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Diffstat (limited to 'newlib/libc/sys/linux/dl/dl-profile.c')
| -rw-r--r-- | newlib/libc/sys/linux/dl/dl-profile.c | 539 |
1 files changed, 0 insertions, 539 deletions
diff --git a/newlib/libc/sys/linux/dl/dl-profile.c b/newlib/libc/sys/linux/dl/dl-profile.c deleted file mode 100644 index 52c533f5f..000000000 --- a/newlib/libc/sys/linux/dl/dl-profile.c +++ /dev/null @@ -1,539 +0,0 @@ -/* Profiling of shared libraries. - Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. - Based on the BSD mcount implementation. - - 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, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include <errno.h> -#include <fcntl.h> -#include <limits.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <ldsodefs.h> -#include <sys/gmon.h> -#include <sys/gmon_out.h> -#include <sys/mman.h> -#include <sys/param.h> -#include <sys/stat.h> -#include <atomicity.h> -#include <config.h> - -/* The LD_PROFILE feature has to be implemented different to the - normal profiling using the gmon/ functions. The problem is that an - arbitrary amount of processes simulataneously can be run using - profiling and all write the results in the same file. To provide - this mechanism one could implement a complicated mechanism to merge - the content of two profiling runs or one could extend the file - format to allow more than one data set. For the second solution we - would have the problem that the file can grow in size beyond any - limit and both solutions have the problem that the concurrency of - writing the results is a big problem. - - Another much simpler method is to use mmap to map the same file in - all using programs and modify the data in the mmap'ed area and so - also automatically on the disk. Using the MAP_SHARED option of - mmap(2) this can be done without big problems in more than one - file. - - This approach is very different from the normal profiling. We have - to use the profiling data in exactly the way they are expected to - be written to disk. But the normal format used by gprof is not usable - to do this. It is optimized for size. It writes the tags as single - bytes but this means that the following 32/64 bit values are - unaligned. - - Therefore we use a new format. This will look like this - - 0 1 2 3 <- byte is 32 bit word - 0000 g m o n - 0004 *version* <- GMON_SHOBJ_VERSION - 0008 00 00 00 00 - 000c 00 00 00 00 - 0010 00 00 00 00 - - 0014 *tag* <- GMON_TAG_TIME_HIST - 0018 ?? ?? ?? ?? - ?? ?? ?? ?? <- 32/64 bit LowPC - 0018+A ?? ?? ?? ?? - ?? ?? ?? ?? <- 32/64 bit HighPC - 0018+2*A *histsize* - 001c+2*A *profrate* - 0020+2*A s e c o - 0024+2*A n d s \0 - 0028+2*A \0 \0 \0 \0 - 002c+2*A \0 \0 \0 - 002f+2*A s - - 0030+2*A ?? ?? ?? ?? <- Count data - ... ... - 0030+2*A+K ?? ?? ?? ?? - - 0030+2*A+K *tag* <- GMON_TAG_CG_ARC - 0034+2*A+K *lastused* - 0038+2*A+K ?? ?? ?? ?? - ?? ?? ?? ?? <- FromPC#1 - 0038+3*A+K ?? ?? ?? ?? - ?? ?? ?? ?? <- ToPC#1 - 0038+4*A+K ?? ?? ?? ?? <- Count#1 - ... ... ... - 0038+(2*(CN-1)+2)*A+(CN-1)*4+K ?? ?? ?? ?? - ?? ?? ?? ?? <- FromPC#CGN - 0038+(2*(CN-1)+3)*A+(CN-1)*4+K ?? ?? ?? ?? - ?? ?? ?? ?? <- ToPC#CGN - 0038+(2*CN+2)*A+(CN-1)*4+K ?? ?? ?? ?? <- Count#CGN - - We put (for now?) no basic block information in the file since this would - introduce rase conditions among all the processes who want to write them. - - `K' is the number of count entries which is computed as - - textsize / HISTFRACTION - - `CG' in the above table is the number of call graph arcs. Normally, - the table is sparse and the profiling code writes out only the those - entries which are really used in the program run. But since we must - not extend this table (the profiling file) we'll keep them all here. - So CN can be executed in advance as - - MINARCS <= textsize*(ARCDENSITY/100) <= MAXARCS - - Now the remaining question is: how to build the data structures we can - work with from this data. We need the from set and must associate the - froms with all the associated tos. We will do