X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Flinux-tdep.c;h=ff3ada78c6b98e550e1c10c96e4d9be0867fa265;hb=791bb1f4a6310cd7f894e370607dfc05c9cb0727;hp=7a766707994872595a410c7ff6022adc89b4990b;hpb=f968fe80b09ddc88538db2250b367fc0074739fa;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c index 7a76670799..ff3ada78c6 100644 --- a/gdb/linux-tdep.c +++ b/gdb/linux-tdep.c @@ -1,6 +1,6 @@ /* Target-dependent code for GNU/Linux, architecture independent. - Copyright (C) 2009-2014 Free Software Foundation, Inc. + Copyright (C) 2009-2015 Free Software Foundation, Inc. This file is part of GDB. @@ -32,9 +32,64 @@ #include "cli/cli-utils.h" #include "arch-utils.h" #include "gdb_obstack.h" +#include "observer.h" +#include "objfiles.h" +#include "infcall.h" +#include "gdbcmd.h" +#include "gdb_regex.h" #include +/* This enum represents the values that the user can choose when + informing the Linux kernel about which memory mappings will be + dumped in a corefile. They are described in the file + Documentation/filesystems/proc.txt, inside the Linux kernel + tree. */ + +enum filterflags + { + COREFILTER_ANON_PRIVATE = 1 << 0, + COREFILTER_ANON_SHARED = 1 << 1, + COREFILTER_MAPPED_PRIVATE = 1 << 2, + COREFILTER_MAPPED_SHARED = 1 << 3, + COREFILTER_ELF_HEADERS = 1 << 4, + COREFILTER_HUGETLB_PRIVATE = 1 << 5, + COREFILTER_HUGETLB_SHARED = 1 << 6, + }; + +/* This struct is used to map flags found in the "VmFlags:" field (in + the /proc//smaps file). */ + +struct smaps_vmflags + { + /* Zero if this structure has not been initialized yet. It + probably means that the Linux kernel being used does not emit + the "VmFlags:" field on "/proc/PID/smaps". */ + + unsigned int initialized_p : 1; + + /* Memory mapped I/O area (VM_IO, "io"). */ + + unsigned int io_page : 1; + + /* Area uses huge TLB pages (VM_HUGETLB, "ht"). */ + + unsigned int uses_huge_tlb : 1; + + /* Do not include this memory region on the coredump (VM_DONTDUMP, "dd"). */ + + unsigned int exclude_coredump : 1; + + /* Is this a MAP_SHARED mapping (VM_SHARED, "sh"). */ + + unsigned int shared_mapping : 1; + }; + +/* Whether to take the /proc/PID/coredump_filter into account when + generating a corefile. */ + +static int use_coredump_filter = 1; + /* This enum represents the signals' numbers on a generic architecture running the Linux kernel. The definition of "generic" comes from the file , from the Linux kernel @@ -119,10 +174,76 @@ get_linux_gdbarch_data (struct gdbarch *gdbarch) return gdbarch_data (gdbarch, linux_gdbarch_data_handle); } +/* Per-inferior data key. */ +static const struct inferior_data *linux_inferior_data; + +/* Linux-specific cached data. This is used by GDB for caching + purposes for each inferior. This helps reduce the overhead of + transfering data from a remote target to the local host. */ +struct linux_info +{ + /* Cache of the inferior's vsyscall/vDSO mapping range. Only valid + if VSYSCALL_RANGE_P is positive. This is cached because getting + at this info requires an auxv lookup (which is itself cached), + and looking through the inferior's mappings (which change + throughout execution and therefore cannot be cached). */ + struct mem_range vsyscall_range; + + /* Zero if we haven't tried looking up the vsyscall's range before + yet. Positive if we tried looking it up, and found it. Negative + if we tried looking it up but failed. */ + int vsyscall_range_p; +}; + +/* Frees whatever allocated space there is to be freed and sets INF's + linux cache data pointer to NULL. */ + +static void +invalidate_linux_cache_inf (struct inferior *inf) +{ + struct linux_info *info; + + info = inferior_data (inf, linux_inferior_data); + if (info != NULL) + { + xfree (info); + set_inferior_data (inf, linux_inferior_data, NULL); + } +} + +/* Handles the cleanup of the linux cache for