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| author | Carlos Eduardo Seo <carlos.seo@arm.com> | 2022-05-18 00:52:09 +0000 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-10-27 14:46:55 +0100 |
| commit | 3386ca6696dbf1578fe605f9b380931052bd7329 (patch) | |
| tree | b62f21af673e8f6bd8bf97cc9cd390a5f0ec0caf | |
| parent | fac448ae9edb57ad6a8415ecfa6ef5dad61a9d0c (diff) | |
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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.h | 4 | ||||
| -rw-r--r-- | misc/Versions | 3 | ||||
| -rw-r--r-- | misc/getauxval.c | 33 | ||||
| -rw-r--r-- | misc/sys/auxv.h | 4 |
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 */ |