Attachment 307190 Details for Bug 447863 – Fix marker/stap interface

Fix marker/stap interface

m1.patch (text/plain), 9.77 KB, created by IBM Bug Proxy on 2008-05-30 12:16:37 UTC

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Creator: IBM Bug Proxy

Created: 2008-05-30 12:16:37 UTC

Size: 9.77 KB

patch

obsolete

>>From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>
>This adds some new magic in the MODPOST phase for CONFIG_MARKERS.  Analogous
>to the Module.symvers file, the build will now write a Module.markers file
>when CONFIG_MARKERS=y is set.  This file lists the name, defining module, and
>format string of each marker, separated by \t characters.  This simple text
>file can be used by offline build procedures for instrumentation code,
>analogous to how System.map and Module.symvers can be useful to have for
>kernels other than the one you are running right now.
>
>The strings are made easy to extract by having the __trace_mark macro define
>the name and format together in a single array called __mstrtab_* in the
>__markers_strings section.  This is straightforward and reliable as long as
>the marker structs are always defined by this macro.  It is an unreasonable
>amount of hairy work to extract the string pointers from the __markers section
>structs, which entails handling a relocation type for every machine under the
>sun.
>
>Mathieu :
>- Ran through checkpatch.pl
>
>Signed-off-by: Roland McGrath <roland@redhat.com>
>Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>Cc: David Smith <dsmith@redhat.com>
>Cc: Sam Ravnborg <sam@ravnborg.org>
>Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>---
>
> include/linux/marker.h   |    9 --
> scripts/Makefile.modpost |   11 ++
> scripts/mod/modpost.c    |  164 ++++++++++++++++++++++++++++++++++++-
> scripts/mod/modpost.h    |    3 
> 4 files changed, 180 insertions(+), 7 deletions(-)
>
>Index: linux-2.6.24.7-ibmrt2.3-view/scripts/Makefile.modpost
>===================================================================
>--- linux-2.6.24.7-ibmrt2.3-view.orig/scripts/Makefile.modpost
>+++ linux-2.6.24.7-ibmrt2.3-view/scripts/Makefile.modpost
>@@ -13,6 +13,7 @@
> # 2) modpost is then used to
> # 3)  create one <module>.mod.c file pr. module
> # 4)  create one Module.symvers file with CRC for all exported symbols
>+# 4a) [CONFIG_MARKERS] create one Module.markers file listing defined markers
> # 5) compile all <module>.mod.c files
> # 6) final link of the module to a <module.ko> file
> 
>@@ -45,6 +46,10 @@ include scripts/Makefile.lib
> 
> kernelsymfile := $(objtree)/Module.symvers
> modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
>+kernelmarkersfile := $(objtree)/Module.markers
>+modulemarkersfile := $(firstword $(KBUILD_EXTMOD))/Module.markers
>+
>+markersfile = $(if $(KBUILD_EXTMOD),$(modulemarkersfile),$(kernelmarkersfile))
> 
> # Step 1), find all modules listed in $(MODVERDIR)/
> __modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
>@@ -65,6 +70,8 @@ modpost = scripts/mod/modpost           
>  $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)   \
>  $(if $(KBUILD_EXTMOD),-I $(modulesymfile))      \
>  $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
>+ $(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \
>+ $(if $(CONFIG_MARKERS),-M $(markersfile))     \
>  $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
>  $(if $(cross_build),-c)
> 
>@@ -85,6 +92,10 @@ vmlinux.o: FORCE
> $(symverfile):         __modpost ;
> $(modules:.ko=.mod.c): __modpost ;
> 
>+ifdef CONFIG_MARKERS
>+$(markersfile):	       __modpost ;
