diff options
Diffstat (limited to 'elf/dl-hwcaps.c')
| -rw-r--r-- | elf/dl-hwcaps.c | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c index 71aea86700..6df9efb255 100644 --- a/elf/dl-hwcaps.c +++ b/elf/dl-hwcaps.c @@ -26,12 +26,6 @@ #include <dl-procinfo.h> #include <dl-hwcaps.h> -#ifdef _DL_FIRST_PLATFORM -# define _DL_FIRST_EXTRA (_DL_FIRST_PLATFORM + _DL_PLATFORMS_COUNT) -#else -# define _DL_FIRST_EXTRA _DL_HWCAP_COUNT -#endif - /* Return an array of useful/necessary hardware capability names. */ const struct r_strlenpair * _dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz, @@ -52,116 +46,12 @@ _dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz, if ((masked & (1ULL << n)) != 0) ++cnt; -#ifdef NEED_DL_SYSINFO_DSO - /* The system-supplied DSO can contain a note of type 2, vendor "GNU". - This gives us a list of names to treat as fake hwcap bits. */ - - const char *dsocaps = NULL; - size_t dsocapslen = 0; - if (GLRO(dl_sysinfo_map) != NULL) - { - const ElfW(Phdr) *const phdr = GLRO(dl_sysinfo_map)->l_phdr; - const ElfW(Word) phnum = GLRO(dl_sysinfo_map)->l_phnum; - for (uint_fast16_t i = 0; i < phnum; ++i) - if (phdr[i].p_type == PT_NOTE) - { - const ElfW(Addr) start = (phdr[i].p_vaddr - + GLRO(dl_sysinfo_map)->l_addr); - /* NB: Some PT_NOTE segment may have alignment value of 0 - or 1. gABI specifies that PT_NOTE segments should be - aligned to 4 bytes in 32-bit objects and to 8 bytes in - 64-bit objects. As a Linux extension, we also support - 4 byte alignment in 64-bit objects. If p_align is less - than 4, we treate alignment as 4 bytes since some note - segments have 0 or 1 byte alignment. */ - ElfW(Addr) align = phdr[i].p_align; - if (align < 4) - align = 4; - else if (align != 4 && align != 8) - continue; - /* The standard ELF note layout is exactly as the anonymous struct. - The next element is a variable length vendor name of length - VENDORLEN (with a real length rounded to ElfW(Word)), followed - by the data of length DATALEN (with a real length rounded to - ElfW(Word)). */ - const struct - { - ElfW(Word) vendorlen; - ElfW(Word) datalen; - ElfW(Word) type; - } *note = (const void *) start; - while ((ElfW(Addr)) (note + 1) - start < phdr[i].p_memsz) - { - /* The layout of the type 2, vendor "GNU" note is as follows: - .long <Number of capabilities enabled by this note> - .long <Capabilities mask> (as mask >> _DL_FIRST_EXTRA). - .byte <The bit number for the next capability> - .asciz <The name of the capability>. */ - if (note->type == NT_GNU_HWCAP - && note->vendorlen == sizeof "GNU" - && !memcmp ((note + 1), "GNU", sizeof "GNU") - && note->datalen > 2 * sizeof (ElfW(Word)) + 2) - { - const ElfW(Word) *p - = ((const void *) note - + ELF_NOTE_DESC_OFFSET (sizeof "GNU", align)); - cnt += *p++; - ++p; /* Skip mask word. */ - dsocaps = (const char *) p; /* Pseudo-string "<b>name" */ - dsocapslen = note->datalen - sizeof *p * 2; - break; - } - note = ((const void *) note - + ELF_NOTE_NEXT_OFFSET (note->vendorlen, - note->datalen, align)); - } - if (dsocaps != NULL) - break; - } - } -#endif - /* For TLS enabled builds always add 'tls'. */ ++cnt; /* Create temporary data structure to generate result table. */ struct r_strlenpair temp[cnt]; m = 0; -#ifdef NEED_DL_SYSINFO_DSO - if (dsocaps != NULL) - { - /* dsocaps points to the .asciz string, and -1 points to the mask - .long just before the string. */ - const ElfW(Word) mask = ((const ElfW(Word) *) dsocaps)[-1]; - GLRO(dl_hwcap) |= (uint64_t) mask << _DL_FIRST_EXTRA; - /* Note that we add the dsocaps to the set already chosen by the - LD_HWCAP_MASK environment variable (or default HWCAP_IMPORTANT). - So there is no way to request ignoring an OS-supplied dsocap - string and bit like you can ignore an OS-supplied HWCAP bit. */ - hwcap_mask |= (uint64_t) mask << _DL_FIRST_EXTRA; -#if HAVE_TUNABLES - TUNABLE_SET (glibc, cpu, hwcap_mask, uint64_t, hwcap_mask); -#else - GLRO(dl_hwcap_mask) = hwcap_mask; -#endif - size_t len; - for (const char *p = dsocaps; p < dsocaps + dsocapslen; p += len + 1) - { - uint_fast8_t bit = *p++; - len = strlen (p); - - /* Skip entries that are not enabled in the mask word. */ - if (__glibc_likely (mask & ((ElfW(Word)) 1 << bit))) - { - temp[m].str = p; - temp[m].len = len; - ++m; - } - else - --cnt; - } - } -#endif for (n = 0; masked != 0; ++n) if ((masked & (1ULL << n)) != 0) { |