[PATCH 4.14 094/124] kdb: print real address of pointers instead of hashed addresses

Greg Kroah-Hartman
2018-11-19T16:50:53Z

From: Christophe Leroy <christophe.leroy@c-s.fr>

commit 568fb6f42ac6851320adaea25f8f1b94de14e40a upstream.

Since commit ad67b74d2469 ("printk: hash addresses printed with %p"),
all pointers printed with %p are printed with hashed addresses
instead of real addresses in order to avoid leaking addresses in
dmesg and syslog. But this applies to kdb too, with is unfortunate:

Entering kdb (current=0x(ptrval), pid 329) due to Keyboard Entry
kdb> ps
15 sleeping system daemon (state M) processes suppressed,
use 'ps A' to see all.
Task Addr Pid Parent [*] cpu State Thread Command
0x(ptrval) 329 328 1 0 R 0x(ptrval) *sh

0x(ptrval) 1 0 0 0 S 0x(ptrval) init
0x(ptrval) 3 2 0 0 D 0x(ptrval) rcu_gp
0x(ptrval) 4 2 0 0 D 0x(ptrval) rcu_par_gp
0x(ptrval) 5 2 0 0 D 0x(ptrval) kworker/0:0
0x(ptrval) 6 2 0 0 D 0x(ptrval) kworker/0:0H
0x(ptrval) 7 2 0 0 D 0x(ptrval) kworker/u2:0
0x(ptrval) 8 2 0 0 D 0x(ptrval) mm_percpu_wq
0x(ptrval) 10 2 0 0 D 0x(ptrval) rcu_preempt

The whole purpose of kdb is to debug, and for debugging real addresses
need to be known. In addition, data displayed by kdb doesn't go into
dmesg.

This patch replaces all %p by %px in kdb in order to display real
addresses.

Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/debug/kdb/kdb_main.c | 14 +++++++-------
kernel/debug/kdb/kdb_support.c | 12 ++++++------
2 files changed, 13 insertions(+), 13 deletions(-)

--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1182,7 +1182,7 @@ static int kdb_local(kdb_reason_t reason
if (reason == KDB_REASON_DEBUG) {
/* special case below */
} else {
- kdb_printf("\nEntering kdb (current=0x%p, pid %d) ",
+ kdb_printf("\nEntering kdb (current=0x%px, pid %d) ",
kdb_current, kdb_current ? kdb_current->pid : 0);
#if defined(CONFIG_SMP)
kdb_printf("on processor %d ", raw_smp_processor_id());
@@ -1198,7 +1198,7 @@ static int kdb_local(kdb_reason_t reason
*/
switch (db_result) {
case KDB_DB_BPT:
- kdb_printf("\nEntering kdb (0x%p, pid %d) ",
+ kdb_printf("\nEntering kdb (0x%px, pid %d) ",
kdb_current, kdb_current->pid);
#if defined(CONFIG_SMP)
kdb_printf("on processor %d ", raw_smp_processor_id());
@@ -2037,7 +2037,7 @@ static int kdb_lsmod(int argc, const cha
if (mod->state == MODULE_STATE_UNFORMED)
continue;

- kdb_printf("%-20s%8u 0x%p ", mod->name,
+ kdb_printf("%-20s%8u 0x%px ", mod->name,
mod->core_layout.size, (void *)mod);
#ifdef CONFIG_MODULE_UNLOAD
kdb_printf("%4d ", module_refcount(mod));
@@ -2048,7 +2048,7 @@ static int kdb_lsmod(int argc, const cha
kdb_printf(" (Loading)");
else
kdb_printf(" (Live)");
- kdb_printf(" 0x%p", mod->core_layout.base);
+ kdb_printf(" 0x%px", mod->core_layout.base);

#ifdef CONFIG_MODULE_UNLOAD
{
@@ -2330,7 +2330,7 @@ void kdb_ps1(const struct task_struct *p
return;

cpu = kdb_process_cpu(p);
- kdb_printf("0x%p %8d %8d %d %4d %c 0x%p %c%s\n",
+ kdb_printf("0x%px %8d %8d %d %4d %c 0x%px %c%s\n",
(void *)p, p->pid, p->parent->pid,
kdb_task_has_cpu(p), kdb_process_cpu(p),
kdb_task_state_char(p),
@@ -2343,7 +2343,7 @@ void kdb_ps1(const struct task_struct *p
} else {
if (KDB_TSK(cpu) != p)
kdb_printf(" Error: does not match running "
- "process table (0x%p)\n", KDB_TSK(cpu));
+ "process table (0x%px)\n", KDB_TSK(cpu));
}
}
}
@@ -2722,7 +2722,7 @@ int kdb_register_flags(char *cmd,
for_each_kdbcmd(kp, i) {
if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
kdb_printf("Duplicate kdb command registered: "
- "%s, func %p help %s\n", cmd, func, help);
+ "%s, func %px help %s\n", cmd, func, help);
return 1;
}
}
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -40,7 +40,7 @@
int kdbgetsymval(const char *symname, kdb_symtab_t *symtab)
{
if (KDB_DEBUG(AR))
- kdb_printf("kdbgetsymval: symname=%s, symtab=%p\n", symname,
+ kdb_printf("kdbgetsymval: symname=%s, symtab=%px\n", symname,
symtab);
memset(symtab, 0, sizeof(*symtab));
symtab->sym_start = kallsyms_lookup_name(symname);
@@ -88,7 +88,7 @@ int kdbnearsym(unsigned long addr, kdb_s
char *knt1 = NULL;

if (KDB_DEBUG(AR))
- kdb_printf("kdbnearsym: addr=0x%lx, symtab=%p\n", addr, symtab);
+ kdb_printf("kdbnearsym: addr=0x%lx, symtab=%px\n", addr, symtab);
memset(symtab, 0, sizeof(*symtab));

if (addr < 4096)
@@ -149,7 +149,7 @@ int kdbnearsym(unsigned long addr, kdb_s
symtab->mod_name = "kernel";
if (KDB_DEBUG(AR))
kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, "
- "symtab->mod_name=%p, symtab->sym_name=%p (%s)\n", ret,
+ "symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", ret,
symtab->sym_start, symtab->mod_name, symtab->sym_name,
symtab->sym_name);

@@ -887,13 +887,13 @@ void debug_kusage(void)
__func__, dah_first);
if (dah_first) {
h_used = (struct debug_alloc_header *)debug_alloc_pool;
- kdb_printf("%s: h_used %p size %d\n", __func__, h_used,
+ kdb_printf("%s: h_used %px size %d\n", __func__, h_used,
h_used->size);
}
do {
h_used = (struct debug_alloc_header *)
((char *)h_free + dah_overhead + h_free->size);
- kdb_printf("%s: h_used %p size %d caller %p\n",
+ kdb_printf("%s: h_used %px size %d caller %px\n",
__func__, h_used, h_used->size, h_used->caller);
h_free = (struct debug_alloc_header *)
(debug_alloc_pool + h_free->next);
@@ -902,7 +902,7 @@ void debug_kusage(void)
((char *)h_free + dah_overhead + h_free->size);
if ((char *)h_used - debug_alloc_pool !=
sizeof(debug_alloc_pool_aligned))
- kdb_printf("%s: h_used %p size %d caller %p\n",
+ kdb_printf("%s: h_used %px size %d caller %px\n",
__func__, h_used, h_used->size, h_used->caller);
out:
spin_unlock(&dap_lock);