>+endif
>+
> 
> # Step 5), compile all *.mod.c files
> 
>Index: linux-2.6.24.7-ibmrt2.3-view/scripts/mod/modpost.c
>===================================================================
>--- linux-2.6.24.7-ibmrt2.3-view.orig/scripts/mod/modpost.c
>+++ linux-2.6.24.7-ibmrt2.3-view/scripts/mod/modpost.c
>@@ -11,6 +11,8 @@
>  * Usage: modpost vmlinux module1.o module2.o ...
>  */
> 
>+#define _GNU_SOURCE
>+#include <stdio.h>
> #include <ctype.h>
> #include "modpost.h"
> #include "../../include/linux/license.h"
>@@ -424,6 +426,8 @@ static int parse_elf(struct elf_info *in
> 			info->export_unused_gpl_sec = i;
> 		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
> 			info->export_gpl_future_sec = i;
>+		else if (strcmp(secname, "__markers_strings") == 0)
>+			info->markers_strings_sec = i;
> 
> 		if (sechdrs[i].sh_type != SHT_SYMTAB)
> 			continue;
>@@ -1249,6 +1253,62 @@ static int exit_section_ref_ok(const cha
> 	return 0;
> }
> 
>+static void get_markers(struct elf_info *info, struct module *mod)
>+{
>+	const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec];
>+	const char *strings = (const char *) info->hdr + sh->sh_offset;
>+	const Elf_Sym *sym, *first_sym, *last_sym;
>+	size_t n;
>+
>+	if (!info->markers_strings_sec)
>+		return;
>+
>+	/*
>+	 * First count the strings.  We look for all the symbols defined
>+	 * in the __markers_strings section named __mstrtab_*.  For
>+	 * these local names, the compiler puts a random .NNN suffix on,
>+	 * so the names don't correspond exactly.
>+	 */
>+	first_sym = last_sym = NULL;
>+	n = 0;
>+	for (sym = info->symtab_start; sym < info->symtab_stop; sym++)
>+		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
>+		    sym->st_shndx == info->markers_strings_sec &&
>+		    !strncmp(info->strtab + sym->st_name,
>+			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
>+			if (first_sym == NULL)
>+				first_sym = sym;
>+			last_sym = sym;
>+			++n;
>+		}
>+
>+	if (n == 0)
>+		return;
>+
>+	/*
>+	 * Now collect each name and format into a line for the output.
>+	 * Lines look like:
>+	 *	marker_name	vmlinux	marker %s format %d
>+	 * The format string after the second \t can use whitespace.
>+	 */
>+	mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n));
>+	mod->nmarkers = n;
>+
>+	n = 0;
>+	for (sym = first_sym; sym <= last_sym; sym++)
>+		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
>+		    sym->st_shndx == info->markers_strings_sec &&
>+		    !strncmp(info->strtab + sym->st_name,
>+			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
>+			const char *name = strings + sym->st_value;
>+			const char *fmt = strchr(name, '\0') + 1;
>+			char *line = NULL;
>+			asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
>+			NOFAIL(line);
>+			mod->markers[n++] = line;
>+		}
>+}
>+
> static void read_symbols(char *modname)
> {
> 	const char *symname;
>@@ -1301,6 +1361,8 @@ static void read_symbols(char *modname)
> 		get_src_version(modname, mod->srcversion,
> 				sizeof(mod->srcversion)-1);
> 
>+	get_markers(&info, mod);
>+
> 	parse_elf_finish(&info);
> 
> 	/* Our trick to get versioning for struct_module - it's
>@@ -1649,6 +1711,92 @@ static void write_dump(const char *fname
> 	write_if_changed(&buf, fname);
> }
> 
>+static void add_marker(struct module *mod, const char *name, const char *fmt)
>+{
>+	char *line = NULL;
>+	asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
>+	NOFAIL(line);
>+
>+	mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) *
>+						     sizeof mod->markers[0])));
>+	mod->markers[mod->nmarkers++] = line;
>+}
>+
