diff options
| -rw-r--r-- | elf/Makefile | 71 | ||||
| -rw-r--r-- | elf/dl-hwcaps-subdirs.c | 29 | ||||
| -rw-r--r-- | elf/dl-hwcaps.c | 138 | ||||
| -rw-r--r-- | elf/dl-hwcaps.h | 105 | ||||
| -rw-r--r-- | elf/dl-hwcaps_split.c | 77 | ||||
| -rw-r--r-- | elf/dl-load.c | 7 | ||||
| -rw-r--r-- | elf/dl-main.h | 11 | ||||
| -rw-r--r-- | elf/dl-support.c | 5 | ||||
| -rw-r--r-- | elf/dl-usage.c | 68 | ||||
| -rw-r--r-- | elf/markermodMARKER-VALUE.c | 29 | ||||
| -rw-r--r-- | elf/rtld.c | 18 | ||||
| -rw-r--r-- | elf/tst-dl-hwcaps_split.c | 148 | ||||
| -rw-r--r-- | elf/tst-glibc-hwcaps-mask.c | 31 | ||||
| -rw-r--r-- | elf/tst-glibc-hwcaps-prepend.c | 32 | ||||
| -rw-r--r-- | elf/tst-glibc-hwcaps.c | 28 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 20 |
16 files changed, 784 insertions, 33 deletions
diff --git a/elf/Makefile b/elf/Makefile index a494b14..db10541 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -61,7 +61,8 @@ elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \ # ld.so uses those routines, plus some special stuff for being the program # interpreter and operating independent of libc. rtld-routines = rtld $(all-dl-routines) dl-sysdep dl-environ dl-minimal \ - dl-error-minimal dl-conflict dl-hwcaps dl-usage + dl-error-minimal dl-conflict dl-hwcaps dl-hwcaps_split dl-hwcaps-subdirs \ + dl-usage all-rtld-routines = $(rtld-routines) $(sysdep-rtld-routines) CFLAGS-dl-runtime.c += -fexceptions -fasynchronous-unwind-tables @@ -212,14 +213,14 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \ tst-audit14 tst-audit15 tst-audit16 \ tst-single_threaded tst-single_threaded-pthread \ - tst-tls-ie tst-tls-ie-dlmopen \ - argv0test + tst-tls-ie tst-tls-ie-dlmopen argv0test \ + tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ tst-tls3 tst-tls6 tst-tls7 tst-tls8 tst-dlmopen2 \ tst-ptrguard1 tst-stackguard1 tst-libc_dlvsym \ - tst-create_format1 tst-tls-surplus + tst-create_format1 tst-tls-surplus tst-dl-hwcaps_split tests-container += tst-pldd tst-dlopen-tlsmodid-container \ tst-dlopen-self-container test-srcs = tst-pathopt @@ -331,7 +332,10 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-single_threaded-mod3 tst-single_threaded-mod4 \ tst-tls-ie-mod0 tst-tls-ie-mod1 tst-tls-ie-mod2 \ tst-tls-ie-mod3 tst-tls-ie-mod4 tst-tls-ie-mod5 \ - tst-tls-ie-mod6 + tst-tls-ie-mod6 libmarkermod1-1 libmarkermod1-2 libmarkermod1-3 \ + libmarkermod2-1 libmarkermod2-2 \ + libmarkermod3-1 libmarkermod3-2 libmarkermod3-3 \ + libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \ # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. @@ -1814,3 +1818,60 @@ $(objpfx)argv0test.out: tst-rtld-argv0.sh $(objpfx)ld.so \ '$(test-wrapper-env)' '$(run_program_env)' \ '$(rpath-link)' 'test-argv0' > $@; \ $(evaluate-test) + +# A list containing the name of the most likely searched subdirectory +# of the glibc-hwcaps directory, for each supported architecture (in +# other words, the oldest hardware level recognized by the +# glibc-hwcaps mechanism for this architecture). Used to obtain test +# coverage for some glibc-hwcaps tests for the widest possible range +# of systems. +glibc-hwcaps-first-subdirs-for-tests = + +# The test modules are parameterized by preprocessor macros. +LDFLAGS-libmarkermod1-1.so += -Wl,-soname,libmarkermod1.so +LDFLAGS-libmarkermod2-1.so += -Wl,-soname,libmarkermod2.so +LDFLAGS-libmarkermod3-1.so += -Wl,-soname,libmarkermod3.so +LDFLAGS-libmarkermod4-1.so += -Wl,-soname,libmarkermod4.so +$(objpfx)libmarkermod%.os : markermodMARKER-VALUE.c + $(compile-command.c) \ + -DMARKER=marker$(firstword $(subst -, ,$*)) \ + -DVALUE=$(lastword $(subst -, ,$*)) +$(objpfx)libmarkermod1.so: $(objpfx)libmarkermod1-1.so + cp $< $@ +$(objpfx)libmarkermod2.so: $(objpfx)libmarkermod2-1.so + cp $< $@ +$(objpfx)libmarkermod3.so: $(objpfx)libmarkermod3-1.so + cp $< $@ +$(objpfx)libmarkermod4.so: $(objpfx)libmarkermod4-1.so + cp $< $@ + +# tst-glibc-hwcaps-prepend checks that --glibc-hwcaps-prepend is +# preferred over auto-detected subdirectories. +$(objpfx)tst-glibc-hwcaps-prepend: $(objpfx)libmarkermod1-1.so +$(objpfx)glibc-hwcaps/prepend-markermod1/libmarkermod1.so: \ + $(objpfx)libmarkermod1-2.so + $(make-target-directory) + cp $< $@ +$(objpfx)glibc-hwcaps/%/libmarkermod1.so: $(objpfx)libmarkermod1-3.so + $(make-target-directory) + cp $< $@ +$(objpfx)tst-glibc-hwcaps-prepend.out: \ + $(objpfx)tst-glibc-hwcaps-prepend $(objpfx)libmarkermod1.so \ + $(patsubst %,$(objpfx)glibc-hwcaps/%/libmarkermod1.so,prepend-markermod1 \ + $(glibc-hwcaps-first-subdirs-for-tests)) + $(test-wrapper) $(rtld-prefix) \ + --glibc-hwcaps-prepend prepend-markermod1 \ + $< > $@; \ + $(evaluate-test) + +# tst-glibc-hwcaps-mask checks that --glibc-hwcaps-mask can be used to +# suppress all auto-detected subdirectories. +$(objpfx)tst-glibc-hwcaps-mask: $(objpfx)libmarkermod1-1.so +$(objpfx)tst-glibc-hwcaps-mask.out: \ + $(objpfx)tst-glibc-hwcaps-mask $(objpfx)libmarkermod1.so \ + $(patsubst %,$(objpfx)glibc-hwcaps/%/libmarkermod1.so,\ + $(glibc-hwcaps-first-subdirs-for-tests)) + $(test-wrapper) $(rtld-prefix) \ + --glibc-hwcaps-mask does-not-exist \ + $< > $@; \ + $(evaluate-test) diff --git a/elf/dl-hwcaps-subdirs.c b/elf/dl-hwcaps-subdirs.c new file mode 100644 index 0000000..60c6d59 --- /dev/null +++ b/elf/dl-hwcaps-subdirs.c @@ -0,0 +1,29 @@ +/* Architecture-specific glibc-hwcaps subdirectories. Generic version. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <dl-hwcaps.h> + +/* In the generic version, there are no subdirectories defined. */ + +const char _dl_hwcaps_subdirs[] = ""; + +uint32_t +_dl_hwcaps_subdirs_active (void) +{ + return 0; +} diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c index 44dbac0..f611f3a 100644 --- a/elf/dl-hwcaps.c +++ b/elf/dl-hwcaps.c @@ -26,20 +26,97 @@ #include <dl-procinfo.h> #include <dl-hwcaps.h> +/* This is the result of counting the substrings in a colon-separated + hwcaps string. */ +struct hwcaps_counts +{ + /* Number of substrings. */ + size_t count; + + /* Sum of the individual substring lengths (without separators or + null terminators). */ + size_t total_length; + + /* Maximum length of an individual substring. */ + size_t maximum_length; +}; + +/* Update *COUNTS according to the contents of HWCAPS. Skip over + entries whose bit is not set in MASK. */ +static void +update_hwcaps_counts (struct hwcaps_counts *counts, const char *hwcaps, + uint32_t bitmask, const char *mask) +{ + struct dl_hwcaps_split_masked sp; + _dl_hwcaps_split_masked_init (&sp, hwcaps, bitmask, mask); + while (_dl_hwcaps_split_masked (&sp)) + { + ++counts->count; + counts->total_length += sp.split.length; + if (sp.split.length > counts->maximum_length) + counts->maximum_length = sp.split.length; + } +} + +/* State for copy_hwcaps. Must be initialized to point to + the storage areas for the array and the strings themselves. */ +struct copy_hwcaps +{ + struct r_strlenpair *next_pair; + char *next_string; +}; + +/* Copy HWCAPS into the string pairs and strings, advancing *TARGET. + Skip over entries whose bit is not set in MASK. */ +static void +copy_hwcaps (struct copy_hwcaps *target, const char *hwcaps, + uint32_t bitmask, const char *mask) +{ + struct dl_hwcaps_split_masked sp; + _dl_hwcaps_split_masked_init (&sp, hwcaps, bitmask, mask); + while (_dl_hwcaps_split_masked (&sp)) + { + target->next_pair->str = target->next_string; + char *slash = __mempcpy (__mempcpy (target->next_string, + GLIBC_HWCAPS_PREFIX, + strlen (GLIBC_HWCAPS_PREFIX)), + sp.split.segment, sp.split.length); + *slash = '/'; + target->next_pair->len + = strlen (GLIBC_HWCAPS_PREFIX) + sp.split.length + 1; + ++target->next_pair; + target->next_string = slash + 1; + } +} + /* Return an array of useful/necessary