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From: Adhemerval Zanella <azanella@sourceware.org>
To: glibc-cvs@sourceware.org
Subject: [glibc/azanella/ld-audit-fixes] elf: Add _dl_audit_symbind_alt and _dl_audit_symbind
Date: Wed, 4 Aug 2021 17:47:39 +0000 (GMT) [thread overview]
Message-ID: <20210804174739.0C0E6386482B@sourceware.org> (raw)
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=4038a855a9db87c33f8f8a657f30b363966d3919
commit 4038a855a9db87c33f8f8a657f30b363966d3919
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Tue Jul 20 15:58:35 2021 -0300
elf: Add _dl_audit_symbind_alt and _dl_audit_symbind
It consolidates the code required to call la_symbind{32,64}() audit
callback.
Diff:
---
elf/Versions | 1 +
elf/dl-audit.c | 122 +++++++++++++++++++++++++++++++++++++++++++++
elf/dl-runtime.c | 77 ----------------------------
elf/dl-sym-post.h | 47 +----------------
sysdeps/generic/ldsodefs.h | 6 +++
5 files changed, 130 insertions(+), 123 deletions(-)
diff --git a/elf/Versions b/elf/Versions
index 775aab62af..25e91339b5 100644
--- a/elf/Versions
+++ b/elf/Versions
@@ -55,6 +55,7 @@ ld {
_dl_argv; _dl_find_dso_for_object; _dl_get_tls_static_info;
_dl_deallocate_tls; _dl_make_stack_executable;
_dl_rtld_di_serinfo; _dl_starting_up; _dl_fatal_printf;
+ _dl_audit_symbind_alt;
_rtld_global; _rtld_global_ro;
# Only here for gdb while a better method is developed.
diff --git a/elf/dl-audit.c b/elf/dl-audit.c
index ef34ff761c..8e4c65fdaf 100644
--- a/elf/dl-audit.c
+++ b/elf/dl-audit.c
@@ -16,6 +16,7 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <assert.h>
#include <ldsodefs.h>
#ifdef SHARED
@@ -120,4 +121,125 @@ _dl_audit_objclose (struct link_map *l, Lmid_t nsid)
afct = afct->next;
}
}
+
+void
+_dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref, void **value,
+ lookup_t result)
+{
+ if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0)
+ return;
+
+ const char *strtab = (const char *) D_PTR (result, l_info[DT_STRTAB]);
+ /* Compute index of the symbol entry in the symbol table of the DSO with
+ the definition. */
+ unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result, l_info[DT_SYMTAB]));
+
+ unsigned int altvalue = 0;
+ /* Synthesize a symbol record where the st_value field is the result. */
+ ElfW(Sym) sym = *ref;
+ sym.st_value = (ElfW(Addr)) *value;
+
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ struct auditstate *match_audit = link_map_audit_state (l, cnt);
+ struct auditstate *result_audit = link_map_audit_state (result, cnt);
+ if (afct->symbind != NULL
+ && ((match_audit->bindflags & LA_FLG_BINDFROM) != 0
+ || ((result_audit->bindflags & LA_FLG_BINDTO)
+ != 0)))
+ {
+ unsigned int flags = altvalue | LA_SYMB_DLSYM;
+ uintptr_t new_value = afct->symbind (&sym, ndx,
+ &match_audit->cookie,
+ &result_audit->cookie,
+ &flags, strtab + ref->st_name);
+ if (new_value != (uintptr_t) sym.st_value)
+ {
+ altvalue = LA_SYMB_ALTVALUE;
+ sym.st_value = new_value;
+ }
+
+ afct = afct->next;
+ }
+
+ *value = (void *) sym.st_value;
+ }
+}
+rtld_hidden_def (_dl_audit_symbind_alt)
+
+void
+_dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
+ const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,
+ lookup_t result)
+{
+ reloc_result->bound = result;
+ /* Compute index of the symbol entry in the symbol table of the DSO with the
+ definition. */
+ reloc_result->boundndx = (defsym - (ElfW(Sym) *) D_PTR (result,
+ l_info[DT_SYMTAB]));
+
+ if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0)
+ {
+ /* Set all bits since this symbol binding is not interesting. */
+ reloc_result->enterexit = (1u << DL_NNS) - 1;
+ return;
+ }
+