inferior INF. ARG is + ignored. Callback for the inferior_appeared and inferior_exit + events. */ + +static void +linux_inferior_data_cleanup (struct inferior *inf, void *arg) +{ + invalidate_linux_cache_inf (inf); +} + +/* Fetch the linux cache info for INF. This function always returns a + valid INFO pointer. */ + +static struct linux_info * +get_linux_inferior_data (void) +{ + struct linux_info *info; + struct inferior *inf = current_inferior (); + + info = inferior_data (inf, linux_inferior_data); + if (info == NULL) + { + info = XCNEW (struct linux_info); + set_inferior_data (inf, linux_inferior_data, info); + } + + return info; +} + /* This function is suitable for architectures that don't extend/override the standard siginfo structure. */ -struct type * +static struct type * linux_get_siginfo_type (struct gdbarch *gdbarch) { struct linux_gdbarch_data *linux_gdbarch_data; @@ -312,6 +433,248 @@ read_mapping (const char *line, *filename = p; } +/* Helper function to decode the "VmFlags" field in /proc/PID/smaps. + + This function was based on the documentation found on + , on the Linux kernel. + + Linux kernels before commit + 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have this + field on smaps. */ + +static void +decode_vmflags (char *p, struct smaps_vmflags *v) +{ + char *saveptr = NULL; + const char *s; + + v->initialized_p = 1; + p = skip_to_space (p); + p = skip_spaces (p); + + for (s = strtok_r (p, " ", &saveptr); + s != NULL; + s = strtok_r (NULL, " ", &saveptr)) + { + if (strcmp (s, "io") == 0) + v->io_page = 1; + else if (strcmp (s, "ht") == 0) + v->uses_huge_tlb = 1; + else if (strcmp (s, "dd") == 0) + v->exclude_coredump = 1; + else if (strcmp (s, "sh") == 0) + v->shared_mapping = 1; + } +} + +/* Return 1 if the memory mapping is anonymous, 0 otherwise. + + FILENAME is the name of the file present in the first line of the + memory mapping, in the "/proc/PID/smaps" output. For example, if + the first line is: + + 7fd0ca877000-7fd0d0da0000 r--p 00000000 fd:02 2100770 /path/to/file + + Then FILENAME will be "/path/to/file". */ + +static int +mapping_is_anonymous_p (const char *filename) +{ + static regex_t dev_zero_regex, shmem_file_regex, file_deleted_regex; + static int init_regex_p = 0; + + if (!init_regex_p) + { + struct cleanup *c = make_cleanup (null_cleanup, NULL); + + /* Let's be pessimistic and assume there will be an error while + compiling the regex'es. */ + init_regex_p = -1; + + /* DEV_ZERO_REGEX matches "/dev/zero" filenames (with or + without the "(deleted)" string in the end). We know for + sure, based on the Linux kernel code, that memory mappings + whose associated filename is "/dev/zero" are guaranteed to be + MAP_ANONYMOUS. */ + compile_rx_or_error (&dev_zero_regex, "^/dev/zero\\( (deleted)\\)\\?$", + _("Could not compile regex to match /dev/zero " + "filename")); + /* SHMEM_FILE_REGEX matches "/SYSV%08x" filenames (with or + without the "(deleted)" string in the end). These filenames + refer to shared memory (shmem), and memory mappings + associated with them are MAP_ANONYMOUS as well. */ + compile_rx_or_error (&shmem_file_regex, + "^/\\?SYSV[0-9a-fA-F]\\{8\\}\\( (deleted)\\)\\?$", + _("Could not compile regex to match shmem " + "filenames")); + /* FILE_DELETED_REGEX is a heuristic we use to try to mimic the + Linux kernel's 'n_link == 0' code, which is responsible to + decide if it is dealing with a 'MAP_SHARED | MAP_ANONYMOUS' + mapping. In other words, if FILE_DELETED_REGEX matches, it + does not necessarily mean that we are dealing with an + anonymous shared mapping. However, there is no easy way to + detect this currently, so this is the best approximation we + have. + + As a result, GDB will dump readonly pages of deleted + executables when using the default value of coredump_filter + (0x33), while the Linux kernel will not dump those pages. + But we can live with that. */ + compile_rx_or_error (&file_deleted_regex, " (deleted)$", + _("Could not compile regex to match " + "' (deleted)'")); + /* We will never release these regexes, so just discard the + cleanups. */ + discard_cleanups (c); + + /* If we reached this point, then everything succeeded. */ + init_regex_p = 1; + } + + if (init_regex_p == -1) + { + const char deleted[] = " (deleted)"; + size_t del_len = sizeof (deleted) - 1; + size_t filename_len = strlen (filename); + + /* There was an error while compiling the regex'es above. In + order to try to give some reliable information to the caller, + we just try to find the string " (deleted)" in the filename. + If we managed to find it, then we assume the mapping is + anonymous. */ + return (filename_len >= del_len + && strcmp (filename + filename_len - del_len, deleted) == 0); + } + + if (*filename == '\0' + || regexec (&dev_zero_regex, filename, 0, NULL, 0) == 0 + || regexec (&shmem_file_regex, filename, 0, NULL, 0) == 0 + || regexec (&file_deleted_regex, filename, 0, NULL, 0) == 0) + return 1; + + return 0; +} + +/* Return 0 if the memory mapping (which is related to FILTERFLAGS, V, + MAYBE_PRIVATE_P, and MAPPING_ANONYMOUS_P) should not be dumped, or + greater than 0 if it should. + + In a nutshell, this is the logic that we follow in order to decide + if a mapping should be dumped or not. + + - If the mapping is associated to a file whose name ends with + " (deleted)", or if the file is "/dev/zero", or if it is + "/SYSV%08x" (shared memory), or if there is no file associated + with it, or if the AnonHugePages: or the Anonymous: fields in the + /proc/PID/smaps have contents, then GDB considers this mapping to + be anonymous. Otherwise, GDB considers this mapping to be a + file-backed mapping (because there will be a file associated with + it). + + It is worth mentioning that, from all those checks described + above, the most fragile is the one to see if the file name ends + with " (deleted)". This does not necessarily mean that the + mapping is anonymous, because the deleted file associated with + the mapping may have been a hard link to another file, for + example. The Linux kernel checks to see if "i_nlink == 0", but + GDB cannot easily (and normally) do this check (iff running as + root, it could find the mapping in /proc/PID/map_files/ and + determine whether there still are other hard links to the + inode/file). Therefore, we made a compromise here, and we assume + that if the file name ends with " (deleted)", then the mapping is + indeed anonymous. FWIW, this is something the Linux kernel could + do better: expose this information in a more direct way. + + - If we see the flag "sh" in the "VmFlags:" field (in + /proc/PID/smaps), then certainly the memory mapping is shared + (VM_SHARED). If we have access to the VmFlags, and we don't see + the "sh" there, then certainly the mapping is private. However, + Linux kernels before commit + 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have the + "VmFlags:" field; in that case, we use another heuristic: if we + see 'p' in the permission flags, then we assume that the mapping + is private, even though the presence of the 's' flag there would + mean VM_MAYSHARE, which means the mapping could still be private. + This should work OK enough, however. */ + +static int +dump_mapping_p (enum filterflags filterflags, const struct smaps_vmflags *v, + int maybe_private_p, int mapping_anon_p, int mapping_file_p, + const char *filename) +{ + /* Initially, we trust in what we received from our caller. This + value may not be very precise (i.e., it was probably gathered + from the permission line in the /proc/PID/smaps list, which + actually refers to VM_MAYSHARE, and not