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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /tools/objtool/klp-checksum.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'tools/objtool/klp-checksum.c')
-rw-r--r--tools/objtool/klp-checksum.c347
1 files changed, 347 insertions, 0 deletions
diff --git a/tools/objtool/klp-checksum.c b/tools/objtool/klp-checksum.c
new file mode 100644
index 000000000..b8e47f289
--- /dev/null
+++ b/tools/objtool/klp-checksum.c
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <string.h>
+#include <subcmd/parse-options.h>
+
+#include <objtool/arch.h>
+#include <objtool/builtin.h>
+#include <objtool/check.h>
+#include <objtool/elf.h>
+#include <objtool/klp.h>
+#include <objtool/objtool.h>
+#include <objtool/warn.h>
+#include <objtool/checksum.h>
+
+static int checksum_debug_init(struct objtool_file *file)
+{
+ char *dup, *s;
+
+ if (!opts.debug_checksum)
+ return 0;
+
+ dup = strdup(opts.debug_checksum);
+ if (!dup) {
+ ERROR_GLIBC("strdup");
+ return -1;
+ }
+
+ s = dup;
+ while (*s) {
+ bool found = false;
+ struct symbol *sym;
+ char *comma;
+
+ comma = strchr(s, ',');
+ if (comma)
+ *comma = '\0';
+
+ for_each_sym_by_name(file->elf, s, sym) {
+ if (!is_func_sym(sym) && !is_object_sym(sym))
+ continue;
+ sym->debug_checksum = 1;
+ found = true;
+ }
+
+ if (!found)
+ WARN("--debug-checksum: can't find '%s'", s);
+
+ if (!comma)
+ break;
+
+ s = comma + 1;
+ }
+
+ free(dup);
+ return 0;
+}
+
+static void checksum_update_insn(struct objtool_file *file, struct symbol *func,
+ struct instruction *insn)
+{
+ struct reloc *reloc = insn_reloc(file, insn);
+ struct alternative *alt;
+ unsigned long offset;
+ struct symbol *sym;
+ static bool in_alt;
+
+ if (insn->fake)
+ return;
+
+ if (!reloc) {
+ struct symbol *call_dest = insn_call_dest(insn);
+ struct instruction *jump_dest = insn->jump_dest;
+
+ /*
+ * For a jump/call non-relocated dest offset embedded in the
+ * instruction, the offset may vary due to changes in
+ * surrounding code. Just hash the opcode and a
+ * position-independent representation of the destination.
+ */
+
+ if (call_dest || jump_dest) {
+ unsigned char buf[16];
+ size_t len;
+
+ len = arch_jump_opcode_bytes(file, insn, buf);
+ __checksum_update_insn(func, insn, buf, len);
+
+ if (call_dest) {
+ __checksum_update_insn(func, insn, call_dest->demangled_name,
+ strlen(call_dest->demangled_name));
+
+ } else if (jump_dest) {
+ struct symbol *dest_sym;
+ unsigned long offset;
+
+ /*
+ * use insn->_sym instead of insn_sym() here.
+ * For alternative replacements, the latter
+ * would give the function of the code being
+ * replaced.
+ */
+ dest_sym = jump_dest->_sym;
+ if (!dest_sym)
+ goto alts;
+
+ __checksum_update_insn(func, insn, dest_sym->demangled_name,
+ strlen(dest_sym->demangled_name));
+
+ offset = jump_dest->offset - dest_sym->offset;
+ __checksum_update_insn(func, insn, &offset, sizeof(offset));
+ }
+
+ goto alts;
+ }
+ }
+
+ __checksum_update_insn(func, insn, insn->sec->data->d_buf + insn->offset, insn->len);
+
+ if (!reloc)
+ goto alts;
+
+ sym = reloc->sym;
+ offset = arch_insn_adjusted_addend(insn, reloc);
+
+ if (is_string_sec(sym->sec)) {
+ char *str;
+
+ str = sym->sec->data->d_buf + sym->offset + offset;
+ __checksum_update_insn(func, insn, str, strlen(str));
+ goto alts;
+ }
+
+ if (is_sec_sym(sym)) {
+ sym = find_symbol_containing(reloc->sym->sec, offset);
+ if (!sym)
+ goto alts;
+
+ offset -= sym->offset;
+ }
+
+ __checksum_update_insn(func, insn, sym->demangled_name,
+ strlen(sym->demangled_name));
+ __checksum_update_insn(func, insn, &offset, sizeof(offset));
+
+alts:
+ for (alt = insn->alts; alt; alt = alt->next) {
+ struct alt_group *alt_group = alt->insn->alt_group;
+
+ /* Prevent __ex_table recursion, e.g. LOAD_SEGMENT() */
+ if (in_alt)
+ break;
+ in_alt = true;
+
+ __checksum_update_insn(func, insn, &alt->type,
+ sizeof(alt->type));
+
+ if (alt_group && alt_group->orig_group) {
+ struct instruction *alt_insn;
+
+ __checksum_update_insn(func, insn, &alt_group->feature,sizeof(alt_group->feature));
+
