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Fix for Linux 4.10 commit 7fd8329ba502ef76dd91db561c7aed696b2c7720 
"taint/module: Clean up global and module taint flags handling".
Without the patch, when running against Linux 4.10-rc1 and later
kernels, the crash utility fails during session initialization with
the message "crash: invalid structure size: tnt".
(panand@redhat.com)
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Dave Anderson committed Jan 5, 2017
1 parent 58225d5 commit 24a6962
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Showing 3 changed files with 164 additions and 3 deletions.
4 changes: 3 additions & 1 deletion defs.h
View file
Expand Up @@ -2,7 +2,7 @@
*
* Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2016 David Anderson
* Copyright (C) 2002-2016 Red Hat, Inc. All rights reserved.
* Copyright (C) 2002-2017 Red Hat, Inc. All rights reserved.
* Copyright (C) 2002 Silicon Graphics, Inc.
*
* This program is free software; you can redistribute it and/or modify
Expand Down Expand Up @@ -1977,6 +1977,7 @@ struct offset_table { /* stash of commonly-used offsets */
long blk_mq_ctx_rq_dispatched;
long blk_mq_ctx_rq_completed;
long task_struct_stack;
long tnt_mod;
};

struct size_table { /* stash of commonly-used sizes */
Expand Down Expand Up @@ -2120,6 +2121,7 @@ struct size_table { /* stash of commonly-used sizes */
long trace_print_flags;
long task_struct_flags;
long timer_base;
long taint_flag;
};

struct array_table {
Expand Down
158 changes: 157 additions & 1 deletion kernel.c
View file
Expand Up @@ -2,7 +2,7 @@
*
* Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2016 David Anderson
* Copyright (C) 2002-2016 Red Hat, Inc. All rights reserved.
* Copyright (C) 2002-2017 Red Hat, Inc. All rights reserved.
*
* 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
Expand All @@ -21,6 +21,7 @@
#include <elf.h>
#include <libgen.h>
#include <ctype.h>
#include <stdbool.h>

static void do_module_cmd(ulong, char *, ulong, char *, char *);
static void show_module_taint(void);
Expand Down Expand Up @@ -3962,6 +3963,99 @@ check_specified_module_tree(char *module, char *gdb_buffer)
return retval;
}

static void
show_module_taint_4_10(void)
{
int i, j, bx;
struct load_module *lm;
int maxnamelen;
int found;
char buf1[BUFSIZE];
char buf2[BUFSIZE];
struct syment *sp;
uint *taintsp, taints;
bool tnt_mod;
char tnt_true;
int tnts_len;
ulong tnts_addr;
char *modbuf;

if (INVALID_MEMBER(module_taints)) {
MEMBER_OFFSET_INIT(module_taints, "module", "taints");
STRUCT_SIZE_INIT(taint_flag, "taint_flag");
MEMBER_OFFSET_INIT(tnt_true, "taint_flag", "true");
MEMBER_OFFSET_INIT(tnt_mod, "taint_flag", "module");
}

modbuf = GETBUF(SIZE(module));

for (i = found = maxnamelen = 0; i < kt->mods_installed; i++) {
lm = &st->load_modules[i];

readmem(lm->module_struct, KVADDR, modbuf, SIZE(module),
"module struct", FAULT_ON_ERROR);

taints = ULONG(modbuf + OFFSET(module_taints));

if (taints) {
found++;
maxnamelen = strlen(lm->mod_name) > maxnamelen ?
strlen(lm->mod_name) : maxnamelen;
}
}

if (!found) {
fprintf(fp, "no tainted modules\n");
FREEBUF(modbuf);
return;
}

tnts_len = get_array_length("taint_flags", NULL, 0);
sp = symbol_search("taint_flags");
tnts_addr = sp->value;

fprintf(fp, "%s %s\n",
mkstring(buf2, maxnamelen, LJUST, "NAME"), "TAINTS");

for (i = 0; i < st->mods_installed; i++) {

lm = &st->load_modules[i];
bx = 0;
buf1[0] = '\0';

readmem(lm->module_struct, KVADDR, modbuf, SIZE(module),
"module struct", FAULT_ON_ERROR);

taints = ULONG(modbuf + OFFSET(module_taints));
if (!taints)
continue;
taintsp = &taints;

for (j = 0; j < tnts_len; j++) {
readmem((tnts_addr + j * SIZE(taint_flag)) +
OFFSET(tnt_mod),
KVADDR, &tnt_mod, sizeof(bool),
"tnt mod", FAULT_ON_ERROR);
if (!tnt_mod)
continue;
if (NUM_IN_BITMAP(taintsp, j)) {
readmem((tnts_addr + j * SIZE(taint_flag)) +
OFFSET(tnt_true),
KVADDR, &tnt_true, sizeof(char),
"tnt true", FAULT_ON_ERROR);
buf1[bx++] = tnt_true;
}
}

