diff options
| -rw-r--r-- | elf/dl-load.c | 94 | ||||
| -rw-r--r-- | elf/rtld.c | 14 | ||||
| -rw-r--r-- | sysdeps/generic/dl-prop.h | 23 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 4 | ||||
| -rw-r--r-- | sysdeps/x86/dl-prop.h | 47 |
5 files changed, 118 insertions, 64 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c index 06f2ba7264..e39980fb19 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -853,6 +853,77 @@ lose (int code, int fd, const char *name, char *realname, struct link_map *l, } +/* Process PT_GNU_PROPERTY program header PH in module L after + PT_LOAD segments are mapped. Only one NT_GNU_PROPERTY_TYPE_0 + note is handled which contains processor specific properties. */ + +void +_dl_process_pt_gnu_property (struct link_map *l, const ElfW(Phdr) *ph) +{ + const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr); + const ElfW(Addr) size = ph->p_memsz; + const ElfW(Addr) align = ph->p_align; + + /* The NT_GNU_PROPERTY_TYPE_0 note must be aligned to 4 bytes in + 32-bit objects and to 8 bytes in 64-bit objects. Skip notes + with incorrect alignment. */ + if (align != (__ELF_NATIVE_CLASS / 8)) + return; + + const ElfW(Addr) start = (ElfW(Addr)) note; + unsigned int last_type = 0; + + while ((ElfW(Addr)) (note + 1) - start < size) + { + /* Find the NT_GNU_PROPERTY_TYPE_0 note. */ + if (note->n_namesz == 4 + && note->n_type == NT_GNU_PROPERTY_TYPE_0 + && memcmp (note + 1, "GNU", 4) == 0) + { + /* Check for invalid property. */ + if (note->n_descsz < 8 + || (note->n_descsz % sizeof (ElfW(Addr))) != 0) + return; + + /* Start and end of property array. */ + unsigned char *ptr = (unsigned char *) (note + 1) + 4; + unsigned char *ptr_end = ptr + note->n_descsz; + + do + { + unsigned int type = *(unsigned int *) ptr; + unsigned int datasz = *(unsigned int *) (ptr + 4); + + /* Property type must be in ascending order. */ + if (type < last_type) + return; + + ptr += 8; + if ((ptr + datasz) > ptr_end) + return; + + last_type = type; + + /* Target specific property processing. */ + if (_dl_process_gnu_property (l, type, datasz, ptr) == 0) + return; + + /* Check the next property item. */ + ptr += ALIGN_UP (datasz, sizeof (ElfW(Addr))); + } + while ((ptr_end - ptr) >= 8); + + /* Only handle one NT_GNU_PROPERTY_TYPE_0. */ + return; + } + + note = ((const void *) note + + ELF_NOTE_NEXT_OFFSET (note->n_namesz, note->n_descsz, + align)); + } +} + + /* Map in the shared object NAME, actually located in REALNAME, and already opened on FD. */ @@ -1145,14 +1216,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, l->l_relro_addr = ph->p_vaddr; l->l_relro_size = ph->p_memsz; break; - - case PT_NOTE: - if (_dl_process_pt_note (l, ph, fd, fbp)) - { - errstring = N_("cannot process note segment"); - goto call_lose; - } - break; } if (__glibc_unlikely (nloadcmds == 0)) @@ -1188,6 +1251,21 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, maplength, has_holes, loader); if (__glibc_unlikely (errstring != NULL)) goto call_lose; + + /* Process program headers again after load segments are mapped in + case processing requires accessing those segments. Scan program + headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY + exits. */ + for (ph = &phdr[l->l_phnum]; ph != phdr; --ph) + switch (ph[-1].p_type) + { + case PT_NOTE: + _dl_process_pt_note (l, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (l, &ph[-1]); + break; + } } if (l->l_ld == 0) diff --git a/elf/rtld.c b/elf/rtld.c index 882b070cc0..f4c2602d65 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1507,11 +1507,17 @@ of this helper program; chances are you did not intend to run this program.