Em Tue, Apr 24, 2012 at 12:06:46PM +0530, Prashanth Nageshappa escreveu: > 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. Some minor nits below > --- /dev/null > +++ b/tools/perf/arch/x86/util/probe-event.c > @@ -0,0 +1,84 @@ > +bool can_probe(char *name, unsigned long long vaddr, unsigned long offset, > + u8 class) > +{ > + unsigned long long eaddr, saddr; Why not the much shorter 'u64'? > + 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); No need to cast malloc's return > + 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; Goto out_close and... > + } > + 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; out_close > + } > + 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); free can handle NULL pointers just fine > + > + if (fd) > + close(fd); You can move this to before 'free' and label it out_close, avoiding the test. > + > + 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; > + } Multi line if bodies gets visually nicer when enclosed with {} > + 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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