This patch is to augment Srikar's perf support for uprobes patch (https://lkml.org/lkml/2012/4/11/191) with the following features: a. Instruction verification for user space tracing b. Function boundary validation support to uprobes as its kernel counterpart (Commit-ID: 1c1bc922). This will help in ensuring uprobe is placed at right location inside the intended function. To verify instructions in perf before adding a uprobe, we need to use arch/x86/lib/insn.c. Since perf Makefile enables -Wswitch-default flag it causes build warnings/failures. Masami's patch https://lkml.org/lkml/2012/4/12/598 addresses those warnings and it is a pre-req for this patch. v2 addresses Masami's review comments: Rebuild insn.c and inat.c while building perf and a few other minor ones. Signed-off-by: Prashanth Nageshappa <prashanth@xxxxxxxxxxxxxxxxxx> --- tools/perf/Makefile | 1 tools/perf/arch/x86/Makefile | 20 ++++++++ tools/perf/arch/x86/util/probe-event.c | 84 ++++++++++++++++++++++++++++++++ tools/perf/util/include/linux/string.h | 1 tools/perf/util/probe-event.c | 22 ++++++++ tools/perf/util/probe-event.h | 2 + tools/perf/util/symbol.c | 2 + tools/perf/util/symbol.h | 1 8 files changed, 132 insertions(+), 1 deletions(-) create mode 100644 tools/perf/arch/x86/util/probe-event.c diff --git a/tools/perf/Makefile b/tools/perf/Makefile index 820371f..94879b9 100644 --- a/tools/perf/Makefile +++ b/tools/perf/Makefile @@ -61,6 +61,7 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \ CC = $(CROSS_COMPILE)gcc AR = $(CROSS_COMPILE)ar +AWK = awk # Additional ARCH settings for x86 ifeq ($(ARCH),i386) diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile index 744e629..1a7215b 100644 --- a/tools/perf/arch/x86/Makefile +++ b/tools/perf/arch/x86/Makefile @@ -1,5 +1,25 @@ +inat_tables_script = ../../arch/$(ARCH)/tools/gen-insn-attr-x86.awk +inat_tables_maps = ../../arch/$(ARCH)/lib/x86-opcode-map.txt +cmd_inat_tables = $(AWK) -f $(inat_tables_script) $(inat_tables_maps) > $@ || rm -f $@ + +BASIC_CFLAGS += -I. -I../../arch/$(ARCH)/include + ifndef NO_DWARF PERF_HAVE_DWARF_REGS := 1 LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/probe-event.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/inat.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/insn.o + +$(OUTPUT)arch/$(ARCH)/inat.o:../../arch/$(ARCH)/lib/inat-tables.c + +../../arch/$(ARCH)/lib/inat-tables.c: $(inat_tables_script) $(inat_tables_maps) + $(cmd_inat_tables) + +$(OUTPUT)arch/$(ARCH)/inat.o:../../arch/$(ARCH)/lib/inat.c $(OUTPUT)PERF-CFLAGS + $(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) $< + +$(OUTPUT)arch/$(ARCH)/insn.o:../../arch/$(ARCH)/lib/insn.c $(OUTPUT)PERF-CFLAGS + $(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) $< diff --git a/tools/perf/arch/x86/util/probe-event.c b/tools/perf/arch/x86/util/probe-event.c new file mode 100644 index 0000000..7df9031 --- /dev/null +++ b/tools/perf/arch/x86/util/probe-event.c @@ -0,0 +1,84 @@ +/* + * probe-event.c : x86 specific perf-probe definition + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) IBM Corporation, 2011-2012 + * Authors: + * Prashanth Nageshappa + */ + +#include <util/types.h> +#include <util/probe-event.