VM_SHARED), but it is + what we have until we take a look at the "VmFlags:" field + (assuming that the version of the Linux kernel being used + supports it, of course). */ + int private_p = maybe_private_p; + + /* We always dump vDSO and vsyscall mappings, because it's likely that + there'll be no file to read the contents from at core load time. + The kernel does the same. */ + if (strcmp ("[vdso]", filename) == 0 + || strcmp ("[vsyscall]", filename) == 0) + return 1; + + if (v->initialized_p) + { + /* We never dump I/O mappings. */ + if (v->io_page) + return 0; + + /* Check if we should exclude this mapping. */ + if (v->exclude_coredump) + return 0; + + /* Update our notion of whether this mapping is shared or + private based on a trustworthy value. */ + private_p = !v->shared_mapping; + + /* HugeTLB checking. */ + if (v->uses_huge_tlb) + { + if ((private_p && (filterflags & COREFILTER_HUGETLB_PRIVATE)) + || (!private_p && (filterflags & COREFILTER_HUGETLB_SHARED))) + return 1; + + return 0; + } + } + + if (private_p) + { + if (mapping_anon_p && mapping_file_p) + { + /* This is a special situation. It can happen when we see a + mapping that is file-backed, but that contains anonymous + pages. */ + return ((filterflags & COREFILTER_ANON_PRIVATE) != 0 + || (filterflags & COREFILTER_MAPPED_PRIVATE) != 0); + } + else if (mapping_anon_p) + return (filterflags & COREFILTER_ANON_PRIVATE) != 0; + else + return (filterflags & COREFILTER_MAPPED_PRIVATE) != 0; + } + else + { + if (mapping_anon_p && mapping_file_p) + { + /* This is a special situation. It can happen when we see a + mapping that is file-backed, but that contains anonymous + pages. */ + return ((filterflags & COREFILTER_ANON_SHARED) != 0 + || (filterflags & COREFILTER_MAPPED_SHARED) != 0); + } + else if (mapping_anon_p) + return (filterflags & COREFILTER_ANON_SHARED) != 0; + else + return (filterflags & COREFILTER_MAPPED_SHARED) != 0; + } +} + /* Implement the "info proc" command. */ static void @@ -356,7 +719,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (cmdline_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/cmdline", pid); - data = target_fileio_read_stralloc (filename); + data = target_fileio_read_stralloc (NULL, filename); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -369,7 +732,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (cwd_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/cwd", pid); - data = target_fileio_readlink (filename, &target_errno); + data = target_fileio_readlink (NULL, filename, &target_errno); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -382,7 +745,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (exe_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/exe", pid); - data = target_fileio_readlink (filename, &target_errno); + data = target_fileio_readlink (NULL, filename, &target_errno); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -395,7 +758,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (mappings_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/maps", pid); - data = target_fileio_read_stralloc (filename); + data = target_fileio_read_stralloc (NULL, filename); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -456,7 +819,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (status_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/status", pid); - data = target_fileio_read_stralloc (filename); + data = target_fileio_read_stralloc (NULL, filename); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -469,7 +832,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args, if (stat_f) { xsnprintf (filename, sizeof filename, "/proc/%ld/stat", pid); - data = target_fileio_read_stralloc (filename); + data = target_fileio_read_stralloc (NULL, filename); if (data) { struct cleanup *cleanup = make_cleanup (xfree, data); @@ -750,48 +1113,98 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch, void *obfd) { char mapsfilename[100]; - char *data; + char coredumpfilter_name[100]; + char *data, *coredumpfilterdata; + pid_t pid; + /* Default dump behavior of coredump_filter (0x33), according to + Documentation/filesystems/proc.txt from the Linux kernel + tree. */ + enum filterflags filterflags = (COREFILTER_ANON_PRIVATE + | COREFILTER_ANON_SHARED + | COREFILTER_ELF_HEADERS + | COREFILTER_HUGETLB_PRIVATE); /* We need to know the real target PID to access /proc. */ if (current_inferior ()->fake_pid_p) return 1; - xsnprintf (mapsfilename, sizeof mapsfilename, - "/proc/%d/smaps", current_inferior ()->pid); - data = target_fileio_read_stralloc (mapsfilename); + pid = current_inferior ()->pid; + + if (use_coredump_filter) + { + xsnprintf (coredumpfilter_name, sizeof (coredumpfilter_name), + "/proc/%d/coredump_filter", pid); + coredumpfilterdata = target_fileio_read_stralloc (NULL, + coredumpfilter_name); + if (coredumpfilterdata != NULL) + { + sscanf (coredumpfilterdata, "%x", &filterflags); + xfree (coredumpfilterdata); + } + } + + xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/smaps", pid); + data = target_fileio_read_stralloc (NULL, mapsfilename); if (data == NULL) { /* Older Linux kernels did not support /proc/PID/smaps. */ - xsnprintf (mapsfilename, sizeof mapsfilename, - "/proc/%d/maps", current_inferior ()->pid); - data = target_fileio_read_stralloc (mapsfilename); + xsnprintf (mapsfilename, sizeof mapsfilename, "/proc/%d/maps", pid); + data = target_fileio_read_stralloc (NULL, mapsfilename); } - if (data) + + if (data != NULL) { struct cleanup *cleanup = make_cleanup (xfree, data); - char *line; + char *line, *t; - line = strtok (data, "\n"); - while (line) + line = strtok_r (data, "\n", &t); + while (line != NULL) { ULONGEST addr, endaddr, offset, inode; const char *permissions, *device, *filename; + struct smaps_vmflags v; size_t permissions_len, device_len; - int read, write, exec; - int modified = 0, has_anonymous = 0; + int read, write, exec, priv; + int has_anonymous = 0; + int should_dump_p = 0; + int mapping_anon_p; + int mapping_file_p; + memset (&v, 0, sizeof (v)); read_mapping (line, &addr, &endaddr, &permissions, &permissions_len, &offset, &device, &device_len, &inode, &filename); + mapping_anon_p = mapping_is_anonymous_p (filename); + /* If the mapping is not anonymous, then we can consider it + to be file-backed. These two states (anonymous or + file-backed) seem to be exclusive, but they can actually + coexist. For example, if a file-backed mapping has + "Anonymous:" pages (see more below), then the Linux + kernel will dump this mapping when the user specified + that she only wants anonymous mappings in the corefile + (*even* when she explicitly disabled the dumping of + file-backed mappings). */ + mapping_file_p = !mapping_anon_p; /* Decode permissions. */ read = (memchr (permissions, 'r', permissions_len) != 0); write = (memchr (permissions, 'w', permissions_len) != 0); exec = (memchr (permissions, 'x', permissions_len) != 0); - - /* Try to detect if region was modified by parsing smaps counters. */ - for (line = strtok (NULL, "\n"); - line && line[0] >= 'A' && line[0] <= 'Z'; - line = strtok (NULL, "\n")) + /* 'private' here actually means VM_MAYSHARE, and not + VM_SHARED. In order to know if a mapping is really + private or not, we must check the flag "sh" in the + VmFlags field. This is done by decode_vmflags. However, + if we are using a Linux kernel released before the commit + 834f82e2aa9a8ede94b17b656329f850c1471514 (3.10), we will + not have the VmFlags there. In this case, there is + really no way to know if we are dealing with VM_SHARED, + so we just assume that VM_MAYSHARE is enough. */ + priv = memchr (permissions, 'p', permissions_len) != 0; + + /* Try to detect if region should be dumped by parsing smaps + counters. */ + for (line = strtok_r (NULL, "\n", &t); + line != NULL && line[0] >= 'A' && line[0] <= 'Z'; + line = strtok_r (NULL, "\n", &t)) { char keyword[64 + 1]; @@ -800,11 +1213,17 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch, warning (_("Error parsing {s,}maps file '%s'"), mapsfilename); break; } + if (strcmp (keyword, "Anonymous:") == 0) - has_anonymous = 1; - if (strcmp (keyword, "Shared_Dirty:") == 0 - || strcmp (keyword, "Private_Dirty:") == 0 - || strcmp (keyword, "Swap:") == 0 + { + /* Older Linux kernels did not support the + "Anonymous:" counter. Check it here. */ + has_anonymous = 1; + } + else if (strcmp (keyword, "VmFlags:") == 0) + decode_vmflags (line, &v); + + if (strcmp (keyword, "AnonHugePages:") == 0 || strcmp (keyword, "Anonymous:") == 0) { unsigned long number; @@ -815,19 +1234,46 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch, mapsfilename); break; } - if (number != 0) - modified = 1; + if (number > 0) + { + /* Even if we are dealing with a file-backed + mapping, if it contains anonymous pages we + consider it to be *also* an anonymous + mapping, because this is what the Linux + kernel does: + + // Dump segments that have been written to. + if (vma->anon_vma && FILTER(ANON_PRIVATE)) + goto whole; + + Note that if the mapping is already marked as + file-backed (i.e., mapping_file_p is + non-zero), then this is a special case, and + this mapping will be dumped either when the + user wants to dump file-backed *or* anonymous + mappings. */ + mapping_anon_p = 1; + } } } - /* Older Linux kernels did not support the "Anonymous:" counter. - If it is missing, we can't be sure - dump all the pages. */ - if (!has_anonymous) - modified = 1; + if (has_anonymous) + should_dump_p = dump_mapping_p (filterflags, &v, priv, + mapping_anon_p, mapping_file_p, + filename); + else + { + /* Older Linux kernels did not support the "Anonymous:" counter. + If it is missing, we can't be sure - dump all the pages. */ + should_dump_p = 1; + } /* Invoke the callback function to create the corefile segment. */ - func (addr, endaddr - addr, offset, inode, - read, write, exec, modified, filename, obfd); + if (should_dump_p) + func (addr, endaddr - addr, offset, inode, + read, write, exec, 1, /* MODIFIED is true because we + want to dump the mapping. */ + filename, obfd); } do_cleanups (cleanup); @@ -1310,7 +1756,7 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p) /* Obtaining PID and filename. */ pid = ptid_get_pid (inferior_ptid); xsnprintf (filename, sizeof (filename), "/proc/%d/cmdline", (int) pid); - fname = target_fileio_read_stralloc (filename); + fname = target_fileio_read_stralloc (NULL, filename); if (fname == NULL || *fname == '\0') { @@ -1343,7 +1789,7 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p) p->pr_psargs[sizeof (p->pr_psargs) - 1] = '\0'; xsnprintf (filename, sizeof (filename), "/proc/%d/stat", (int) pid); - proc_stat = target_fileio_read_stralloc (filename); + proc_stat = target_fileio_read_stralloc (NULL, filename); make_cleanup (xfree, proc_stat); if (proc_stat == NULL || *proc_stat == '\0') @@ -1424,7 +1870,7 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p) /* Finally, obtaining the UID and GID. For that, we read and parse the contents of the `/proc/PID/status' file. */ xsnprintf (filename, sizeof (filename), "/proc/%d/status", (int) pid); - proc_status = target_fileio_read_stralloc (filename); + proc_status = target_fileio_read_stralloc (NULL, filename); make_cleanup (xfree, proc_status); if (proc_status == NULL || *proc_status == '\0') @@ -1476,7 +1922,6 @@ linux_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd, int *note_size) char *note_data = NULL; gdb_byte *auxv; int