+ /* Synthesize a symbol record where the st_value field is the result. */
+ ElfW(Sym) sym = *defsym;
+ sym.st_value = DL_FIXUP_VALUE_ADDR (*value);
+
+ /* Keep track whether there is any interest in tracing the call in the lower
+ two bits. */
+ assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8);
+ assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3);
+ reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT;
+
+ const char *strtab2 = (const void *) D_PTR (result, l_info[DT_STRTAB]);
+
+ unsigned int flags = 0;
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ /* XXX Check whether both DSOs must request action or only one */
+ struct auditstate *l_state = link_map_audit_state (l, cnt);
+ struct auditstate *result_state = link_map_audit_state (result, cnt);
+ if ((l_state->bindflags & LA_FLG_BINDFROM) != 0
+ && (result_state->bindflags & LA_FLG_BINDTO) != 0)
+ {
+ if (afct->symbind != NULL)
+ {
+ uintptr_t new_value = afct->symbind (&sym,
+ reloc_result->boundndx,
+ &l_state->cookie,
+ &result_state->cookie,
+ &flags,
+ strtab2 + defsym->st_name);
+ if (new_value != (uintptr_t) sym.st_value)
+ {
+ flags |= LA_SYMB_ALTVALUE;
+ sym.st_value = new_value;
+ }
+ }
+
+ /* Remember the results for every audit library and store a summary
+ in the first two bits. */
+ reloc_result->enterexit &= flags & (LA_SYMB_NOPLTENTER
+ | LA_SYMB_NOPLTEXIT);
+ reloc_result->enterexit |= ((flags & (LA_SYMB_NOPLTENTER
+ | LA_SYMB_NOPLTEXIT))
+ << ((cnt + 1) * 2));
+ }
+ else
+ /* If the bind flags say this auditor is not interested, set the bits
+ manually. */
+ reloc_result->enterexit |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)
+ << ((cnt + 1) * 2));
+ afct = afct->next;
+ }
+
+ reloc_result->flags = flags;
+ *value = DL_FIXUP_ADDR_VALUE (sym.st_value);
+}
#endif
diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
index 29031099f5..680e66a6d6 100644
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -43,83 +43,6 @@
# define ARCH_FIXUP_ATTRIBUTE
#endif
-#ifdef SHARED
-static void
-_dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
- const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,
- lookup_t result)
-{
- reloc_result->bound = result;
- /* Compute index of the symbol entry in the symbol table of the DSO with the
- definition. */
- reloc_result->boundndx = (defsym - (ElfW(Sym) *) D_PTR (result,
- l_info[DT_SYMTAB]));
-
- if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0)
- {
- /* Set all bits since this symbol binding is not interesting. */
- reloc_result->enterexit = (1u << DL_NNS) - 1;
- return;
- }
-
- /* Synthesize a symbol record where the st_value field is the result. */
- ElfW(Sym) sym = *defsym;
- sym.st_value = DL_FIXUP_VALUE_ADDR (*value);
-
- /* Keep track whether there is any interest in tracing the call in the lower
- two bits. */
- assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8);
- assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3);
- reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT;
-
- const char *strtab2 = (const void *) D_PTR (result, l_info[DT_STRTAB]);
-
- unsigned int flags = 0;
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- /* XXX Check whether both DSOs must request action or only one */
- struct auditstate *l_state = link_map_audit_state (l, cnt);
- struct auditstate *result_state = link_map_audit_state (result, cnt);
-
- if ((l_state->bindflags & LA_FLG_BINDFROM) != 0
- && (result_state->bindflags & LA_FLG_BINDTO) != 0)
- {
- if (afct->symbind != NULL)
- {
- uintptr_t new_value = afct->symbind (&sym,
- reloc_result->boundndx,
- &l_state->cookie,
- &result_state->cookie,
- &flags,
- strtab2 + defsym->st_name);
- if (new_value != (uintptr_t) sym.st_value)
