( line, sizeof( line ), file ) )
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{
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uintptr_t start_addr;
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uintptr_t end_addr;
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if( sscanf( line, "%lx-%lx", &start_addr, &end_addr ) != 2 ) continue;
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char* first_space = strchr( line, ' ' );
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if( !first_space ) continue;
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char* perm = first_space + 1;
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char* second_space = strchr( perm, ' ' );
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if( !second_space || second_space - perm != 4 ) continue;
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result.emplace_back();
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auto& mapping = result.back();
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mapping.start_address = start_addr;
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mapping.end_address = end_addr;
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mapping.perm_r = perm[0] == 'r';
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mapping.perm_w = perm[1] == 'w';
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mapping.perm_x = perm[2] == 'x';
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}
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fclose( file );
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return result;
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}
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// Internal implementation helper for LookUpMapping(address).
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//
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// Takes as input an `address` and a known vector `mappings`, assumed to be
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// sorted by increasing addresses, as /proc/self/maps seems to be.
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// Returns a pointer to the MappingInfo describing the mapping that this
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// address belongs to, or nullptr if the address isn't in `mappings`.
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static MappingInfo* LookUpMapping(std::vector<MappingInfo>& mappings, uintptr_t address)
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{
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// Comparison function for std::lower_bound. Returns true if all addresses in `m1`
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// are lower than `addr`.
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auto Compare = []( const MappingInfo& m1, uintptr_t addr ) {
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// '<=' because the address ranges are half-open intervals, [start, end).
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return m1.end_address <= addr;
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};
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auto iter = std::lower_bound( mappings.begin(), mappings.end(), address, Compare );
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if( iter == mappings.end() || iter->start_address > address) {
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return nullptr;
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}
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return &*iter;
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}
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// Internal implementation helper for EnsureReadable(address).
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//
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// Takes as input an `address` and returns a pointer to a MappingInfo
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// describing the mapping that this address belongs to, or nullptr if
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// the address isn't in any known mapping.
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//
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// This function is stateful and not reentrant (assumes to be called from
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// only one thread). It holds a vector of mappings parsed from /proc/self/maps.
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//
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// Attempts to react to mappings changes by re-parsing /proc/self/maps.
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static MappingInfo* LookUpMapping(uintptr_t address)
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{
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// Static state managed by this function. Not constant, we mutate that state as
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// we turn some mappings readable. Initially parsed once here, updated as needed below.
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static std::vector<MappingInfo> s_mappings = ParseMappings();
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MappingInfo* mapping = LookUpMapping( s_mappings, address );
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if( mapping ) return mapping;
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// This address isn't in any known mapping. Try parsing again, maybe
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// mappings changed.
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s_mappings = ParseMappings();
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return LookUpMapping( s_mappings, address );
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}
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// Internal implementation helper for EnsureReadable(address).
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//
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// Attempts to make the specified `mapping` readable if it isn't already.
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// Returns true if and only if the mapping is readable.
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static bool EnsureReadable( MappingInfo& mapping )
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{
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if( mapping.perm_r )
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{
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// The mapping is already readable.
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return true;
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}
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int prot = PROT_READ;
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if( mapping.perm_w ) prot |= PROT_WRITE;
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if( mapping.perm_x ) prot |= PROT_EXEC;
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if( mprotect( reinterpret_cast<void*>( mapping.start_address ),
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mapping.end_address - mapping.start_address, prot ) == -1 )
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{
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// Failed to make the mapping readable. Shouldn't happen, hasn't
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// been observed yet. If it happened in practice, we should consider
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// adding a bool to MappingInfo to track this to avoid retrying mprotect
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// everytime on such mappings.
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return false;
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}
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// The mapping is now readable. Update `mapping` so the next call will be fast.
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mapping.perm_r = true;
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return true;
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}
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// Attempts to set the read permission on the entire mapping containing the
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// specified address. Returns true if and only if the mapping is now readable.
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static bool EnsureReadable( uintptr_t address )
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{
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MappingInfo* mapping = LookUpMapping(address);
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return mapping && EnsureReadable( *mapping );
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}
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#endif // defined __ANDROID__
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#ifndef TRACY_DELAYED_INIT
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struct InitTimeWrapper
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@ -3228,146 +3368,6 @@ void Profiler::HandleParameter( uint64_t payload )
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AckServerQuery();
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}
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#ifdef __ANDROID__
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// Implementation helpers of EnsureReadable(address).
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// This is so far only needed on Android, where it is common for libraries to be mapped
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// with only executable, not readable, permissions. Typical example (line from /proc/self/maps):
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/*
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746b63b000-746b6dc000 --xp 00042000 07:48 35 /apex/com.android.runtime/lib64/bionic/libc.so
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*/
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// See https://github.com/wolfpld/tracy/issues/125 .
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// To work around this, we parse /proc/self/maps and we use mprotect to set read permissions
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// on any mappings that contain symbols addresses hit by HandleSymbolCodeQuery.
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namespace {
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// Holds some information about a single memory mapping.
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struct MappingInfo {
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// Start of address range. Inclusive.
