diff options
Diffstat (limited to 'runtime/sym.c')
| -rw-r--r-- | runtime/sym.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/runtime/sym.c b/runtime/sym.c index 1a9e26b2..d7b079d2 100644 --- a/runtime/sym.c +++ b/runtime/sym.c @@ -160,6 +160,66 @@ static const char *_stp_kallsyms_lookup(unsigned long addr, unsigned long *symbo return NULL; } +/* Validate module/kernel based on build-id if there +* The completed case is the following combination: +* Debuginfo Module Kernel +* X X +* has build-id/not unloaded has build-id/not +* loaded && (has build-id/not) +* +* NB: build-id exists only if ld>=2.18 and kernel>= 2.6.23 +*/ +static int _stp_module_check(void) +{ + struct _stp_module *m = NULL; + unsigned long notes_addr, base_addr; + unsigned i,j; + + for (i = 0; i < _stp_num_modules; i++) + { + m = _stp_modules[i]; + if (m->build_id_len > 0 && m->notes_sect != 0) { + dbug_sym(1, "build-id validation [%s]\n", m->name); + + /* notes end address */ + if (!strcmp(m->name, "kernel")) { + notes_addr = m->build_id_offset; + base_addr = _stp_module_relocate("kernel", + "_stext", 0); + } else { + notes_addr = m->notes_sect + m->build_id_offset; + base_addr = m->notes_sect; + } + + /* build-id note payload start address */ + /* XXX: But see https://bugzilla.redhat.com/show_bug.cgi?id=465872; + dwfl_module_build_id was not intended to return the end address. */ + notes_addr -= m->build_id_len; + + if (notes_addr > base_addr) { + for (j = 0; j < m->build_id_len; j++) + { + unsigned char theory, practice; + theory = m->build_id_bits [j]; + practice = ((unsigned char*) notes_addr) [j]; + /* XXX: consider using kread() instead of above. */ + if (theory != practice) + { + printk(KERN_WARNING + "%s: inconsistent %s build-id byte #%d " + "(0x%x [actual] vs. 0x%x [debuginfo])\n", + THIS_MODULE->name, m->name, j, + practice, theory); + break; /* Note just the first mismatch. */ + /* XXX: If it were not for Fedora bug #465873, + we could "return 1;" here to abort the script. */ + } + } + } + } /* end checking */ + } /* end loop */ + return 0; +} /** Print an address symbolically. * @param address The address to lookup. |