hardware capability names. */ const struct r_strlenpair * -_dl_important_hwcaps (size_t *sz, size_t *max_capstrlen) +_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; - size_t total; struct r_strlenpair *result; struct r_strlenpair *rp; char *cp; + /* glibc-hwcaps subdirectories. These are exempted from the power + set construction below. */ + 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); + update_hwcaps_counts (&hwcaps_counts, _dl_hwcaps_subdirs, + hwcaps_subdirs_active, glibc_hwcaps_mask); + + /* Each hwcaps subdirectory has a GLIBC_HWCAPS_PREFIX string prefix + and a "/" suffix once stored in the result. */ + 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) @@ -74,10 +151,10 @@ _dl_important_hwcaps (size_t *sz, size_t *max_capstrlen) /* Determine the total size of all strings together. */ if (cnt == 1) - total = temp[0].len + 1; + total += temp[0].len + 1; else { - total = temp[0].len + temp[cnt - 1].len + 2; + total += temp[0].len + temp[cnt - 1].len + 2; if (cnt > 2) { total <<= 1; @@ -94,26 +171,48 @@ _dl_important_hwcaps (size_t *sz, size_t *max_capstrlen) } } - /* The result structure: we use a very compressed way to store the - various combinations of capability names. */ - *sz = 1 << cnt; - result = (struct r_strlenpair *) malloc (*sz * sizeof (*result) + total); - if (result == NULL) + *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. */ + struct r_strlenpair *overall_result + = malloc (*sz * sizeof (*result) + total); + if (overall_result == NULL) _dl_signal_error (ENOMEM, NULL, NULL, N_("cannot create capability list")); + /* Fill in the glibc-hwcaps subdirectories. */ + { + struct copy_hwcaps target; + target.next_pair = overall_result; + target.next_string = (char *) (overall_result + *sz); + 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 = (char *) (result + *sz); + result[0].str = cp; result[0].len = temp[0].len + 1; - result[1].str = (char *) (result + *sz); + result[1].str = cp; result[1].len = 0; - cp = __mempcpy ((char *) (result + *sz), temp[0].str, temp[0].len); + cp = __mempcpy (cp, temp[0].str, temp[0].len); *cp = '/'; - *sz = 2; - *max_capstrlen = result[0].len; + if (result[0].len > hwcaps_counts.maximum_length) + *max_capstrlen = result[0].len; + else + *max_capstrlen = hwcaps_counts.maximum_length; - return result; + return overall_result; } /* Fill in the information. This follows the following scheme @@ -124,7 +223,7 @@ _dl_important_hwcaps (size_t *sz, size_t *max_capstrlen) #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 = (char *) (result + *sz); + result[1].str = result[0].str = cp; #define add(idx) \ cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1); if (cnt == 2) @@ -191,7 +290,10 @@ _dl_important_hwcaps (size_t *sz, size_t *max_capstrlen) while (--n != 0); /* The maximum string length. */ - *max_capstrlen = result[0].len; + if (result[0].len > hwcaps_counts.maximum_length) + *max_capstrlen = result[0].len; + else + *max_capstrlen = hwcaps_counts.maximum_length; - return result; + return overall_result; } diff --git a/elf/dl-hwcaps.h b/elf/dl-hwcaps.h index b66da59..ab39d8a 100644 --- a/elf/dl-hwcaps.h +++ b/elf/dl-hwcaps.h @@ -16,6 +16,11 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ +#ifndef _DL_HWCAPS_H +#define _DL_HWCAPS_H + +#include <stdint.h> + #include <elf/dl-tunables.h> #if HAVE_TUNABLES @@ -28,3 +33,103 @@ # define GET_HWCAP_MASK() (0) # endif #endif + +#define GLIBC_HWCAPS_SUBDIRECTORY "glibc-hwcaps" +#define GLIBC_HWCAPS_PREFIX GLIBC_HWCAPS_SUBDIRECTORY "/" + +/* Used by _dl_hwcaps_split below, to split strings at ':' + separators. */ +struct dl_hwcaps_split +{ + const char *segment; /* Start of the current segment. */ + size_t length; /* Number of bytes until ':' or NUL. */ +}; + +/* Prepare *S to parse SUBJECT, for future _dl_hwcaps_split calls. If + SUBJECT is NULL, it is treated