1 /* Support for GNU properties. x86 version.
2 Copyright (C) 2018-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
24 extern void _dl_cet_check (struct link_map
*, const char *)
26 extern void _dl_cet_open_check (struct link_map
*)
30 dl_isa_level_check (struct link_map
*m
, const char *program
)
32 const struct cpu_features
*cpu_features
= __get_cpu_features ();
36 i
= m
->l_searchlist
.r_nlist
;
39 /* Check each shared object to see if ISA level is compatible. */
42 /* Skip ISA level check if functions have been executed. */
47 /* Skip ISA level check for ld.so since ld.so won't run if its ISA
48 level is higher than CPU. */
49 if (l
== &GL(dl_rtld_map
) || l
->l_real
== &GL(dl_rtld_map
))
53 if ((l
->l_x86_isa_1_needed
& cpu_features
->isa_1
)
54 != l
->l_x86_isa_1_needed
)
57 _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
58 *l
->l_name
!= '\0' ? l
->l_name
: program
);
60 _dl_signal_error (0, l
->l_name
, "dlopen",
61 N_("CPU ISA level is lower than required"));
66 static inline void __attribute__ ((always_inline
))
67 _rtld_main_check (struct link_map
*m
, const char *program
)
69 dl_isa_level_check (m
, program
);
71 _dl_cet_check (m
, program
);
75 static inline void __attribute__ ((always_inline
))
76 _dl_open_check (struct link_map
*m
)
78 dl_isa_level_check (m
, NULL
);
80 _dl_cet_open_check (m
);
84 static inline void __attribute__ ((unused
))
85 _dl_process_property_note (struct link_map
*l
, const ElfW(Nhdr
) *note
,
86 const ElfW(Addr
) size
, const ElfW(Addr
) align
)
88 /* Skip if we have seen a NT_GNU_PROPERTY_TYPE_0 note before. */
89 if (l
->l_property
!= lc_property_unknown
)
92 /* The NT_GNU_PROPERTY_TYPE_0 note must be aligned to 4 bytes in
93 32-bit objects and to 8 bytes in 64-bit objects. Skip notes
94 with incorrect alignment. */
95 if (align
!= (__ELF_NATIVE_CLASS
/ 8))
98 const ElfW(Addr
) start
= (ElfW(Addr
)) note
;
100 unsigned int needed_1
= 0;
101 unsigned int feature_1_and
= 0;
102 unsigned int isa_1_needed
= 0;
103 unsigned int last_type
= 0;
105 while ((ElfW(Addr
)) (note
+ 1) - start
< size
)
107 /* Find the NT_GNU_PROPERTY_TYPE_0 note. */
108 if (note
->n_namesz
== 4
109 && note
->n_type
== NT_GNU_PROPERTY_TYPE_0
110 && memcmp (note
+ 1, "GNU", 4) == 0)
112 /* Stop if we see more than one GNU property note which may
113 be generated by the older linker. */
114 if (l
->l_property
!= lc_property_unknown
)
117 /* Check CET status and ISA levels now. */
118 l
->l_property
= lc_property_none
;
120 /* Check for invalid property. */
121 if (note
->n_descsz
< 8
122 || (note
->n_descsz
% sizeof (ElfW(Addr
))) != 0)
125 /* Start and end of property array. */
126 unsigned char *ptr
= (unsigned char *) (note
+ 1) + 4;
127 unsigned char *ptr_end
= ptr
+ note
->n_descsz
;
131 unsigned int type
= *(unsigned int *) ptr
;
132 unsigned int datasz
= *(unsigned int *) (ptr
+ 4);
134 /* Property type must be in ascending order. */
135 if (type
< last_type
)
139 if ((ptr
+ datasz
) > ptr_end
)
144 if (type
== GNU_PROPERTY_X86_FEATURE_1_AND
145 || type
== GNU_PROPERTY_X86_ISA_1_NEEDED
146 || type
== GNU_PROPERTY_1_NEEDED
)
148 /* The sizes of types which we are searching for are
149 4 bytes. There is no point to continue if this
150 note is ill-formed. */
154 /* NB: Stop the scan only after seeing all types which
155 we are searching for. */
156 _Static_assert (((GNU_PROPERTY_X86_ISA_1_NEEDED
157 > GNU_PROPERTY_X86_FEATURE_1_AND
)
158 && (GNU_PROPERTY_X86_FEATURE_1_AND
159 > GNU_PROPERTY_1_NEEDED
)),
160 "GNU_PROPERTY_X86_ISA_1_NEEDED > "
161 "GNU_PROPERTY_X86_FEATURE_1_AND && "
162 "GNU_PROPERTY_X86_FEATURE_1_AND > "
163 "GNU_PROPERTY_1_NEEDED");
164 if (type
== GNU_PROPERTY_X86_FEATURE_1_AND
)
165 feature_1_and
= *(unsigned int *) ptr
;
166 else if (type
== GNU_PROPERTY_1_NEEDED
)
167 needed_1
= *(unsigned int *) ptr
;
170 isa_1_needed
= *(unsigned int *) ptr
;
172 /* Keep searching for the next GNU property note
173 generated by the older linker. */
177 else if (type
> GNU_PROPERTY_X86_ISA_1_NEEDED
)
179 /* Stop the scan since property type is in ascending
184 /* Check the next property item. */
185 ptr
+= ALIGN_UP (datasz
, sizeof (ElfW(Addr
)));
187 while ((ptr_end
- ptr
) >= 8);
190 /* NB: Note sections like .note.ABI-tag and .note.gnu.build-id are
191 aligned to 4 bytes in 64-bit ELF objects. */
192 note
= ((const void *) note
193 + ELF_NOTE_NEXT_OFFSET (note
->n_namesz
, note
->n_descsz
,
197 /* We get here only if there is one or no GNU property note. */
198 if (needed_1
!= 0 || isa_1_needed
!= 0 || feature_1_and
!= 0)
200 l
->l_property
= lc_property_valid
;
201 l
->l_1_needed
= needed_1
;
202 l
->l_x86_isa_1_needed
= isa_1_needed
;
203 l
->l_x86_feature_1_and
= feature_1_and
;
206 l
->l_property
= lc_property_none
;
209 static inline void __attribute__ ((unused
))
210 _dl_process_pt_note (struct link_map
*l
, int fd
, const ElfW(Phdr
) *ph
)
212 const ElfW(Nhdr
) *note
= (const void *) (ph
->p_vaddr
+ l
->l_addr
);
213 _dl_process_property_note (l
, note
, ph
->p_memsz
, ph
->p_align
);
216 static inline int __attribute__ ((always_inline
))
217 _dl_process_gnu_property (struct link_map
*l
, int fd
, uint32_t type
,
218 uint32_t datasz
, void *data
)
223 #endif /* _DL_PROP_H */