- {
- flags |= LA_SYMB_ALTVALUE;
- sym.st_value = new_value;
- }
- }
-
- /* Remember the results for every audit library and store a summary
- in the first two bits. */
- reloc_result->enterexit &= flags & (LA_SYMB_NOPLTENTER
- | LA_SYMB_NOPLTEXIT);
- reloc_result->enterexit |= ((flags & (LA_SYMB_NOPLTENTER
- | LA_SYMB_NOPLTEXIT))
- << ((cnt + 1) * 2));
- }
- else
- /* If the bind flags say this auditor is not interested, set the bits
- manually. */
- reloc_result->enterexit |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)
- << ((cnt + 1) * 2));
- afct = afct->next;
- }
-
- reloc_result->flags = flags;
- *value = DL_FIXUP_ADDR_VALUE (sym.st_value);
-}
-#endif
/* This function is called through a special trampoline from the PLT the
first time each PLT entry is called. We must perform the relocation
diff --git a/elf/dl-sym-post.h b/elf/dl-sym-post.h
index d68c2d2b1c..a11095d3e8 100644
--- a/elf/dl-sym-post.h
+++ b/elf/dl-sym-post.h
@@ -52,54 +52,9 @@ _dl_sym_post (lookup_t result, const ElfW(Sym) *ref, void *value,
tell us whether further auditing is wanted. */
if (__glibc_unlikely (GLRO(dl_naudit) > 0))
{
- const char *strtab = (const char *) D_PTR (result,
- l_info[DT_STRTAB]);
- /* Compute index of the symbol entry in the symbol table of
- the DSO with the definition. */
- unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result,
- l_info[DT_SYMTAB]));
-
if (match == NULL)
match = _dl_sym_find_caller_link_map (caller);
-
- if ((match->l_audit_any_plt | result->l_audit_any_plt) != 0)
- {
- unsigned int altvalue = 0;
- struct audit_ifaces *afct = GLRO(dl_audit);
- /* Synthesize a symbol record where the st_value field is
- the result. */
- ElfW(Sym) sym = *ref;
- sym.st_value = (ElfW(Addr)) value;
-
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- struct auditstate *match_audit
- = link_map_audit_state (match, cnt);
- struct auditstate *result_audit
- = link_map_audit_state (result, cnt);
- if (afct->symbind != NULL
- && ((match_audit->bindflags & LA_FLG_BINDFROM) != 0
- || ((result_audit->bindflags & LA_FLG_BINDTO)
- != 0)))
- {
- unsigned int flags = altvalue | LA_SYMB_DLSYM;
- uintptr_t new_value
- = afct->symbind (&sym, ndx,
- &match_audit->cookie,
- &result_audit->cookie,
- &flags, strtab + ref->st_name);
- if (new_value != (uintptr_t) sym.st_value)
- {
- altvalue = LA_SYMB_ALTVALUE;
- sym.st_value = new_value;
- }
- }
-
- afct = afct->next;
- }
-
- value = (void *) sym.st_value;
- }
+ _dl_audit_symbind_alt (match, ref, &value, result);
}
#endif
return value;
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 58705d008e..d956cf2235 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1361,6 +1361,12 @@ void _dl_audit_activity_nsid (Lmid_t nsid, int action);
if main mapping of the namespace is a audit modules. */
void _dl_audit_objopen (struct link_map *l, Lmid_t nsid, bool check_audit);
void _dl_audit_objclose (struct link_map *l, Lmid_t nsid);
+void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
+ const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,
+ lookup_t result);
+void _dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref,
+ void **value, lookup_t result);
+rtld_hidden_proto (_dl_audit_symbind_alt)
#endif /* SHARED */
#if PTHREAD_IN_LIBC && defined SHARED
next reply other threads:[~2021-08-04 17:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-04 17:47 Adhemerval Zanella [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-11-16 13:57 Adhemerval Zanella
2021-11-09 18:18 Adhemerval Zanella
2021-09-10 18:26 Adhemerval Zanella
2021-08-04 20:53 Adhemerval Zanella
2021-07-30 19:25 Adhemerval Zanella
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