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8225636: SA can't handle prelinked libraries

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Reviewed-by: sspitsyn, cjplummer
This commit is contained in:
Yasumasa Suenaga 2019-06-18 10:54:00 +09:00
parent 5b21004fe0
commit f37c24999d
1 changed files with 51 additions and 0 deletions

51
src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c

@ -839,8 +839,51 @@ static bool read_exec_segments(struct ps_prochandle* ph, ELF_EHDR* exec_ehdr) {
#define LD_BASE_OFFSET offsetof(struct r_debug, r_ldbase)
#define LINK_MAP_ADDR_OFFSET offsetof(struct link_map, l_addr)
#define LINK_MAP_NAME_OFFSET offsetof(struct link_map, l_name)
#define LINK_MAP_LD_OFFSET offsetof(struct link_map, l_ld)
#define LINK_MAP_NEXT_OFFSET offsetof(struct link_map, l_next)
// Calculate the load address of shared library
// on prelink-enabled environment.
//
// In case of GDB, it would be calculated by offset of link_map.l_ld
// and the address of .dynamic section.
// See GDB implementation: lm_addr_check @ solib-svr4.c
static uintptr_t calc_prelinked_load_address(struct ps_prochandle* ph, int lib_fd, ELF_EHDR* elf_ehdr, uintptr_t link_map_addr) {
ELF_PHDR *phbuf;
uintptr_t lib_ld;
uintptr_t lib_dyn_addr = 0L;
uintptr_t load_addr;
int i;
phbuf = read_program_header_table(lib_fd, elf_ehdr);
if (phbuf == NULL) {
print_debug("can't read program header of shared object\n");
return 0L;
}
// Get the address of .dynamic section from shared library.
for (i = 0; i < elf_ehdr->e_phnum; i++) {
if (phbuf[i].p_type == PT_DYNAMIC) {
lib_dyn_addr = phbuf[i].p_vaddr;
break;
}
}
free(phbuf);
if (ps_pdread(ph, (psaddr_t)link_map_addr + LINK_MAP_LD_OFFSET,
&lib_ld, sizeof(uintptr_t)) != PS_OK) {
print_debug("can't read address of dynamic section in shared object\n");
return 0L;
}
// Return the load address which is calculated by the address of .dynamic
// and link_map.l_ld .
load_addr = lib_ld - lib_dyn_addr;
print_debug("lib_ld = 0x%lx, lib_dyn_addr = 0x%lx -> lib_base_diff = 0x%lx\n", lib_ld, lib_dyn_addr, load_addr);
return load_addr;
}
// read shared library info from runtime linker's data structures.
// This work is done by librtlb_db in Solaris
static bool read_shared_lib_info(struct ps_prochandle* ph) {
@ -942,6 +985,14 @@ static bool read_shared_lib_info(struct ps_prochandle* ph) {
// continue with other libraries...
} else {
if (read_elf_header(lib_fd, &elf_ehdr)) {
if (lib_base_diff == 0x0L) {
lib_base_diff = calc_prelinked_load_address(ph, lib_fd, &elf_ehdr, link_map_addr);
if (lib_base_diff == 0x0L) {
close(lib_fd);
return false;
}
}
lib_base = lib_base_diff + find_base_address(lib_fd, &elf_ehdr);
print_debug("reading library %s @ 0x%lx [ 0x%lx ]\n",
lib_name, lib_base, lib_base_diff);