From 6099908fb84debee4c3bcb05d88769410c2aecd1 Mon Sep 17 00:00:00 2001 From: Javier Pello Date: Tue, 27 Sep 2022 20:05:59 +0200 Subject: elf: Remove legacy hwcaps support from the dynamic loader Remove support for the legacy hwcaps subdirectories from the dynamic loader. Signed-off-by: Javier Pello Reviewed-by: Florian Weimer --- elf/Makefile | 6 -- elf/dl-hwcaps.c | 184 +++----------------------------------------------------- elf/dl-usage.c | 32 ---------- 3 files changed, 10 insertions(+), 212 deletions(-) (limited to 'elf') diff --git a/elf/Makefile b/elf/Makefile index 008770b..276343a 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -2689,12 +2689,6 @@ $(objpfx)tst-rtld-help.out: $(objpfx)ld.so $(test-wrapper) $(rtld-prefix) --help > $@; \ status=$$?; \ echo "info: ld.so exit status: $$status" >> $@; \ - if ! grep -q 'Legacy HWCAP subdirectories under library search path directories' $@; then \ - echo "error: missing subdirectory pattern" >> $@; \ - if test $$status -eq 0; then \ - status=1; \ - fi; \ - fi; \ (exit $$status); \ $(evaluate-test) diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c index 92eb537..ae2423e 100644 --- a/elf/dl-hwcaps.c +++ b/elf/dl-hwcaps.c @@ -170,17 +170,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, const char *glibc_hwcaps_mask, size_t *sz, size_t *max_capstrlen) { - uint64_t hwcap_mask = GET_HWCAP_MASK(); - /* Determine how many important bits are set. */ - uint64_t masked = GLRO(dl_hwcap) & hwcap_mask; - size_t cnt = GLRO (dl_platform) != NULL; - size_t n, m; - struct r_strlenpair *result; - struct r_strlenpair *rp; - char *cp; - - /* glibc-hwcaps subdirectories. These are exempted from the power - set construction below. */ + /* glibc-hwcaps subdirectories. */ uint32_t hwcaps_subdirs_active = _dl_hwcaps_subdirs_active (); struct hwcaps_counts hwcaps_counts = { 0, }; update_hwcaps_counts (&hwcaps_counts, glibc_hwcaps_prepend, -1, NULL); @@ -193,72 +183,14 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, /* Each hwcaps subdirectory has a GLIBC_HWCAPS_PREFIX string prefix and a "/" suffix once stored in the result. */ hwcaps_counts.maximum_length += strlen (GLIBC_HWCAPS_PREFIX) + 1; - size_t hwcaps_sz = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) + size_t total = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1) + hwcaps_counts.total_length); - /* Count the number of bits set in the masked value. */ - for (n = 0; (~((1ULL << n) - 1) & masked) != 0; ++n) - if ((masked & (1ULL << n)) != 0) - ++cnt; - - /* For TLS enabled builds always add 'tls'. */ - ++cnt; - - /* Create temporary data structure to generate result table. */ - struct r_strlenpair temp[cnt]; - m = 0; - for (n = 0; masked != 0; ++n) - if ((masked & (1ULL << n)) != 0) - { - temp[m].str = _dl_hwcap_string (n); - temp[m].len = strlen (temp[m].str); - masked ^= 1ULL << n; - ++m; - } - if (GLRO (dl_platform) != NULL) - { - temp[m].str = GLRO (dl_platform); - temp[m].len = GLRO (dl_platformlen); - ++m; - } - - temp[m].str = "tls"; - temp[m].len = 3; - ++m; - - assert (m == cnt); - - /* Determine the total size of all strings together. */ - size_t total; - if (cnt == 1) - total = temp[0].len + 1; - else - { - total = temp[0].len + temp[cnt - 1].len + 2; - if (cnt > 2) - { - total <<= 1; - for (n = 1; n + 1 < cnt; ++n) - total += temp[n].len + 1; - if (cnt > 3 - && (cnt >= sizeof (size_t) * 8 - || total + (sizeof (*result) << 3) - >= (1UL << (sizeof (size_t) * 8 - cnt + 3)))) - _dl_signal_error (ENOMEM, NULL, NULL, - N_("cannot create capability list")); - - total <<= cnt - 3; - } - } + *sz = hwcaps_counts.count + 1; - *sz = hwcaps_counts.count + (1 << cnt); - - /* This is the overall result, including both glibc-hwcaps - subdirectories and the legacy hwcaps subdirectories using the - power set construction. */ - total += hwcaps_sz; + /* This is the overall result. */ struct r_strlenpair *overall_result - = malloc (*sz * sizeof (*result) + total); + = malloc (*sz * sizeof (*overall_result) + total); if (overall_result == NULL) _dl_signal_error (ENOMEM, NULL, NULL, N_("cannot create capability list")); @@ -271,110 +203,14 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend, copy_hwcaps (&target, glibc_hwcaps_prepend, -1, NULL); copy_hwcaps (&target, _dl_hwcaps_subdirs, hwcaps_subdirs_active, glibc_hwcaps_mask); - /* Set up the write target for the power set construction. */ - result = target.next_pair; - cp = target.next_string; - } - - /* Power set construction begins here. We use a very compressed way - to store the various combinations of capability names. */ - - if (cnt == 1) - { - result[0].str = cp; - result[0].len = temp[0].len + 1; - result[1].str = cp; - result[1].len = 0; - cp = __mempcpy (cp, temp[0].str, temp[0].len); - *cp = '/'; - if (result[0].len > hwcaps_counts.maximum_length) - *max_capstrlen = result[0].len; - else - *max_capstrlen = hwcaps_counts.maximum_length; - - return overall_result; - } - - /* Fill in the information. This follows the following scheme - (indices from TEMP for four strings): - entry #0: 0, 1, 2, 3 binary: 1111 - #1: 0, 1, 3 1101 - #2: 0, 2, 3 1011 - #3: 0, 3 1001 - This allows the representation of all possible combinations of - capability names in the string. First generate the strings. */ - result[1].str = result[0].str = cp; -#define add(idx) \ - cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1); - if (cnt == 2) - { - add (1); - add (0); - } - else - { - n = 1 << (cnt - 1); - do - { - n -= 2; - - /* We always add the last string. */ - add (cnt - 1); - - /* Add the strings which have the bit set in N. */ - for (m = cnt - 2; m > 0; --m) - if ((n & (1 << m)) != 0) - add (m); - - /* Always add the first string. */ - add (0); - } - while (n != 0); - } -#undef add - - /* Now we are ready to install the string pointers and length. */ - for (n = 0; n < (1UL << cnt); ++n) - result[n].len = 0; - n = cnt; - do - { - size_t mask = 1 << --n; - - rp = result; - for (m = 1 << cnt; m > 0; ++rp) - if ((--m & mask) != 0) - rp->len += temp[n].len + 1; - } - while (n != 0); - - /* The first half of the strings all include the first string. */ - n = (1 << cnt) - 2; - rp = &result[2]; - while (n != (1UL << (cnt - 1))) - { - if ((--n & 1) != 0) - rp[0].str = rp[-2].str + rp[-2].len; - else - rp[0].str = rp[-1].str; - ++rp; - } - - /* The second half starts right after the first part of the string of - the corresponding entry in the first half. */ - do - { - rp[0].str = rp[-(1 << (cnt - 1))].str + temp[cnt - 1].len + 1; - ++rp; - } - while (--n != 0); + /* Append an empty entry for the base directory itself. */ + target.next_pair->str = target.next_string; + target.next_pair->len = 0; + } /* The maximum string length. */ - if (result[0].len > hwcaps_counts.maximum_length) - *max_capstrlen = result[0].len; - else - *max_capstrlen = hwcaps_counts.maximum_length; + *max_capstrlen = hwcaps_counts.maximum_length; return overall_result; } diff --git a/elf/dl-usage.c b/elf/dl-usage.c index 98d8c98..efd6c77 100644 --- a/elf/dl-usage.c +++ b/elf/dl-usage.c @@ -193,37 +193,6 @@ print_hwcaps_subdirectories (const struct dl_main_state *state) No subdirectories of glibc-hwcaps directories are searched.\n"); } -/* Write a list of hwcap subdirectories to standard output. See - _dl_important_hwcaps in dl-hwcaps.c. */ -static void -print_legacy_hwcap_directories (void) -{ - _dl_printf ("\n\ -Legacy HWCAP subdirectories under library search path directories:\n"); - - const char *platform = GLRO (dl_platform); - if (platform != NULL) - _dl_printf (" %s (AT_PLATFORM; supported, searched)\n", platform); - - _dl_printf (" tls (supported, searched)\n"); - - uint64_t hwcap_mask = GET_HWCAP_MASK(); - uint64_t searched = GLRO (dl_hwcap) & hwcap_mask; - for (int n = 63; n >= 0; --n) - { - uint64_t bit = 1ULL << n; - if (HWCAP_IMPORTANT & bit) - { - _dl_printf (" %s", _dl_hwcap_string (n)); - bool first = true; - print_hwcap_1 (&first, GLRO (dl_hwcap) & bit, "supported"); - print_hwcap_1 (&first, !(hwcap_mask & bit), "masked"); - print_hwcap_1 (&first, searched & bit, "searched"); - print_hwcap_1_finish (&first); - } - } -} - void _dl_help (const char *argv0, struct dl_main_state *state) { @@ -270,6 +239,5 @@ This program interpreter self-identifies as: " RTLD "\n\ argv0); print_search_path_for_help (state); print_hwcaps_subdirectories (state); - print_legacy_hwcap_directories (); _exit (EXIT_SUCCESS); } -- cgit v1.1