as the empty string. */ +static inline void +_dl_hwcaps_split_init (struct dl_hwcaps_split *s, const char *subject) +{ + s->segment = subject; + /* The initial call to _dl_hwcaps_split will not skip anything. */ + s->length = 0; +} + +/* Extract the next non-empty string segment, up to ':' or the null + terminator. Return true if one more segment was found, or false if + the end of the string was reached. On success, S->segment is the + start of the segment found, and S->length is its length. + (Typically, S->segment[S->length] is not null.) */ +_Bool _dl_hwcaps_split (struct dl_hwcaps_split *s) attribute_hidden; + +/* Similar to dl_hwcaps_split, but with bit-based and name-based + masking. */ +struct dl_hwcaps_split_masked +{ + struct dl_hwcaps_split split; + + /* For used by the iterator implementation. */ + const char *mask; + uint32_t bitmask; +}; + +/* Prepare *S for iteration with _dl_hwcaps_split_masked. Only HWCAP + names in SUBJECT whose bit is set in BITMASK and whose name is in + MASK will be returned. SUBJECT must not contain empty HWCAP names. + If MASK is NULL, no name-based masking is applied. Likewise for + BITMASK if BITMASK is -1 (infinite number of bits). */ +static inline void +_dl_hwcaps_split_masked_init (struct dl_hwcaps_split_masked *s, + const char *subject, + uint32_t bitmask, const char *mask) +{ + _dl_hwcaps_split_init (&s->split, subject); + s->bitmask = bitmask; + s->mask = mask; +} + +/* Like _dl_hwcaps_split, but apply masking. */ +_Bool _dl_hwcaps_split_masked (struct dl_hwcaps_split_masked *s) + attribute_hidden; + +/* Returns true if the colon-separated HWCAP list HWCAPS contains the + capability NAME (with length NAME_LENGTH). If HWCAPS is NULL, the + function returns true. */ +_Bool _dl_hwcaps_contains (const char *hwcaps, const char *name, + size_t name_length) attribute_hidden; + +/* Colon-separated string of glibc-hwcaps subdirectories, without the + "glibc-hwcaps/" prefix. The most preferred subdirectory needs to + be listed first. Up to 32 subdirectories are supported, limited by + the width of the uint32_t mask. */ +extern const char _dl_hwcaps_subdirs[] attribute_hidden; + +/* Returns a bitmap of active subdirectories in _dl_hwcaps_subdirs. + Bit 0 (the LSB) corresponds to the first substring in + _dl_hwcaps_subdirs, bit 1 to the second substring, and so on. + There is no direct correspondence between HWCAP bitmasks and this + bitmask. */ +uint32_t _dl_hwcaps_subdirs_active (void) attribute_hidden; + +/* Returns a bitmask that marks the last ACTIVE subdirectories in a + _dl_hwcaps_subdirs_active string (containing SUBDIRS directories in + total) as active. Intended for use in _dl_hwcaps_subdirs_active + implementations (if a contiguous tail of the list in + _dl_hwcaps_subdirs is selected). */ +static inline uint32_t +_dl_hwcaps_subdirs_build_bitmask (int subdirs, int active) +{ + /* Leading subdirectories that are not active. */ + int inactive = subdirs - active; + if (inactive == 32) + return 0; + + uint32_t mask; + if (subdirs != 32) + mask = (1U << subdirs) - 1; + else + mask = -1; + return mask ^ ((1U << inactive) - 1); +} + +#endif /* _DL_HWCAPS_H */ diff --git a/elf/dl-hwcaps_split.c b/elf/dl-hwcaps_split.c new file mode 100644 index 0000000..95225e9 --- /dev/null +++ b/elf/dl-hwcaps_split.c @@ -0,0 +1,77 @@ +/* Hardware capability support for run-time dynamic loader. String splitting. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <dl-hwcaps.h> +#include <stdbool.h> +#include <string.h> + +_Bool +_dl_hwcaps_split (struct dl_hwcaps_split *s) +{ + if (s->segment == NULL) + return false; + + /* Skip over the previous segment. */ + s->segment += s->length; + + /* Consume delimiters. This also avoids returning an empty + segment. */ + while (*s->segment == ':') + ++s->segment; + if (*s->segment == '\0') + return false; + + /* This could use strchrnul, but we would have to link the function + into ld.so for that. */ + const char *colon = strchr (s->segment, ':'); + if (colon == NULL) + s->length = strlen (s->segment); + else + s->length = colon - s->segment; + return true; +} + +_Bool +_dl_hwcaps_split_masked (struct dl_hwcaps_split_masked *s) +{ + while (true) + { + if (!