>+static void read_markers(const char *fname)
>+{
>+	unsigned long size, pos = 0;
>+	void *file = grab_file(fname, &size);
>+	char *line;
>+
>+	if (!file)		/* No old markers, silently ignore */
>+		return;
>+
>+	while ((line = get_next_line(&pos, file, size))) {
>+		char *marker, *modname, *fmt;
>+		struct module *mod;
>+
>+		marker = line;
>+		modname = strchr(marker, '\t');
>+		if (!modname)
>+			goto fail;
>+		*modname++ = '\0';
>+		fmt = strchr(modname, '\t');
>+		if (!fmt)
>+			goto fail;
>+		*fmt++ = '\0';
>+		if (*marker == '\0' || *modname == '\0')
>+			goto fail;
>+
>+		mod = find_module(modname);
>+		if (!mod) {
>+			if (is_vmlinux(modname))
>+				have_vmlinux = 1;
>+			mod = new_module(NOFAIL(strdup(modname)));
>+			mod->skip = 1;
>+		}
>+
>+		add_marker(mod, marker, fmt);
>+	}
>+	return;
>+fail:
>+	fatal("parse error in markers list file\n");
>+}
>+
>+static int compare_strings(const void *a, const void *b)
>+{
>+	return strcmp(*(const char **) a, *(const char **) b);
>+}
>+
>+static void write_markers(const char *fname)
>+{
>+	struct buffer buf = { };
>+	struct module *mod;
>+	size_t i;
>+
>+	for (mod = modules; mod; mod = mod->next)
>+		if ((!external_module || !mod->skip) && mod->markers != NULL) {
>+			/*
>+			 * Sort the strings so we can skip duplicates when
>+			 * we write them out.
>+			 */
>+			qsort(mod->markers, mod->nmarkers,
>+			      sizeof mod->markers[0], &compare_strings);
>+			for (i = 0; i < mod->nmarkers; ++i) {
>+				char *line = mod->markers[i];
>+				buf_write(&buf, line, strlen(line));
>+				while (i + 1 < mod->nmarkers &&
>+				       !strcmp(mod->markers[i],
>+					       mod->markers[i + 1]))
>+					free(mod->markers[i++]);
>+				free(mod->markers[i]);
>+			}
>+			free(mod->markers);
>+			mod->markers = NULL;
>+		}
>+
>+	write_if_changed(&buf, fname);
>+}
>+
> int main(int argc, char **argv)
> {
> 	struct module *mod;
>@@ -1656,10 +1804,13 @@ int main(int argc, char **argv)
> 	char fname[SZ];
> 	char *kernel_read = NULL, *module_read = NULL;
> 	char *dump_write = NULL;
>+	char *markers_read = NULL;
>+	char *markers_write = NULL;
>+
> 	int opt;
> 	int err;
> 
>-	while ((opt = getopt(argc, argv, "i:I:cmso:aw")) != -1) {
>+	while ((opt = getopt(argc, argv, "i:I:mso:awM:K:")) != -1) {
> 		switch(opt) {
> 			case 'i':
> 				kernel_read = optarg;
>@@ -1686,6 +1837,12 @@ int main(int argc, char **argv)
> 			case 'w':
> 				warn_unresolved = 1;
> 				break;
>+			case 'M':
>+				markers_write = optarg;
>+				break;
>+			case 'K':
>+				markers_read = optarg;
>+				break;
> 			default:
> 				exit(1);
> 		}
>@@ -1727,5 +1884,11 @@ int main(int argc, char **argv)
> 	if (dump_write)
> 		write_dump(dump_write);
> 
>+	if (markers_read)
>+		read_markers(markers_read);
>+
>+	if (markers_write)
>+		write_markers(markers_write);
>+
> 	return err;
> }
>Index: linux-2.6.24.7-ibmrt2.3-view/scripts/mod/modpost.h
>===================================================================
>--- linux-2.6.24.7-ibmrt2.3-view.orig/scripts/mod/modpost.h
>+++ linux-2.6.24.7-ibmrt2.3-view/scripts/mod/modpost.h
>@@ -110,6 +110,8 @@ struct module {
> 	int has_init;
> 	int has_cleanup;
> 	struct buffer dev_table_buf;
>+	char **markers;
>+	size_t nmarkers;
> 	char	     srcversion[25];
> };
> 
>@@ -124,6 +126,7 @@ struct elf_info {
> 	Elf_Section  export_gpl_sec;
> 	Elf_Section  export_unused_gpl_sec;
> 	Elf_Section  export_gpl_future_sec;
>+	Elf_Section  markers_strings_sec;
> 	const char   *strtab;
> 	char	     *modinfo;
> 	unsigned int modinfo_len;

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Attachments on bug 447863: 307190