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uintptr_t start_address;
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// End of address range. Exclusive, so the mapping is the half-open interval
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// [start, end) and its length in bytes is `end - start`. As in /proc/self/maps.
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uintptr_t end_address;
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// Read/Write/Executable permissions.
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bool perm_r, perm_w, perm_x;
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};
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} // anonymous namespace
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// Internal implementation helper for LookUpMapping(address).
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//
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// Parses /proc/self/maps returning a vector<MappingInfo>.
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// /proc/self/maps is assumed to be sorted by ascending address, so the resulting
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// vector is sorted by ascending address too.
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static std::vector<MappingInfo> ParseMappings()
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{
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std::vector<MappingInfo> result;
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FILE* file = fopen( "/proc/self/maps", "r" );
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if( !file ) return result;
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char line[1024];
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while( fgets( line, sizeof( line ), file ) )
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{
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uintptr_t start_addr;
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uintptr_t end_addr;
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if( sscanf( line, "%lx-%lx", &start_addr, &end_addr ) != 2 ) continue;
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char* first_space = strchr( line, ' ' );
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if( !first_space ) continue;
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char* perm = first_space + 1;
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char* second_space = strchr( perm, ' ' );
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if( !second_space || second_space - perm != 4 ) continue;
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result.emplace_back();
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auto& mapping = result.back();
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mapping.start_address = start_addr;
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mapping.end_address = end_addr;
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mapping.perm_r = perm[0] == 'r';
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mapping.perm_w = perm[1] == 'w';
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mapping.perm_x = perm[2] == 'x';
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}
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fclose( file );
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return result;
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}
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// Internal implementation helper for LookUpMapping(address).
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//
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// Takes as input an `address` and a known vector `mappings`, assumed to be
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// sorted by increasing addresses, as /proc/self/maps seems to be.
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// Returns a pointer to the MappingInfo describing the mapping that this
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// address belongs to, or nullptr if the address isn't in `mappings`.
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static MappingInfo* LookUpMapping(std::vector<MappingInfo>& mappings, uintptr_t address)
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{
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// Comparison function for std::lower_bound. Returns true if all addresses in `m1`
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// are lower than `addr`.
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auto Compare = []( const MappingInfo& m1, uintptr_t addr ) {
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// '<=' because the address ranges are half-open intervals, [start, end).
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return m1.end_address <= addr;
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};
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auto iter = std::lower_bound( mappings.begin(), mappings.end(), address, Compare );
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if( iter == mappings.end() || iter->start_address > address) {
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return nullptr;
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}
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return &*iter;
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}
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// Internal implementation helper for EnsureReadable(address).
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//
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// Takes as input an `address` and returns a pointer to a MappingInfo
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// describing the mapping that this address belongs to, or nullptr if
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// the address isn't in any known mapping.
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//
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// This function is stateful and not reentrant (assumes to be called from
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// only one thread). It holds a vector of mappings parsed from /proc/self/maps.
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//
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// Attempts to react to mappings changes by re-parsing /proc/self/maps.
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static MappingInfo* LookUpMapping(uintptr_t address)
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{
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// Static state managed by this function. Not constant, we mutate that state as
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// we turn some mappings readable. Initially parsed once here, updated as needed below.
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static std::vector<MappingInfo> s_mappings = ParseMappings();
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MappingInfo* mapping = LookUpMapping( s_mappings, address );
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if( mapping ) return mapping;
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// This address isn't in any known mapping. Try parsing again, maybe
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// mappings changed.
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s_mappings = ParseMappings();
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return LookUpMapping( s_mappings, address );
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}
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// Internal implementation helper for EnsureReadable(address).
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//
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// Attempts to make the specified `mapping` readable if it isn't already.
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// Returns true if and only if the mapping is readable.
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static bool EnsureReadable( MappingInfo& mapping )
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{
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if( mapping.perm_r )
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{
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// The mapping is already readable.
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return true;
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}
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int prot = PROT_READ;
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if( mapping.perm_w ) prot |= PROT_WRITE;
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if( mapping.perm_x ) prot |= PROT_EXEC;
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if( mprotect( reinterpret_cast<void*>( mapping.start_address ),
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mapping.end_address - mapping.start_address, prot ) == -1 )
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{
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// Failed to make the mapping readable. Shouldn't happen, hasn't
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// been observed yet. If it happened in practice, we should consider
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// adding a bool to MappingInfo to track this to avoid retrying mprotect
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// everytime on such mappings.
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return false;
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}
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// The mapping is now readable. Update `mapping` so the next call will be fast.
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mapping.perm_r = true;
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return true;
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}
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// Attempts to set the read permission on the entire mapping containing the
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// specified address. Returns true if and only if the mapping is now readable.
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static bool EnsureReadable( uintptr_t address )
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{
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MappingInfo* mapping = LookUpMapping(address);
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return mapping && EnsureReadable( *mapping );
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}
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#endif // defined __ANDROID__
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void Profiler::HandleSymbolQuery( uint64_t symbol )
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{
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#ifdef TRACY_HAS_CALLSTACK
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