this by constructing this - data structures at the program start. To do this we'll simply visit all - entries in the call graph table and add it to the appropriate list. */ - -extern int __profile_frequency (void); - -/* We define a special type to address the elements of the arc table. - This is basically the `gmon_cg_arc_record' format but it includes - the room for the tag and it uses real types. */ -struct here_cg_arc_record - { - uintptr_t from_pc; - uintptr_t self_pc; - uint32_t count; - } __attribute__ ((packed)); - -static struct here_cg_arc_record *data; - -/* Nonzero if profiling is under way. */ -static int running; - -/* This is the number of entry which have been incorporated in the toset. */ -static uint32_t narcs; -/* This is a pointer to the object representing the number of entries - currently in the mmaped file. At no point of time this has to be the - same as NARCS. If it is equal all entries from the file are in our - lists. */ -static volatile uint32_t *narcsp; - -static volatile uint16_t *kcount; -static size_t kcountsize; - -struct here_fromstruct - { - struct here_cg_arc_record volatile *here; - uint16_t link; - }; - -static volatile uint16_t *tos; - -static struct here_fromstruct *froms; -static uint32_t fromlimit; -static volatile uint32_t fromidx; - -static uintptr_t lowpc; -static size_t textsize; -static unsigned int hashfraction; -static unsigned int log_hashfraction; - - - -/* Set up profiling data to profile object desribed by MAP. The output - file is found (or created) in OUTPUT_DIR. */ -void -internal_function -_dl_start_profile (struct link_map *map, const char *output_dir) -{ - char *filename; - int fd; - struct stat64 st; - const ElfW(Phdr) *ph; - ElfW(Addr) mapstart = ~((ElfW(Addr)) 0); - ElfW(Addr) mapend = 0; - struct gmon_hdr gmon_hdr; - struct gmon_hist_hdr hist_hdr; - char *hist, *cp, *tmp; - size_t idx; - size_t tossize; - size_t fromssize; - uintptr_t highpc; - struct gmon_hdr *addr = NULL; - off_t expected_size; - /* See profil(2) where this is described. */ - int s_scale; -#define SCALE_1_TO_1 0x10000L - - /* Compute the size of the sections which contain program code. */ - for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph) - if (ph->p_type == PT_LOAD && (ph->p_flags & PF_X)) - { - ElfW(Addr) start = (ph->p_vaddr & ~(_dl_pagesize - 1)); - ElfW(Addr) end = ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1) - & ~(_dl_pagesize - 1)); - - if (start < mapstart) - mapstart = start; - if (end > mapend) - mapend = end; - } - - /* Now we can compute the size of the profiling data. This is done - with the same formulars as in `monstartup' (see gmon.c). */ - running = 0; - lowpc = ROUNDDOWN (mapstart + map->l_addr, - HISTFRACTION * sizeof (HISTCOUNTER)); - highpc = ROUNDUP (mapend + map->l_addr, - HISTFRACTION * sizeof (HISTCOUNTER)); - textsize = highpc - lowpc; - kcountsize = textsize / HISTFRACTION; - hashfraction = HASHFRACTION; - if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) - /* If HASHFRACTION is a power of two, mcount can use shifting - instead of integer division. Precompute shift amount. */ - log_hashfraction = ffs (hashfraction * sizeof (*froms)) - 1; - else - log_hashfraction = -1; - tossize = textsize / HASHFRACTION; - fromlimit = textsize * ARCDENSITY / 100; - if (fromlimit < MINARCS) - fromlimit = MINARCS; - if (fromlimit > MAXARCS) - fromlimit = MAXARCS; - fromssize = fromlimit * sizeof (struct here_fromstruct); - - expected_size = (sizeof (struct gmon_hdr) - + 4 + sizeof (struct gmon_hist_hdr) + kcountsize - + 4 + 4 + fromssize * sizeof (struct here_cg_arc_record)); - - /* Create the gmon_hdr we expect or write. */ - memset (&gmon_hdr, '\0', sizeof (struct gmon_hdr)); - memcpy (&gmon_hdr.cookie[0], GMON_MAGIC, sizeof (gmon_hdr.cookie)); - *(int32_t *) gmon_hdr.version = GMON_SHOBJ_VERSION; - - /* Create the hist_hdr we expect or write. */ - *(char **) hist_hdr.low_pc = (char *) mapstart; - *(char **) hist_hdr.high_pc = (char *) mapend; - *(int32_t *) hist_hdr.hist_size = kcountsize / sizeof (HISTCOUNTER); - *(int32_t *) hist_hdr.prof_rate = __profile_frequency (); - strncpy (hist_hdr.dimen, "seconds", sizeof (hist_hdr.dimen)); - hist_hdr.dimen_abbrev = 's'; - - /* First determine the output name. We write in the directory - OUTPUT_DIR and the name is composed from the shared objects - soname (or the file name) and the ending ".profile". */ - filename = (char *) alloca (strlen (output_dir) + 1 + strlen (_dl_profile) - + sizeof ".profile"); - cp = strcpy (filename, output_dir); - cp += strlen (output_dir); - *cp++ = '/'; - tmp = strcpy (cp, _dl_profile); - tmp += strlen (_dl_profile); - strcpy (tmp, ".profile"); - -#ifdef O_NOFOLLOW -# define EXTRA_FLAGS | O_NOFOLLOW -#else -# define EXTRA_FLAGS -#endif - fd = __open (filename, O_RDWR | O_CREAT EXTRA_FLAGS); - if (fd == -1) - { - /* We cannot write the profiling data so don't do anything. */ - char buf[400]; - _dl_error_printf ("%s: cannot open file: %s\n", filename, - __strerror_r (errno, buf, sizeof buf)); - return; - } - - if (fstat64 (fd, &st) < 0 || !S_ISREG (st.st_mode)) - { - /* Not stat'able or not a regular file => don't use it. */ - char buf[400]; - int errnum = errno; - __close (fd); - _dl_error_printf ("%s: cannot stat file: %s\n", filename, - __strerror_r (errnum, buf, sizeof buf)); - return; - } - - /* Test the size. If it does not match what we expect from the size - values in the map MAP we don't use it and warn the user. */ - if (st.st_size == 0) - { - /* We have to create the file. */ - char buf[_dl_pagesize]; - - memset (buf, '\0', _dl_pagesize); - - if (__lseek (fd, expected_size & ~(_dl_pagesize - 1), SEEK_SET) == -1) - { - char buf[400]; - int errnum; - cannot_create: - errnum = errno; - __close (fd); - _dl_error_printf ("%s: cannot create file: %s\n", filename, - __strerror_r (errnum, buf, sizeof buf)); - return; - } - - if (TEMP_FAILURE_RETRY (__libc_write (fd, buf, (expected_size - & (_dl_pagesize - 1)))) - < 0) - goto cannot_create; - } - else if (st.st_size != expected_size) - { - __close (fd); - wrong_format: - - if (addr != NULL) - __munmap ((void *) addr, expected_size); - - _dl_error_printf ("%s: file is no correct profile data file for `%s'\n", - filename, _dl_profile); - return; - } - - addr = (struct gmon_hdr *) __mmap (NULL, expected_size, PROT_READ|PROT_WRITE, - MAP_SHARED|MAP_FILE, fd, 0); - if (addr == (struct gmon_hdr *) MAP_FAILED) - { - char buf[400]; - int errnum = errno; - __close (fd); - _dl_error_printf ("%s: cannot map file: %s\n", filename, - __strerror_r (errnum, buf, sizeof buf)); - return; - } - - /* We don't need the file desriptor anymore. */ - __close (fd); - - /* Pointer to data after the header. */ - hist = (char *) (addr + 1); - kcount = (uint16_t *) ((char *) hist + sizeof (uint32_t) - + sizeof (struct gmon_hist_hdr)); - - /* Compute pointer to array of the arc information. */ - narcsp = (uint32_t *) ((char *) kcount + kcountsize + sizeof (uint32_t)); - data = (struct here_cg_arc_record *) ((char *) narcsp + sizeof (uint32_t)); - - if (st.st_size == 0) - { - /* Create the signature. */ - memcpy (addr, &gmon_hdr, sizeof (struct gmon_hdr)); - - *(uint32_t *) hist = GMON_TAG_TIME_HIST; - memcpy (hist + sizeof (uint32_t), &hist_hdr, - sizeof (struct gmon_hist_hdr)); - - narcsp[-1] = GMON_TAG_CG_ARC; - } - else - { - /* Test the signature in the file. */ - if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0 - || *(uint32_t *) hist != GMON_TAG_TIME_HIST - || memcmp (hist + sizeof (uint32_t), &hist_hdr, - sizeof (struct gmon_hist_hdr)) != 0 - || narcsp[-1] != GMON_TAG_CG_ARC) - goto wrong_format; - } - - /* Allocate memory for the froms data and the pointer to the tos records. */ - tos = (uint16_t *) calloc (tossize + fromssize, 1); - if (tos == NULL) - { - __munmap ((void *) addr, expected_size); - _dl_fatal_printf ("Out of memory while initializing profiler\n"); - /* NOTREACHED */ - } - - froms = (struct here_fromstruct *) ((char *) tos + tossize); - fromidx = 0; - - /* Now we have to process all the arc count entries. BTW: it is - not critical