From: Javier Pello <devel@otheo.eu>
To: libc-alpha@sourceware.org
Subject: [PATCH v3 2/8] elf: Remove legacy hwcaps support from the dynamic loader
Date: Tue, 27 Sep 2022 20:05:59 +0200 [thread overview]
Message-ID: <20220927200559.9c8be95bc240f7ed0f045a9d@otheo.eu> (raw)
In-Reply-To: <20220927200352.0424a12908a437fef9d3a7bc@otheo.eu>
Remove support for the legacy hwcaps subdirectories from the dynamic
loader.
Signed-off-by: Javier Pello <devel@otheo.eu>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
---
elf/Makefile | 6 --
elf/dl-hwcaps.c | 184 +++---------------------------------------------
elf/dl-usage.c | 32 ---------
3 files changed, 10 insertions(+), 212 deletions(-)
diff --git a/elf/Makefile b/elf/Makefile
index 008770bf..276343a4 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 92eb5379..ae2423eb 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 98d8c989..efd6c77c 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);
}
--
2.37.3
next prev parent reply other threads:[~2022-09-27 18:05 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-05 18:06 [PATCH 0/4] elf: Fix hwcaps string size overestimation Javier Pello
2022-09-05 18:09 ` [PATCH 1/4] " Javier Pello
2022-09-08 10:15 ` Florian Weimer
2022-09-05 18:10 ` [PATCH 2/4] elf: Simplify hwcaps masked value bit counting Javier Pello
2022-09-05 18:12 ` [PATCH 3/4] elf: Remove unneeded conditional in _dl_important_hwcaps Javier Pello
2022-09-05 18:13 ` [PATCH 4/4] elf: Simplify hwcaps power set string construction Javier Pello
2022-09-06 7:35 ` [PATCH 0/4] elf: Fix hwcaps string size overestimation Florian Weimer
2022-09-06 18:12 ` Javier Pello
2022-09-08 11:23 ` Florian Weimer
2022-09-14 18:07 ` [PATCH 0/6] Remove legacy hwcaps support Javier Pello
2022-09-14 18:08 ` [PATCH 1/6] elf: Remove legacy hwcaps support from the dynamic loader Javier Pello
2022-09-14 18:10 ` [PATCH 2/6] elf: Remove legacy hwcaps support from ldconfig Javier Pello
2022-09-14 18:10 ` [PATCH 3/6] elf: Remove hwcap parameter from add_to_cache signature Javier Pello
2022-09-14 18:12 ` [PATCH 4/6] elf: Remove hwcap and bits_hwcap fields from struct cache_entry Javier Pello
2022-09-14 18:13 ` [PATCH 5/6] elf: Remove _dl_string_hwcap Javier Pello
2022-09-14 18:15 ` [PATCH 6/6] elf: Simplify output of hwcap subdirectories in ld.so help Javier Pello
2022-09-15 8:42 ` Carlos O'Donell
2022-09-15 19:12 ` Javier Pello
2022-09-14 21:23 ` [PATCH 0/6] Remove legacy hwcaps support Joseph Myers
2022-09-17 14:17 ` [PATCH v2 " Javier Pello
2022-09-17 14:18 ` [PATCH v2 1/6] elf: Remove legacy hwcaps support from the dynamic loader Javier Pello
2022-09-22 11:46 ` Florian Weimer
2022-09-17 14:19 ` [PATCH v2 2/6] elf: Remove legacy hwcaps support from ldconfig Javier Pello
2022-09-22 12:14 ` Florian Weimer
2022-09-17 14:20 ` [PATCH v2 3/6] elf: Remove hwcap parameter from add_to_cache signature Javier Pello
2022-09-22 16:02 ` Florian Weimer
2022-09-17 14:22 ` [PATCH v2 4/6] elf: Remove hwcap and bits_hwcap fields from struct cache_entry Javier Pello
2022-09-22 16:03 ` Florian Weimer
2022-09-17 14:23 ` [PATCH v2 5/6] elf: Remove _dl_string_hwcap Javier Pello
2022-09-17 14:24 ` [PATCH v2 6/6] elf: Simplify output of hwcap subdirectories in ld.so help Javier Pello
2022-09-21 16:26 ` [PATCH v2 0/6] Remove legacy hwcaps support Joseph Myers
2022-09-27 18:03 ` [PATCH v3 0/8] " Javier Pello
2022-09-27 18:05 ` [PATCH v3 1/8] x86_64: Remove platform directory library loading test Javier Pello
2022-10-03 14:56 ` Adhemerval Zanella Netto
2022-10-04 17:53 ` Javier Pello
2022-10-04 17:59 ` Adhemerval Zanella Netto
2022-09-27 18:05 ` Javier Pello [this message]
2022-09-27 18:06 ` [PATCH v3 3/8] elf: Remove legacy hwcaps support from ldconfig Javier Pello
2022-10-03 15:31 ` Adhemerval Zanella Netto
2022-09-27 18:07 ` [PATCH v3 4/8] elf: Remove hwcap parameter from add_to_cache signature Javier Pello
2022-09-27 18:08 ` [PATCH v3 5/8] elf: Remove hwcap and bits_hwcap fields from struct cache_entry Javier Pello
2022-09-27 18:08 ` [PATCH v3 6/8] Add NEWS entry for legacy hwcaps removal Javier Pello
2022-10-03 15:44 ` Adhemerval Zanella Netto
2022-10-03 19:29 ` Andreas Schwab
2022-10-03 19:49 ` Adhemerval Zanella Netto
2022-10-03 19:59 ` Florian Weimer
2022-10-04 18:00 ` Adhemerval Zanella Netto
2022-10-05 18:12 ` Javier Pello
2022-10-06 11:03 ` Adhemerval Zanella Netto
2022-09-27 18:09 ` [PATCH v3 7/8] elf: Remove _dl_string_hwcap Javier Pello
2022-10-03 16:52 ` Adhemerval Zanella Netto
2022-09-27 18:10 ` [PATCH v3 8/8] elf: Simplify output of hwcap subdirectories in ld.so help Javier Pello
2022-10-03 17:02 ` Adhemerval Zanella Netto
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