_dl_hwcaps_split (&s->split)) + return false; + bool active = s->bitmask & 1; + s->bitmask >>= 1; + if (active && _dl_hwcaps_contains (s->mask, + s->split.segment, s->split.length)) + return true; + } +} + +_Bool +_dl_hwcaps_contains (const char *hwcaps, const char *name, size_t name_length) +{ + if (hwcaps == NULL) + return true; + + struct dl_hwcaps_split split; + _dl_hwcaps_split_init (&split, hwcaps); + while (_dl_hwcaps_split (&split)) + if (split.length == name_length + && memcmp (split.segment, name, name_length) == 0) + return true; + return false; +} diff --git a/elf/dl-load.c b/elf/dl-load.c index f3201e7..9020f16 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -682,7 +682,9 @@ cache_rpath (struct link_map *l, void -_dl_init_paths (const char *llp, const char *source) +_dl_init_paths (const char *llp, const char *source, + const char *glibc_hwcaps_prepend, + const char *glibc_hwcaps_mask) { size_t idx; const char *strp; @@ -697,7 +699,8 @@ _dl_init_paths (const char *llp, const char *source) #ifdef SHARED /* Get the capabilities. */ - capstr = _dl_important_hwcaps (&ncapstr, &max_capstrlen); + capstr = _dl_important_hwcaps (glibc_hwcaps_prepend, glibc_hwcaps_mask, + &ncapstr, &max_capstrlen); #endif /* First set up the rest of the default search directory entries. */ diff --git a/elf/dl-main.h b/elf/dl-main.h index b51256d..566713a 100644 --- a/elf/dl-main.h +++ b/elf/dl-main.h @@ -84,6 +84,14 @@ struct dl_main_state /* The preload list passed as a command argument. */ const char *preloadarg; + /* Additional glibc-hwcaps subdirectories to search first. + Colon-separated list. */ + const char *glibc_hwcaps_prepend; + + /* Mask for the internal glibc-hwcaps subdirectories. + Colon-separated list. */ + const char *glibc_hwcaps_mask; + enum rtld_mode mode; /* True if any of the debugging options is enabled. */ @@ -98,7 +106,8 @@ struct dl_main_state static inline void call_init_paths (const struct dl_main_state *state) { - _dl_init_paths (state->library_path, state->library_path_source); + _dl_init_paths (state->library_path, state->library_path_source, + state->glibc_hwcaps_prepend, state->glibc_hwcaps_mask); } /* Print ld.so usage information and exit. */ diff --git a/elf/dl-support.c b/elf/dl-support.c index 15e6d78..250e4cd 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -324,7 +324,10 @@ _dl_non_dynamic_init (void) /* Initialize the data structures for the search paths for shared objects. */ - _dl_init_paths (getenv ("LD_LIBRARY_PATH"), "LD_LIBRARY_PATH"); + _dl_init_paths (getenv ("LD_LIBRARY_PATH"), "LD_LIBRARY_PATH", + /* No glibc-hwcaps selection support in statically + linked binaries. */ + NULL, NULL); /* Remember the last search directory added at startup. */ _dl_init_all_dirs = GL(dl_all_dirs); diff --git a/elf/dl-usage.c b/elf/dl-usage.c index 796ad38..e22a9c3 100644 --- a/elf/dl-usage.c +++ b/elf/dl-usage.c @@ -83,7 +83,7 @@ print_search_path_for_help (struct dl_main_state *state) { if (__rtld_search_dirs.dirs == NULL) /* The run-time search paths have not yet been initialized. */ - _dl_init_paths (state->library_path, state->library_path_source); + call_init_paths (state); _dl_printf ("\nShared library search path:\n"); @@ -132,6 +132,67 @@ print_hwcap_1_finish (bool *first) _dl_printf (")\n"); } +/* Print the header for print_hwcaps_subdirectories. */ +static void +print_hwcaps_subdirectories_header (bool *nothing_printed) +{ + if (*nothing_printed) + { + _dl_printf ("\n\ +Subdirectories of glibc-hwcaps directories, in priority