whether the *NARCSP value changes meanwhile. Before - we enter a new entry in to toset we will check that everything is - available in TOS. This happens in _dl_mcount. - - Loading the entries in reverse order should help to get the most - frequently used entries at the front of the list. */ - for (idx = narcs = MIN (*narcsp, fromlimit); idx > 0; ) - { - size_t to_index; - size_t newfromidx; - --idx; - to_index = (data[idx].self_pc / (hashfraction * sizeof (*tos))); - newfromidx = fromidx++; - froms[newfromidx].here = &data[idx]; - froms[newfromidx].link = tos[to_index]; - tos[to_index] = newfromidx; - } - - /* Setup counting data. */ - if (kcountsize < highpc - lowpc) - { -#if 0 - s_scale = ((double) kcountsize / (highpc - lowpc)) * SCALE_1_TO_1; -#else - size_t range = highpc - lowpc; - size_t quot = range / kcountsize; - - if (quot >= SCALE_1_TO_1) - s_scale = 1; - else if (quot >= SCALE_1_TO_1 / 256) - s_scale = SCALE_1_TO_1 / quot; - else if (range > ULONG_MAX / 256) - s_scale = (SCALE_1_TO_1 * 256) / (range / (kcountsize / 256)); - else - s_scale = (SCALE_1_TO_1 * 256) / ((range * 256) / kcountsize); -#endif - } - else - s_scale = SCALE_1_TO_1; - - /* Start the profiler. */ - profil ((void *) kcount, kcountsize, lowpc, s_scale); - - /* Turn on profiling. */ - running = 1; -} - - -void -_dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc) -{ - volatile uint16_t *topcindex; - size_t i, fromindex; - struct here_fromstruct *fromp; - - if (! running) - return; - - /* Compute relative addresses. The shared object can be loaded at - any address. The value of frompc could be anything. We cannot - restrict it in any way, just set to a fixed value (0) in case it - is outside the allowed range. These calls show up as calls from - <external> in the gprof output. */ - frompc -= lowpc; - if (frompc >= textsize) - frompc = 0; - selfpc -= lowpc; - if (selfpc >= textsize) - goto done; - - /* Getting here we now have to find out whether the location was - already used. If yes we are lucky and only have to increment a - counter (this also has to be atomic). If the entry is new things - are getting complicated... */ - - /* Avoid integer divide if possible. */ - if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) - i = selfpc >> log_hashfraction; - else - i = selfpc / (hashfraction * sizeof (*tos)); - - topcindex = &tos[i]; - fromindex = *topcindex; - - if (fromindex == 0) - goto check_new_or_add; - - fromp = &froms[fromindex]; - - /* We have to look through the chain of arcs whether there is already - an entry for our arc. */ - while (fromp->here->from_pc != frompc) - { - if (fromp->link != 0) - do - fromp = &froms[fromp->link]; - while (fromp->link != 0 && fromp->here->from_pc != frompc); - - if (fromp->here->from_pc != frompc) - { - topcindex = &fromp->link; - - check_new_or_add: - /* Our entry is not among the entries we read so far from the - data file. Now see whether we have to update the list. */ - while (narcs != *narcsp && narcs < fromlimit) - { - size_t to_index; - size_t newfromidx; - to_index = (data[narcs].self_pc - / (hashfraction * sizeof (*tos))); - newfromidx = exchange_and_add (&fromidx, 1) + 1; - froms[newfromidx].here = &data[narcs]; - froms[newfromidx].link = tos[to_index]; - tos[to_index] = newfromidx; - atomic_add (&narcs, 1); - } - - /* If we still have no entry stop searching and insert. */ - if (*topcindex == 0) - { - uint32_t newarc = exchange_and_add (narcsp, 1); - - /* In rare cases it could happen that all entries in FROMS are - occupied. So we cannot count this anymore. */ - if (newarc >= fromlimit) - goto done; - - *topcindex = exchange_and_add (&fromidx, 1) + 1; - fromp = &froms[*topcindex]; - - fromp->here = &data[newarc]; - data[newarc].from_pc = frompc; - data[newarc].self_pc = selfpc; - data[newarc].count = 0; - fromp->link = 0; - atomic_add (&narcs, 1); - - break; - } - - fromp = &froms[*topcindex]; - } - else - /* Found in. */ - break; - } - - /* Increment the counter. */ - atomic_add (&fromp->here->count, 1); - - done: - ; -} |