+ for (alt_insn = alt->insn; alt_insn; alt_insn = next_insn_same_sec(file, alt_insn)) {
+ checksum_update_insn(file, func, alt_insn);
+ if (!alt_group->last_insn || alt_insn == alt_group->last_insn)
+ break;
+ }
+ } else {
+ checksum_update_insn(file, func, alt->insn);
+ }
+
+ in_alt = false;
+ }
+}
+
+static void checksum_update_object(struct objtool_file *file, struct symbol *sym)
+{
+ struct reloc *reloc;
+
+ __checksum_update_object(sym, 0, "len", &sym->len, sizeof(sym->len));
+
+ if (sym->sec->data->d_buf)
+ __checksum_update_object(sym, 0, "data",
+ sym->sec->data->d_buf + sym->offset,
+ sym->len);
+
+ sym_for_each_reloc(file->elf, sym, reloc) {
+ unsigned long sym_offset = reloc_offset(reloc) - sym->offset;
+ struct symbol *target = reloc->sym;
+ s64 offset;
+
+ offset = reloc_addend(reloc);
+
+ if (is_string_sec(target->sec)) {
+ char *str;
+
+ str = target->sec->data->d_buf + target->offset + offset;
+ __checksum_update_object(sym, sym_offset,
+ "reloc string", str, strlen(str));
+ continue;
+ }
+
+ if (is_sec_sym(target)) {
+ target = find_symbol_containing(reloc->sym->sec, offset);
+ if (!target)
+ continue;
+
+ offset -= target->offset;
+ }
+
+ __checksum_update_object(sym, sym_offset, "reloc name",
+ target->demangled_name,
+ strlen(target->demangled_name));
+ __checksum_update_object(sym, sym_offset, "reloc addend",
+ &offset, sizeof(offset));
+ }
+}
+
+int calculate_checksums(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct symbol *sym;
+
+ if (checksum_debug_init(file))
+ return -1;
+
+ for_each_sym(file->elf, sym) {
+
+ /*
+ * Skip cold subfunctions and aliases: they share the
+ * parent's checksum via func_for_each_insn() which
+ * follows func->cfunc into the cold subfunction.
+ */
+ if (is_cold_func(sym) || is_alias_sym(sym) || !sym->len ||
+ !sym->sec || !sym->sec->data)
+ continue;
+
+ if (is_func_sym(sym)) {
+ checksum_init(sym);
+ func_for_each_insn(file, sym, insn)
+ checksum_update_insn(file, sym, insn);
+ checksum_finish(sym);
+
+ } else if (is_object_sym(sym)) {
+ checksum_init(sym);
+ checksum_update_object(file, sym);
+ checksum_finish(sym);
+ }
+
+ }
+
+ return 0;
+}
+
+int create_sym_checksum_section(struct objtool_file *file)
+{
+ struct section *sec;
+ struct symbol *sym;
+ unsigned int idx = 0;
+ struct sym_checksum *checksum;
+ size_t entsize = sizeof(struct sym_checksum);
+
+ sec = find_section_by_name(file->elf, ".discard.sym_checksum");
+ if (sec) {
+ if (!opts.dryrun)
+ WARN("file already has .discard.sym_checksum section, skipping");
+
+ return 0;
+ }
+
+ for_each_sym(file->elf, sym)
+ if (sym->csum.checksum)
+ idx++;
+
+ sec = elf_create_section_pair(file->elf, ".discard.sym_checksum", entsize,
+ idx, idx);
+ if (!sec)
+ return -1;
+
+ idx = 0;
+ for_each_sym(file->elf, sym) {
+ if (!sym->csum.checksum)
+ continue;
+
+ if (!elf_init_reloc(file->elf, sec->rsec, idx, idx * entsize,
+ sym, 0, R_TEXT64))
+ return -1;
+
+ checksum = (struct sym_checksum *)sec->data->d_buf + idx;
+ checksum->addr = 0; /* reloc */
+ checksum->checksum = sym->csum.checksum;
+
+ mark_sec_changed(file->elf, sec, true);
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static const char * const klp_checksum_usage[] = {
+ "objtool klp checksum [<options>] file.o",
+ NULL,
+};
+
+int cmd_klp_checksum(int argc, const char **argv)
+{
+ struct objtool_file *file;
+ int ret;
+
+ const struct option options[] = {
+ OPT_STRING(0, "debug-checksum", &opts.debug_checksum, "syms", "enable checksum debug output"),
+ OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"),
+ OPT_END(),
+ };
+
+ argc = parse_options(argc, argv, options, klp_checksum_usage, 0);
+ if (argc != 1)
+ usage_with_options(klp_checksum_usage, options);
+
+ opts.checksum = true;
+
+ objname = argv[0];
+
+ file = objtool_open_read(objname);
+ if (!file)
+ return 1;
+
+ ret = decode_file(file);
+ if (ret)
+ goto out;
+
+ ret = calculate_checksums(file);
+ if (ret)
+ goto out;
+
+ ret = create_sym_checksum_section(file);
+
+out:
+ free_insns(file);
+
+ if (ret)
+ return ret;
+
+ if (!opts.dryrun && file->elf->changed && elf_write(file->elf))
+ return 1;
+
+ return elf_close(file->elf);
+}