order:\n"); + *nothing_printed = false; + } +} + +/* Print the HWCAP name itself, indented. */ +static void +print_hwcaps_subdirectories_name (const struct dl_hwcaps_split *split) +{ + _dl_write (STDOUT_FILENO, " ", 2); + _dl_write (STDOUT_FILENO, split->segment, split->length); +} + +/* Print the list of recognized glibc-hwcaps subdirectories. */ +static void +print_hwcaps_subdirectories (const struct dl_main_state *state) +{ + bool nothing_printed = true; + struct dl_hwcaps_split split; + + /* The prepended glibc-hwcaps subdirectories. */ + _dl_hwcaps_split_init (&split, state->glibc_hwcaps_prepend); + while (_dl_hwcaps_split (&split)) + { + print_hwcaps_subdirectories_header (¬hing_printed); + print_hwcaps_subdirectories_name (&split); + bool first = true; + print_hwcap_1 (&first, true, "searched"); + print_hwcap_1_finish (&first); + } + + /* The built-in glibc-hwcaps subdirectories. Do the filtering + manually, so that more precise diagnostics are possible. */ + uint32_t mask = _dl_hwcaps_subdirs_active (); + _dl_hwcaps_split_init (&split, _dl_hwcaps_subdirs); + while (_dl_hwcaps_split (&split)) + { + print_hwcaps_subdirectories_header (¬hing_printed); + print_hwcaps_subdirectories_name (&split); + bool first = true; + print_hwcap_1 (&first, mask & 1, "supported"); + bool listed = _dl_hwcaps_contains (state->glibc_hwcaps_mask, + split.segment, split.length); + print_hwcap_1 (&first, !listed, "masked"); + print_hwcap_1 (&first, (mask & 1) && listed, "searched"); + print_hwcap_1_finish (&first); + mask >>= 1; + } + + if (nothing_printed) + _dl_printf ("\n\ +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 @@ -186,6 +247,10 @@ setting environment variables (which would be inherited by subprocesses).\n\ --inhibit-cache Do not use " LD_SO_CACHE "\n\ --library-path PATH use given PATH instead of content of the environment\n\ variable LD_LIBRARY_PATH\n\ + --glibc-hwcaps-prepend LIST\n\ + search glibc-hwcaps subdirectories in LIST\n\ + --glibc-hwcaps-mask LIST\n\ + only search built-in subdirectories if in LIST\n\ --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ in LIST\n\ --audit LIST use objects named in LIST as auditors\n\ @@ -198,6 +263,7 @@ 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); } diff --git a/elf/markermodMARKER-VALUE.c b/elf/markermodMARKER-VALUE.c new file mode 100644 index 0000000..99bdcf7 --- /dev/null +++ b/elf/markermodMARKER-VALUE.c @@ -0,0 +1,29 @@ +/* Source file template for building shared objects with marker functions. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +/* MARKER and VALUE must be set on the compiler command line. */ + +#ifndef MARKER +# error MARKER not defined +#endif + +int +MARKER (void) +{ + return VALUE; +} @@ -290,6 +290,8 @@ dl_main_state_init (struct dl_main_state *state) state->library_path_source = NULL; state->preloadlist = NULL; state->preloadarg = NULL; + state->glibc_hwcaps_prepend = NULL; + state->glibc_hwcaps_mask = NULL; state->mode = rtld_mode_normal; state->any_debug = false; state->version_info = false; @@ -1257,6 +1259,22 @@ dl_main (const ElfW(Phdr) *phdr, _dl_argc -= 2; _dl_argv += 2; } + else if (strcmp (_dl_argv[1], "--glibc-hwcaps-prepend") == 0 + && _dl_argc > 2) + { + state.glibc_hwcaps_prepend = _dl_argv[2]; + _dl_skip_args += 2; + _dl_argc -= 2; + _dl_argv += 2; + } + else if (strcmp (_dl_argv[1], "--glibc-hwcaps-mask") == 0 + && _dl_argc > 2) + { + state.glibc_hwcaps_mask = _dl_argv[2]; + _dl_skip_args += 2; + _dl_argc -= 2; + _dl_argv += 2; + } else if (strcmp (_dl_argv[1], "--help") == 0) { state.mode = rtld_mode_help; diff --git a/elf/tst-dl-hwcaps_split.c b/elf/tst-dl-hwcaps_split.c new file mode 100644 index 0000000..3641594 --- /dev/null +++ b/elf/tst-dl-hwcaps_split.c @@ -0,0 +1,148 @@ +/* Unit tests for dl-hwcaps.c. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <array_length.h> +#include <dl-hwcaps.h> +#include <string.h> +#include <support/check.h> + +static void +check_split_masked (const char *input, int32_t bitmask, const char *mask, + const char *expected[], size_t expected_length) +{ + struct dl_hwcaps_split_masked split; + _dl_hwcaps_split_masked_init (&split, input, bitmask, mask); + size_t index = 0; + while (_dl_hwcaps_split_masked (&split)) + { + TEST_VERIFY_EXIT (index < expected_length); + TEST_COMPARE_BLOB (expected[index], strlen (expected[index]), + split.split.segment, split.split.length); + ++index; + } + TEST_COMPARE (index, expected_length); +} + +static void +check_split (const char *input, + const char *expected[], size_t expected_length) +{ + struct dl_hwcaps_split split; + _dl_hwcaps_split_init (&split, input); + size_t index = 0; + while (_dl_hwcaps_split (&split)) + { + TEST_VERIFY_EXIT (index < expected_length); + TEST_COMPARE_BLOB (expected[index], strlen (expected[index]), + split.segment, split.length); + ++index; + } + TEST_COMPARE (index, expected_length); + + /* Reuse the test cases with masking that does not actually remove + anything. */ + check_split_masked (input, -1, NULL, expected, expected_length); + check_split_masked (input, -1, input, expected, expected_length); +} + +static int +do_test (void) +{ + /* Splitting tests, without masking. */ + check_split (NULL, NULL, 0); + check_split ("", NULL, 0); + check_split (":", NULL, 0); + check_split ("::", NULL, 0); + + { + const char *expected[] = { "first" }; + check_split ("first", expected, array_length (expected)); + check_split (":first", expected, array_length (expected)); + check_split ("first:", expected, array_length (expected)); + check_split (":first:", expected, array_length (expected)); + } + + { + const char *expected[] = { "first", "second" }; + check_split ("first:second", expected, array_length (expected)); + check_split ("first::second", expected, array_length (expected)); + check_split (":first:second", expected, array_length (expected)); + check_split ("first:second:", expected, array_length (expected)); + check_split (":first:second:", expected, array_length (expected)); + } + + /* Splitting tests with masking. */ + { + const char *expected[] = { "first" }; + check_split_masked ("first", 3, "first:second", + expected, array_length (expected)); + check_split_masked ("first:second", 3, "first:", + expected, array_length (expected)); + check_split_masked ("first:second", 1, NULL, + expected, array_length (expected)); + } + { + const char *expected[] = { "second" }; + check_split_masked ("first:second", 3, "second", + expected, array_length (expected)); + check_split_masked ("first:second:third", -1, "second:", + expected, array_length (expected)); + check_split_masked ("first:second", 2, NULL, + expected, array_length (expected)); + check_split_masked ("first:second:third", 2, "first:second", + expected, array_length (expected)); + } + + /* Tests for _dl_hwcaps_contains. */ + TEST_VERIFY (_dl_hwcaps_contains (NULL, "first", strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains (NULL, "", 0)); + TEST_VERIFY (! _dl_hwcaps_contains ("", "first", strlen ("first"))); + TEST_VERIFY (! _dl_hwcaps_contains ("firs", "first", strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains ("firs", "first", strlen ("first") - 1)); + for (int i = 0; i < strlen ("first"); ++i) + TEST_VERIFY (! _dl_hwcaps_contains ("first", "first", i)); + TEST_VERIFY (_dl_hwcaps_contains ("first", "first", strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains ("first:", "first", strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains ("first:second", + "first", strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains (":first:second", "first", + strlen ("first"))); + TEST_VERIFY (_dl_hwcaps_contains ("first:second", "second", + strlen ("second"))); + TEST_VERIFY (_dl_hwcaps_contains ("first:second:", "second", + strlen ("second"))); + TEST_VERIFY (_dl_hwcaps_contains ("first::second:", "second", + strlen ("second"))); + TEST_VERIFY (_dl_hwcaps_contains ("first:second::", "second", + strlen ("second"))); + for (int i = 0; i < strlen ("second"); ++i) + { + TEST_VERIFY (!