diff options
| -rw-r--r-- | gdb/ChangeLog | 13 | ||||
| -rw-r--r-- | gdb/linux-tdep.c | 102 |
2 files changed, 113 insertions, 2 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 685419a..f64bcc9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2014-10-10 Pedro Alves <palves@redhat.com> + + * linux-tdep.c: Include observer.h. + (linux_inferior_data): New global. + (struct linux_info): New structure. + (invalidate_linux_cache_inf, linux_inferior_data_cleanup) + (get_linux_inferior_data): New functions. + (linux_vsyscall_range): Rename to ... + (linux_vsyscall_range_raw): ... this. + (linux_vsyscall_range): New function; handles caching. + (_initialize_linux_tdep): Register linux_inferior_data. Install + inferior_exit and inferior_appeared observers. + 2014-10-10 Jan Kratochvil <jan.kratochvil@redhat.com> Pedro Alves <palves@redhat.com> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c index 2ffd992..ffc3e87 100644 --- a/gdb/linux-tdep.c +++ b/gdb/linux-tdep.c @@ -32,6 +32,7 @@ #include "cli/cli-utils.h" #include "arch-utils.h" #include "gdb_obstack.h" +#include "observer.h" #include <ctype.h> @@ -119,6 +120,72 @@ 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. */ @@ -1813,10 +1880,11 @@ find_mapping_size (CORE_ADDR vaddr, unsigned long size, return 0; } -/* Implementation of the "vsyscall_range" gdbarch hook. */ +/* Helper for linux_vsyscall_range that does the real work of finding + the vsyscall's address range. */ static int -linux_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range) +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; @@ -1830,6 +1898,29 @@ linux_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *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; +} + /* To be called from the various GDB_OSABI_LINUX handlers for the various GNU/Linux architectures and machine types. */ @@ -1858,4 +1949,11 @@ _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); } |