I filed it to JBS as JDK-8173941.
Yasumasa
On 2017/02/05 23:25, Yasumasa Suenaga wrote:
Hi all,
In modern Linux e.g. Fedora 25, executables are built as DSO for security [1].
java command in OpenJDK which is provided by distribution is also DSO.
However, SA does not work with DSO executables.
I want to propose the fix as below.
------------------------
diff -r a26b9492461b src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c
--- a/src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c Wed Feb 01
17:56:22 2017 -0500
+++ b/src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c Sun Feb 05
23:13:19 2017 +0900
@@ -642,6 +642,9 @@
if (core_handle_prstatus(ph, descdata, notep->n_descsz) != true) {
return false;
}
+ } else if (notep->n_type == NT_FILE) {
+ // Skip "count", "page_size" in NT_FILE
+ memcpy(&ph->core->dynamic_addr, ((long *)descdata) + 2, sizeof(long));
}
p = descdata + ROUNDUP(notep->n_descsz, 4);
}
@@ -832,7 +835,11 @@
// from PT_DYNAMIC we want to read address of first link_map addr
case PT_DYNAMIC: {
- ph->core->dynamic_addr = exec_php->p_vaddr;
+ if (exec_ehdr->e_type == ET_EXEC) {
+ ph->core->dynamic_addr = exec_php->p_vaddr;
+ } else { // ET_DYN
+ ph->core->dynamic_addr += exec_php->p_offset;
+ }
print_debug("address of _DYNAMIC is 0x%lx\n", ph->core->dynamic_addr);
break;
}
@@ -1030,8 +1037,9 @@
goto err;
}
- if (read_elf_header(ph->core->exec_fd, &exec_ehdr) != true ||
exec_ehdr.e_type != ET_EXEC) {
- print_debug("executable file is not a valid ELF ET_EXEC file\n");
+ if (read_elf_header(ph->core->exec_fd, &exec_ehdr) != true ||
+ ((exec_ehdr.e_type != ET_EXEC) && (exec_ehdr.e_type != ET_DYN))) {
+ print_debug("executable file is not a valid ELF file\n");
goto err;
}
------------------------
Currently, OpenJDK 8 in Fedora25 is built as DSO.
So I want to contribute this patch to JDK 8 or later release.
Can I file it to JBS and can send review request?
Thanks,
Yasumasa
[1] https://fedoraproject.org/wiki/Packaging:Guidelines#PIE
