From: Michal Suchanek <msuchanek@suse.de>

Date: Wed, 7 Feb 2018 15:16:04 +0100

Subject: Add ksym-provides tool.

References: bsc#1077692

Patch-mainline: no, not needed

Signed-off-by: Michal Suchanek <msuchanek@suse.de>

---

 scripts/mod/Makefile        |   6 +-

 scripts/mod/ksym-provides.c | 124 ++++++++++++++++++++++++++++++++++++

 2 files changed, 129 insertions(+), 1 deletion(-)

 create mode 100644 scripts/mod/ksym-provides.c

--- a/scripts/mod/Makefile

+++ b/scripts/mod/Makefile

@@ -2,11 +2,15 @@

 OBJECT_FILES_NON_STANDARD := y

 CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO)

-hostprogs-always-y	+= modpost mk_elfconfig

+hostprogs-always-y	+= modpost mk_elfconfig ksym-provides

 always-y		+= empty.o

 modpost-objs	:= modpost.o file2alias.o sumversion.o

+ksym-provides-objs	:= ksym-provides.o

+

+HOSTLDLIBS_ksym-provides := -lelf

+

 devicetable-offsets-file := devicetable-offsets.h

 $(obj)/$(devicetable-offsets-file): $(obj)/devicetable-offsets.s FORCE

--- /dev/null

+++ b/scripts/mod/ksym-provides.c

@@ -0,0 +1,124 @@

+#include <stdio.h>

+#include <sys/types.h>

+#include <sys/stat.h>

+#include <fcntl.h>

+#include <unistd.h>

+#include <gelf.h>

+#include <string.h>

+

+int main(int argc, char *argv[])

+{

+	int fd;

+	Elf *elf;

+	Elf_Scn *scn;

+	GElf_Shdr shdr;

+	size_t strndx;

+	int ndx;

+	Elf_Data *symdata, *data;

+	GElf_Sym sym;

+	char *name;

+	const char * flavor = argv[1];

+	const char * prefix = "__crc_";

+	size_t prefixlen = strlen(prefix);

+	const char * symformat = "ksym(%s:%s) = %lx\n";

+

+	if (argc != 3) {

+		fprintf(stderr, "Usage: %s <flavor> <filename>\n", argv[0]);

+		return 1;

+	}

+

+	if (elf_version(EV_CURRENT) == EV_NONE) {

+		fprintf(stderr, "libelf initialization failed: %s\n",

+			elf_errmsg(-1));

+		return 1;

+	}

+

+	fd = open(argv[2], O_RDONLY);

+	if (fd < 0) {

+		perror("open failed");

+		return 1;

+	}

+

+	elf = elf_begin(fd, ELF_C_READ, NULL);

+	if (!elf) {

+		fprintf(stderr, "elf_begin failed: %s\n", elf_errmsg(-1));

+		goto err_close;

+	}

+

+	scn = NULL;

+	while ((scn = elf_nextscn(elf, scn)) != NULL) {

+		if (!gelf_getshdr(scn, &shdr)) {

+			fprintf(stderr, "gelf_getshdr failed: %s\n",

+				elf_errmsg(-1));

+			goto err_end;

+		}

+

+		if (shdr.sh_type == SHT_SYMTAB)

+			break;

+	}

+	if (!scn) {

+		fputs("symbol table not found\n", stderr);

+		goto err_end;

+	}

+	strndx = shdr.sh_link;

+

+	symdata = elf_getdata(scn, NULL);

+	if (!symdata) {

+		fprintf(stderr, "elf_getdata failed: %s\n", elf_errmsg(-1));

+		goto err_end;

+	}

+

+	for (ndx = 0; gelf_getsym(symdata, ndx, &sym) != NULL; ++ndx) {

+

+		name = elf_strptr(elf, strndx, sym.st_name);

+		if (!name) {

+			fprintf(stderr, "elf_strptr failed: %s\n",

+				elf_errmsg(-1));

+			goto err_end;

+		}

+		if (strncmp(prefix, name, prefixlen))

+			continue;

+

+		if (sym.st_shndx >= SHN_LORESERVE) {

+			printf(symformat, flavor, name + prefixlen,

+				sym.st_value);

+			continue;

+		}

+

+		scn = elf_getscn(elf, sym.st_shndx);

+		if (!scn) {

+			fprintf(stderr, "elf_getscn failed: %s\n",

+				elf_errmsg(-1));

+			goto err_end;

+		}

+		if (!gelf_getshdr(scn, &shdr)) {

+			fprintf(stderr, "gelf_getshdr failed: %s\n",

+				elf_errmsg(-1));

+			goto err_end;

+		}

+

+		if (shdr.sh_type != SHT_PROGBITS)

+			continue;

+

+		data = elf_getdata_rawchunk(

+			elf, shdr.sh_offset + sym.st_value - shdr.sh_addr,

+			sizeof(GElf_Word), ELF_T_WORD);

+		if (!data) {

+			fprintf(stderr, "elf_getdata_rawchunk failed: %s\n",

+				elf_errmsg(-1));

+			goto err_end;

+		}

+		printf(symformat, flavor, name + prefixlen,

+		       (unsigned long) *(GElf_Word*)data->d_buf);

+	}

+

+	elf_end(elf);

+	close(fd);

+	return 0;

+

+ err_end:

+	elf_end(elf);

+ err_close:

+	close(fd);

+	return 1;

+}