auxv_len; - volatile struct gdb_exception e; if (! gdbarch_iterate_over_regset_sections_p (gdbarch)) return NULL; @@ -1503,12 +1948,16 @@ linux_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd, int *note_size) } /* Thread register information. */ - TRY_CATCH (e, RETURN_MASK_ERROR) + TRY { update_thread_list (); } - if (e.reason < 0) - exception_print (gdb_stderr, e); + CATCH (e, RETURN_MASK_ERROR) + { + exception_print (gdb_stderr, e); + } + END_CATCH + thread_args.gdbarch = gdbarch; thread_args.pid = ptid_get_pid (inferior_ptid); thread_args.obfd = obfd; @@ -1796,6 +2245,181 @@ linux_gdb_signal_to_target (struct gdbarch *gdbarch, return -1; } +/* Rummage through mappings to find a mapping's size. */ + +static int +find_mapping_size (CORE_ADDR vaddr, unsigned long size, + int read, int write, int exec, int modified, + void *data) +{ + struct mem_range *range = data; + + if (vaddr == range->start) + { + range->length = size; + return 1; + } + return 0; +} + +/* Helper for linux_vsyscall_range that does the real work of finding + the vsyscall's address range. */ + +static int +linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range) +{ + if (target_auxv_search (¤t_target, AT_SYSINFO_EHDR, &range->start) <= 0) + return 0; + + /* This is installed by linux_init_abi below, so should always be + available. */ + gdb_assert (gdbarch_find_memory_regions_p (target_gdbarch ())); + + range->length = 0; + gdbarch_find_memory_regions (gdbarch, find_mapping_size, range); + return 1; +} + +/* Implementation of the "vsyscall_range" gdbarch hook. Handles + caching, and defers the real work to linux_vsyscall_range_raw. */ + +static int +linux_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range) +{ + struct linux_info *info = get_linux_inferior_data (); + + if (info->vsyscall_range_p == 0) + { + if (linux_vsyscall_range_raw (gdbarch, &info->vsyscall_range)) + info->vsyscall_range_p = 1; + else + info->vsyscall_range_p = -1; + } + + if (info->vsyscall_range_p < 0) + return 0; + + *range = info->vsyscall_range; + return 1; +} + +/* Symbols for linux_infcall_mmap's ARG_FLAGS; their Linux MAP_* system + definitions would be dependent on compilation host. */ +#define GDB_MMAP_MAP_PRIVATE 0x02 /* Changes are private. */ +#define GDB_MMAP_MAP_ANONYMOUS 0x20 /* Don't use a file. */ + +/* See gdbarch.sh 'infcall_mmap'. */ + +static CORE_ADDR +linux_infcall_mmap (CORE_ADDR size, unsigned prot) +{ + struct objfile *objf; + /* Do there still exist any Linux systems without "mmap64"? + "mmap" uses 64-bit off_t on x86_64 and 32-bit off_t on i386 and x32. */ + struct value *mmap_val = find_function_in_inferior ("mmap64", &objf); + struct value *addr_val; + struct gdbarch *gdbarch = get_objfile_arch (objf); + CORE_ADDR retval; + enum + { + ARG_ADDR, ARG_LENGTH, ARG_PROT, ARG_FLAGS, ARG_FD, ARG_OFFSET, ARG_LAST + }; + struct value *arg[ARG_LAST]; + + arg[ARG_ADDR] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, + 0); + /* Assuming sizeof (unsigned long) == sizeof (size_t). */ + arg[ARG_LENGTH] = value_from_ulongest + (builtin_type (gdbarch)->builtin_unsigned_long, size); + gdb_assert ((prot & ~(GDB_MMAP_PROT_READ | GDB_MMAP_PROT_WRITE + | GDB_MMAP_PROT_EXEC)) + == 0); + arg[ARG_PROT] = value_from_longest (builtin_type (gdbarch)->builtin_int, prot); + arg[ARG_FLAGS] = value_from_longest (builtin_type (gdbarch)->builtin_int, + GDB_MMAP_MAP_PRIVATE + | GDB_MMAP_MAP_ANONYMOUS); + arg[ARG_FD] = value_from_longest (builtin_type (gdbarch)->builtin_int, -1); + arg[ARG_OFFSET] = value_from_longest (builtin_type (gdbarch)->builtin_int64, + 0); + addr_val = call_function_by_hand (mmap_val, ARG_LAST, arg); + retval = value_as_address (addr_val); + if (retval == (CORE_ADDR) -1) + error (_("Failed inferior mmap call for %s bytes, errno is changed."), + pulongest (size)); + return retval; +} + +/* See gdbarch.sh 'infcall_munmap'. */ + +static void +linux_infcall_munmap (CORE_ADDR addr, CORE_ADDR size) +{ + struct objfile *objf; + struct value *munmap_val = find_function_in_inferior ("munmap", &objf); + struct value *retval_val; + struct gdbarch *gdbarch = get_objfile_arch (objf); + LONGEST retval; + enum + { + ARG_ADDR, ARG_LENGTH, ARG_LAST + }; + struct value *arg[ARG_LAST]; + + arg[ARG_ADDR] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, + addr); + /* Assuming sizeof (unsigned long) == sizeof (size_t). */ + arg[ARG_LENGTH] = value_from_ulongest + (builtin_type (gdbarch)->builtin_unsigned_long, size); + retval_val = call_function_by_hand (munmap_val, ARG_LAST, arg); + retval = value_as_long (retval_val); + if (retval != 0) + warning (_("Failed inferior munmap call at %s for %s bytes, " + "errno is changed."), + hex_string (addr), pulongest (size)); +} + +/* See linux-tdep.h. */ + +CORE_ADDR +linux_displaced_step_location (struct gdbarch *gdbarch) +{ + CORE_ADDR addr; + int bp_len; + + /* Determine entry point from target auxiliary vector. This avoids + the need for symbols. Also, when debugging a stand-alone SPU + executable, entry_point_address () will point to an SPU + local-store address and is thus not usable as displaced stepping + location. The auxiliary vector gets us the PowerPC-side entry + point address instead. */ + if (target_auxv_search (¤t_target, AT_ENTRY, &addr) <= 0) + error (_("Cannot find AT_ENTRY auxiliary vector entry.")); + + /* Make certain that the address points at real code, and not a + function descriptor. */ + addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, + ¤t_target); + + /* Inferior calls also use the entry point as a breakpoint location. + We don't want displaced stepping to interfere with those + breakpoints, so leave space. */ + gdbarch_breakpoint_from_pc (gdbarch, &addr, &bp_len); + addr += bp_len * 2; + + return addr; +} + +/* Display whether the gcore command is using the + /proc/PID/coredump_filter file. */ + +static void +show_use_coredump_filter (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("Use of /proc/PID/coredump_filter file to generate" + " corefiles is %s.\n"), value); +} + /* To be called from the various GDB_OSABI_LINUX handlers for the various GNU/Linux architectures and machine types. */ @@ -1813,6 +2437,10 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) linux_gdb_signal_from_target); set_gdbarch_gdb_signal_to_target (gdbarch, linux_gdb_signal_to_target); + set_gdbarch_vsyscall_range (gdbarch, linux_vsyscall_range); + set_gdbarch_infcall_mmap (gdbarch, linux_infcall_mmap); + set_gdbarch_infcall_munmap (gdbarch, linux_infcall_munmap); + set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type); } /* Provide a prototype to silence -Wmissing-prototypes. */ @@ -1823,4 +2451,23 @@ _initialize_linux_tdep (void) { linux_gdbarch_data_handle = gdbarch_data_register_post_init (init_linux_gdbarch_data); + + /* Set a cache per-inferior. */ + linux_inferior_data + = register_inferior_data_with_cleanup (NULL, linux_inferior_data_cleanup); + /* Observers used to invalidate the cache when needed. */ + observer_attach_inferior_exit (invalidate_linux_cache_inf); + observer_attach_inferior_appeared (invalidate_linux_cache_inf); + + add_setshow_boolean_cmd ("use-coredump-filter", class_files, + &use_coredump_filter, _("\ +Set whether gcore should consider /proc/PID/coredump_filter."), + _("\ +Show whether gcore should consider /proc/PID/coredump_filter."), + _("\ +Use this command to set whether gcore should consider the contents\n\ +of /proc/PID/coredump_filter when generating the corefile. For more information\n\ +about this file, refer to the manpage of core(5)."), + NULL, show_use_coredump_filter, + &setlist, &showlist); }