_dl_hwcaps_contains ("first:second", "second", i)); + TEST_VERIFY (!_dl_hwcaps_contains ("first:second:", "second", i)); + TEST_VERIFY (!_dl_hwcaps_contains ("first:second::", "second", i)); + TEST_VERIFY (!_dl_hwcaps_contains ("first::second", "second", i)); + } + + return 0; +} + +#include <support/test-driver.c> + +/* Rebuild the sources here because the object file is built for + inclusion into the dynamic loader. */ +#include "dl-hwcaps_split.c" diff --git a/elf/tst-glibc-hwcaps-mask.c b/elf/tst-glibc-hwcaps-mask.c new file mode 100644 index 0000000..27b09b3 --- /dev/null +++ b/elf/tst-glibc-hwcaps-mask.c @@ -0,0 +1,31 @@ +/* Test that --glibc-hwcaps-mask works. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <support/check.h> + +extern int marker1 (void); + +static int +do_test (void) +{ + /* The marker1 function in elf/markermod1.so returns 1. */ + TEST_COMPARE (marker1 (), 1); + return 0; +} + +#include <support/test-driver.c> diff --git a/elf/tst-glibc-hwcaps-prepend.c b/elf/tst-glibc-hwcaps-prepend.c new file mode 100644 index 0000000..57d7319 --- /dev/null +++ b/elf/tst-glibc-hwcaps-prepend.c @@ -0,0 +1,32 @@ +/* Test that --glibc-hwcaps-prepend works. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <support/check.h> + +extern int marker1 (void); + +static int +do_test (void) +{ + /* The marker1 function in + glibc-hwcaps/prepend-markermod1/markermod1.so returns 2. */ + TEST_COMPARE (marker1 (), 2); + return 0; +} + +#include <support/test-driver.c> diff --git a/elf/tst-glibc-hwcaps.c b/elf/tst-glibc-hwcaps.c new file mode 100644 index 0000000..28f47cf --- /dev/null +++ b/elf/tst-glibc-hwcaps.c @@ -0,0 +1,28 @@ +/* Stub test for glibc-hwcaps. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> + +static int +do_test (void) +{ + puts ("info: generic tst-glibc-hwcaps (tests nothing)"); + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index b1da03c..7135fa9 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -1055,8 +1055,13 @@ extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns) attribute_hidden; /* Initialize the basic data structure for the search paths. SOURCE - is either "LD_LIBRARY_PATH" or "--library-path". */ -extern void _dl_init_paths (const char *library_path, const char *source) + is either "LD_LIBRARY_PATH" or "--library-path". + GLIBC_HWCAPS_PREPEND adds additional glibc-hwcaps subdirectories to + search. GLIBC_HWCAPS_MASK is used to filter the built-in + subdirectories if not NULL. */ +extern void _dl_init_paths (const char *library_path, const char *source, + const char *glibc_hwcaps_prepend, + const char *glibc_hwcaps_mask) attribute_hidden; /* Gather the information needed to install the profiling tables and start @@ -1080,9 +1085,14 @@ extern void _dl_show_auxv (void) attribute_hidden; extern char *_dl_next_ld_env_entry (char ***position) attribute_hidden; /* Return an array with the names of the important hardware - capabilities. The length of the array is written to *SZ, and the - maximum of all strings length is written to *MAX_CAPSTRLEN. */ -const struct r_strlenpair *_dl_important_hwcaps (size_t *sz, + capabilities. PREPEND is a colon-separated list of glibc-hwcaps + directories to search first. MASK is a colon-separated list used + to filter the built-in glibc-hwcaps subdirectories. The length of + the array is written to *SZ, and the maximum of all strings length + is written to *MAX_CAPSTRLEN. */ +const struct r_strlenpair *_dl_important_hwcaps (const char *prepend, + const char *mask, + size_t *sz, size_t *max_capstrlen) attribute_hidden; |