summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorCarlos Eduardo Seo <carlos.seo@arm.com>2022-05-18 00:52:09 +0000
committerSzabolcs Nagy <szabolcs.nagy@arm.com>2022-11-22 14:31:25 +0000
commitf1d4e428354a0b9b04b47508af8592ff9caa516b (patch)
treea00159774128c0c091bba93566be9850e9e1d924
parent4661ab7a69fd30bf29f6dfdb39d76cc5d13c9cc6 (diff)
downloadglibc-f1d4e428354a0b9b04b47508af8592ff9caa516b.tar.gz
TODO(api): cheri: misc: Implement new function getauxptr for CHERI capabilities
New function to return values from the auxiliary vector as capabilities. This is the same as implemented by other C libraries. TODO: agree about exact semantics across libcs
-rw-r--r--include/sys/auxv.h4
-rw-r--r--misc/Versions3
-rw-r--r--misc/getauxval.c33
-rw-r--r--misc/sys/auxv.h4
4 files changed, 44 insertions, 0 deletions
diff --git a/include/sys/auxv.h b/include/sys/auxv.h
index dd0602b08d..0bd40bd835 100644
--- a/include/sys/auxv.h
+++ b/include/sys/auxv.h
@@ -10,4 +10,8 @@ libc_hidden_proto (__getauxval)
_Bool __getauxval2 (unsigned long int type, unsigned long int *result);
libc_hidden_proto (__getauxval2)
+/* Like getauxval, but for Arm Morello capabilities. */
+extern __typeof (getauxptr) __getauxptr;
+libc_hidden_proto (__getauxptr)
+
#endif /* !_ISOMAC */
diff --git a/misc/Versions b/misc/Versions
index d5b348e83a..669a03ffb3 100644
--- a/misc/Versions
+++ b/misc/Versions
@@ -164,6 +164,9 @@ libc {
GLIBC_2.32 {
__libc_single_threaded;
}
+ GLIBC_2.36 {
+ __getauxptr; getauxptr;
+ }
GLIBC_PRIVATE {
__madvise;
__mktemp;
diff --git a/misc/getauxval.c b/misc/getauxval.c
index 714ce5bd62..a4625b8596 100644
--- a/misc/getauxval.c
+++ b/misc/getauxval.c
@@ -20,6 +20,39 @@
#include <ldsodefs.h>
#include <stdbool.h>
+void *
+__getauxptr (unsigned long int type)
+{
+ /* error if asking for a non-pointer from getauxptr(). This list is not a
+ perfect enforcement as it currently supports both transitional and draft
+ ABIs, which have different capability entries. */
+ switch (type) {
+ case AT_ENTRY:
+ case AT_PHDR:
+ case AT_BASE:
+ case AT_SYSINFO_EHDR:
+ case AT_EXECFN:
+ case AT_RANDOM:
+ case AT_PLATFORM:
+ case AT_CHERI_EXEC_RW_CAP:
+ case AT_CHERI_EXEC_RX_CAP:
+ case AT_CHERI_INTERP_RW_CAP:
+ case AT_CHERI_INTERP_RX_CAP:
+ case AT_CHERI_SEAL_CAP:
+ {
+ ElfW(auxv_t) *p;
+ for (p = GLRO(dl_auxv); p->a_type != AT_NULL; p++)
+ if (p->a_type == type)
+ return (void *) p->a_un.a_val;
+ }
+ }
+
+ __set_errno (ENOENT);
+ return 0;
+}
+weak_alias (__getauxptr, getauxptr)
+libc_hidden_def (__getauxptr)
+
bool
__getauxval2 (unsigned long int type, unsigned long int *result)
{
diff --git a/misc/sys/auxv.h b/misc/sys/auxv.h
index b5ab30ab77..8446aeddd0 100644
--- a/misc/sys/auxv.h
+++ b/misc/sys/auxv.h
@@ -31,6 +31,10 @@ __BEGIN_DECLS
extern unsigned long int getauxval (unsigned long int __type)
__THROW;
+/* Same as getauxval, but for Arm Morello capabilities. */
+extern void * getauxptr (unsigned long int __type)
+ __THROW;
+
__END_DECLS
#endif /* sys/auxv.h */