buf1[bx++] = '\0';

fprintf(fp, "%s %s\n", mkstring(buf2, maxnamelen,
LJUST, lm->mod_name), buf1);
}

FREEBUF(modbuf);
}

static void
show_module_taint(void)
{
Expand All @@ -3980,6 +4074,12 @@ show_module_taint(void)
ulong tnts_addr;
char *modbuf;

if (VALID_STRUCT(taint_flag) ||
(kernel_symbol_exists("taint_flags") && STRUCT_EXISTS("taint_flag"))) {
show_module_taint_4_10();
return;
}

if (INVALID_MEMBER(module_taints) &&
INVALID_MEMBER(module_license_gplok)) {
MEMBER_OFFSET_INIT(module_taints, "module", "taints");
Expand Down Expand Up @@ -10415,6 +10515,56 @@ dump_variable_length_record(void)
hq_close();
}

static void
show_kernel_taints_v4_10(char *buf, int verbose)
{
int i, bx;
char tnt_true, tnt_false;
int tnts_len;
ulong tnts_addr;
ulong tainted_mask, *tainted_mask_ptr;
struct syment *sp;

if (!VALID_STRUCT(taint_flag)) {
STRUCT_SIZE_INIT(taint_flag, "taint_flag");
MEMBER_OFFSET_INIT(tnt_true, "taint_flag", "true");
MEMBER_OFFSET_INIT(tnt_false, "taint_flag", "false");
}

tnts_len = get_array_length("taint_flags", NULL, 0);
sp = symbol_search("taint_flags");
tnts_addr = sp->value;

bx = 0;
buf[0] = '\0';

get_symbol_data("tainted_mask", sizeof(ulong), &tainted_mask);
tainted_mask_ptr = &tainted_mask;

for (i = 0; i < tnts_len; i++) {
if (NUM_IN_BITMAP(tainted_mask_ptr, i)) {
readmem((tnts_addr + i * SIZE(taint_flag)) +
OFFSET(tnt_true),
KVADDR, &tnt_true, sizeof(char),
"tnt true", FAULT_ON_ERROR);
buf[bx++] = tnt_true;
} else {
readmem((tnts_addr + i * SIZE(taint_flag)) +
OFFSET(tnt_false),
KVADDR, &tnt_false, sizeof(char),
"tnt false", FAULT_ON_ERROR);
if (tnt_false != ' ' && tnt_false != '-' &&
tnt_false != 'G')
buf[bx++] = tnt_false;
}
}

buf[bx++] = '\0';

if (verbose)
fprintf(fp, "TAINTED_MASK: %lx %s\n", tainted_mask, buf);
}

static void
show_kernel_taints(char *buf, int verbose)
{
Expand All @@ -10427,6 +10577,12 @@ show_kernel_taints(char *buf, int verbose)
int tainted;
struct syment *sp;

if (VALID_STRUCT(taint_flag) ||
(kernel_symbol_exists("taint_flags") && STRUCT_EXISTS("taint_flag"))) {
show_kernel_taints_v4_10(buf, verbose);
return;
}

if (!VALID_STRUCT(tnt)) {
STRUCT_SIZE_INIT(tnt, "tnt");
MEMBER_OFFSET_INIT(tnt_bit, "tnt", "bit");
Expand Down
5 changes: 4 additions & 1 deletion symbols.c
View file
Expand Up @@ -2,7 +2,7 @@
*
* Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2016 David Anderson
* Copyright (C) 2002-2016 Red Hat, Inc. All rights reserved.
* Copyright (C) 2002-2017 Red Hat, Inc. All rights reserved.
*
* 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
Expand Down Expand Up @@ -8897,6 +8897,7 @@ dump_offset_table(char *spec, ulong makestruct)
fprintf(fp, " tnt_bit: %ld\n", OFFSET(tnt_bit));
fprintf(fp, " tnt_true: %ld\n", OFFSET(tnt_true));
fprintf(fp, " tnt_false: %ld\n", OFFSET(tnt_false));
fprintf(fp, " tnt_mod: %ld\n", OFFSET(tnt_mod));

fprintf(fp, " page_next: %ld\n", OFFSET(page_next));
fprintf(fp, " page_prev: %ld\n", OFFSET(page_prev));
Expand Down Expand Up @@ -10348,6 +10349,8 @@ dump_offset_table(char *spec, ulong makestruct)
SIZE(timer_base));
fprintf(fp, " tnt: %ld\n",
SIZE(tnt));
fprintf(fp, " taint_flag: %ld\n",
SIZE(taint_flag));

fprintf(fp, "\n array_table:\n");
/*
Expand Down

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