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <fcntl.h> +#include <string.h> +#include <errno.h> +#include <asm/insn.h> +#include <elf.h> + +/* + * Check if a given offset from start of a function is valid or not + */ +bool can_probe(char *name, unsigned long long vaddr, unsigned long offset, + u8 class) +{ + unsigned long long eaddr, saddr; + unsigned long fileoffset, readbytes; + int fd = 0; + bool ret = false; + char *buf = NULL; + struct insn insn; + + fd = open(name, O_RDONLY); + if (fd == -1) { + pr_warning("Failed to open %s: %s\n", name, strerror(errno)); + return ret; + } + buf = (char *)malloc(offset + MAX_INSN_SIZE); + if (buf == NULL) { + pr_warning("Failed to allocate memory"); + goto out; + } + fileoffset = lseek(fd, vaddr, SEEK_SET); + if (fileoffset != vaddr) { + pr_warning("Failed to lseek %s: %s\n", name, strerror(errno)); + goto out; + } + saddr = (unsigned long long)buf; + eaddr = (unsigned long long)buf + offset; + readbytes = read(fd, buf, offset + MAX_INSN_SIZE); + if (readbytes != offset + MAX_INSN_SIZE) { + pr_warning("Failed to read %s: %s\n", name, strerror(errno)); + goto out; + } + while (saddr < eaddr) { + insn_init(&insn, (void *)saddr, class == ELFCLASS64); + insn_get_length(&insn); + saddr += insn.length; + } + ret = (saddr == eaddr); + +out: + if (buf) + free(buf); + + if (fd) + close(fd); + + return ret; +} diff --git a/tools/perf/util/include/linux/string.h b/tools/perf/util/include/linux/string.h index 3b2f590..9d5eb21 100644 --- a/tools/perf/util/include/linux/string.h +++ b/tools/perf/util/include/linux/string.h @@ -1 +1,2 @@ #include <string.h> +#include <perf.h> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index b7dec82..8f3de61 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2254,6 +2254,17 @@ int show_available_funcs(const char *target, struct strfilter *_filter, } /* + * Check if a given offset from start of a function is valid or not + */ +bool __attribute__((weak)) can_probe(char *name __used, + unsigned long long vaddr __used, + unsigned long offset __used, + u8 class __used) +{ + return true; +} + +/* * uprobe_events only accepts address: * Convert function and any offset to address */ @@ -2307,7 +2318,16 @@ static int convert_name_to_addr(struct perf_probe_event *pev, const char *exec) if (map->start > sym->start) vaddr = map->start; - vaddr += sym->start + pp->offset + map->pgoff; + + vaddr += sym->start + map->pgoff; + if (pp->offset) + if ((vaddr + pp->offset > sym->end) || + !can_probe(name, vaddr, pp->offset, + map->dso->class)) { + pr_err("Failed to insert probe, ensure offset is within function and on insn boundary.\n"); + return -EINVAL; + } + vaddr += pp->offset; pp->offset = 0; if (!pev->event) { diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index f9f3de8..af96594 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -137,4 +137,6 @@ extern int show_available_funcs(const char *module, struct strfilter *filter, /* Maximum index number of event-name postfix */ #define MAX_EVENT_INDEX 1024 +extern bool can_probe(char *name, unsigned long long vaddr, + unsigned long offset, u8 class); #endif /*_PROBE_EVENT_H */ diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index caaf75a..be58b06 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1184,6 +1184,7 @@ static int dso__load_sym(struct dso *dso, struct map *map, const char *name, goto out_close; } + dso->class = gelf_getclass(elf); if (gelf_getehdr(elf, &ehdr) == NULL) { pr_debug("%s: cannot get elf header.\n", __func__); goto out_elf_end; @@ -1326,6 +1327,7 @@ static int dso__load_sym(struct dso *dso, struct map *map, const char *name, curr_dso->kernel = dso->kernel; curr_dso->long_name = dso->long_name; curr_dso->long_name_len = dso->long_name_len; + curr_dso->class = dso->class; curr_map = map__new2(start, curr_dso, map->type); if (curr_map == NULL) { diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 9e7742c..1d0cc28 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -174,6 +174,7 @@ struct dso { char *long_name; u16 long_name_len; u16 short_name_len; + u8 class; char name[0]; }; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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