\n\ main_map->l_relro_addr = ph->p_vaddr; main_map->l_relro_size = ph->p_memsz; break; - + } + /* Process program headers again, but scan them backwards so + that PT_NOTE can be skipped if PT_GNU_PROPERTY exits. */ + for (ph = &phdr[phnum]; ph != phdr; --ph) + switch (ph[-1].p_type) + { case PT_NOTE: - if (_rtld_process_pt_note (main_map, ph)) - _dl_error_printf ("\ -ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); + _dl_process_pt_note (main_map, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (main_map, &ph[-1]); break; } diff --git a/sysdeps/generic/dl-prop.h b/sysdeps/generic/dl-prop.h index 6b0f2aa95a..f1cf576fe3 100644 --- a/sysdeps/generic/dl-prop.h +++ b/sysdeps/generic/dl-prop.h @@ -20,11 +20,11 @@ #define _DL_PROP_H /* The following functions are used by the dynamic loader and the - dlopen machinery to process PT_NOTE entries in the binary or - shared object. The notes can be used to change the behaviour of - the loader, and as such offer a flexible mechanism for hooking in - various checks related to ABI tags or implementing "flag day" ABI - transitions. */ + dlopen machinery to process PT_NOTE and PT_GNU_PROPERTY entries in + the binary or shared object. The notes can be used to change the + behaviour of the loader, and as such offer a flexible mechanism + for hooking in various checks related to ABI tags or implementing + "flag day" ABI transitions. */ static inline void __attribute__ ((always_inline)) _rtld_main_check (struct link_map *m, const char *program) @@ -36,17 +36,16 @@ _dl_open_check (struct link_map *m) { } -#ifdef FILEBUF_SIZE -static inline int __attribute__ ((always_inline)) -_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph, - int fd, struct filebuf *fbp) +static inline void __attribute__ ((always_inline)) +_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph) { - return 0; } -#endif +/* Called for each property in the NT_GNU_PROPERTY_TYPE_0 note of L, + processing of the properties continues until this returns 0. */ static inline int __attribute__ ((always_inline)) -_rtld_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph) +_dl_process_gnu_property (struct link_map *l, uint32_t type, uint32_t datasz, + void *data) { return 0; } diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index d08b97a5ef..c525ffa12c 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -910,6 +910,10 @@ extern void _dl_setup_hash (struct link_map *map) attribute_hidden; extern void _dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting); +/* Process PT_GNU_PROPERTY program header PH in module L after + PT_LOAD segments are mapped. */ +void _dl_process_pt_gnu_property (struct link_map *l, const ElfW(Phdr) *ph); + /* Search loaded objects' symbol tables for a definition of the symbol referred to by UNDEF. *SYM is the symbol table entry containing the diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h index 516f88ea80..89911e19e2 100644 --- a/sysdeps/x86/dl-prop.h +++ b/sysdeps/x86/dl-prop.h @@ -19,8 +19,6 @@ #ifndef _DL_PROP_H #define _DL_PROP_H -#include <not-cancel.h> - extern void _dl_cet_check (struct link_map *, const char *) attribute_hidden; extern void _dl_cet_open_check (struct link_map *) @@ -146,48 +144,17 @@ _dl_process_cet_property_note (struct link_map *l, #endif } -#ifdef FILEBUF_SIZE -static inline int __attribute__ ((unused)) -_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph, - int fd, struct filebuf *fbp) +static inline void __attribute__ ((unused)) +_dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph) { -# if CET_ENABLED - const ElfW(Nhdr) *note; - ElfW(Nhdr) *note_malloced = NULL; - ElfW(Addr) size = ph->p_filesz; - - if (ph->p_offset + size <= (size_t) fbp->len) - note = (const void *) (fbp->buf + ph->p_offset); - else - { - if (size < __MAX_ALLOCA_CUTOFF) - note = alloca (size); - else - { - note_malloced = malloc (size); - note = note_malloced; - } - if (__pread64_nocancel (fd, (void *) note, size, ph->p_offset) != size) - { - if (note_malloced) - free (note_malloced); - return -1; - } - } - - _dl_process_cet_property_note (l, note, size, ph->p_align); - if (note_malloced) - free (note_malloced); -# endif - return 0; + const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr); + _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align); } -#endif -static inline int __attribute__ ((unused)) -_rtld_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph) +static inline int __attribute__ ((always_inline)) +_dl_process_gnu_property (struct link_map *l, uint32_t type, uint32_t datasz, + void *data) { - const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr); - _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align); return 0; } |