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Merge "Add flag that makes linker honor min(p_vaddr)" into mnc-dev

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This commit is contained in:
David Srbecky 2015-06-19 18:25:56 +00:00 committed by Android (Google) Code Review
commit c08c88b5fc
2 changed files with 16 additions and 2 deletions
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10
libc/include/android/dlext.h
View File

@ -73,6 +73,13 @@ enum {
*/
ANDROID_DLEXT_FORCE_LOAD = 0x40,
/* When set, if the minimum p_vaddr of the ELF file's PT_LOAD segments is non-zero,
* the dynamic linker will load it at that address.
*
* This flag is for ART internal use only.
*/
ANDROID_DLEXT_FORCE_FIXED_VADDR = 0x80,
/* Mask of valid bits */
ANDROID_DLEXT_VALID_FLAG_BITS = ANDROID_DLEXT_RESERVED_ADDRESS |
ANDROID_DLEXT_RESERVED_ADDRESS_HINT |
@ -80,7 +87,8 @@ enum {
ANDROID_DLEXT_USE_RELRO |
ANDROID_DLEXT_USE_LIBRARY_FD |
ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET |
ANDROID_DLEXT_FORCE_LOAD,
ANDROID_DLEXT_FORCE_LOAD |
ANDROID_DLEXT_FORCE_FIXED_VADDR,
};
typedef struct {

8
linker/linker_phdr.cpp
View File

@ -316,6 +316,8 @@ bool ElfReader::ReserveAddressSpace(const android_dlextinfo* extinfo) {
void* start;
size_t reserved_size = 0;
bool reserved_hint = true;
// Assume position independent executable by default.
uint8_t* mmap_hint = nullptr;
if (extinfo != nullptr) {
if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS) {
@ -324,6 +326,10 @@ bool ElfReader::ReserveAddressSpace(const android_dlextinfo* extinfo) {
} else if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS_HINT) {
reserved_size = extinfo->reserved_size;
}
if ((extinfo->flags & ANDROID_DLEXT_FORCE_FIXED_VADDR) != 0) {
mmap_hint = addr;
}
}
if (load_size_ > reserved_size) {
@ -333,7 +339,7 @@ bool ElfReader::ReserveAddressSpace(const android_dlextinfo* extinfo) {
return false;
}
int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
start = mmap(nullptr, load_size_, PROT_NONE, mmap_flags, -1, 0);
start = mmap(mmap_hint, load_size_, PROT_NONE, mmap_flags, -1, 0);
if (start == MAP_FAILED) {
DL_ERR("couldn't reserve %zd bytes of address space for \"%s\"", load_size_, name_);
return false;