From 50513ecaf5f8336e7ff9698f683a46399cde863d Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 29 Aug 2018 01:18:15 +0900 Subject: tracing/kprobes: Check the probe on unloaded module correctly [ Upstream commit 59158ec4aef7d44be51a6f3e7e17fc64c32604eb ] Current kprobe event doesn't checks correctly whether the given event is on unloaded module or not. It just checks the event has ":" in the name. That is not enough because if we define a probe on non-exist symbol on loaded module, it allows to define that (with warning message) To ensure it correctly, this searches the module name on loaded module list and only if there is not, it allows to define it. (this event will be available when the target module is loaded) Link: http://lkml.kernel.org/r/153547309528.26502.8300278470528281328.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_kprobe.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 6b71860f3998..4a8f3780aae5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -71,9 +71,23 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, return strncmp(mod->name, name, len) == 0 && name[len] == ':'; } -static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) { - return !!strchr(trace_kprobe_symbol(tk), ':'); + char *p; + bool ret; + + if (!tk->symbol) + return false; + p = strchr(tk->symbol, ':'); + if (!p) + return true; + *p = '\0'; + mutex_lock(&module_mutex); + ret = !!find_module(tk->symbol); + mutex_unlock(&module_mutex); + *p = ':'; + + return ret; } static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) @@ -520,19 +534,13 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) else ret = register_kprobe(&tk->rp.kp); - if (ret == 0) + if (ret == 0) { tk->tp.flags |= TP_FLAG_REGISTERED; - else { - if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { - pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); - ret = 0; - } else if (ret == -EILSEQ) { - pr_warn("Probing address(0x%p) is not an instruction boundary.\n", - tk->rp.kp.addr); - ret = -EINVAL; - } + } else if (ret == -EILSEQ) { + pr_warn("Probing address(0x%p) is not an instruction boundary.\n", + tk->rp.kp.addr); + ret = -EINVAL; } - return ret; } @@ -595,6 +603,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk) /* Register k*probe */ ret = __register_trace_kprobe(tk); + if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { + pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); + ret = 0; + } + if (ret < 0) unregister_kprobe_event(tk); else -- cgit v1.2.3 From 6514d22a21adf5467607770e0bdc45b4232d205b Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 27 Sep 2018 17:17:49 +0000 Subject: kdb: use correct pointer when 'btc' calls 'btt' commit dded2e159208a9edc21dd5c5f583afa28d378d39 upstream. On a powerpc 8xx, 'btc' fails as follows: Entering kdb (current=0x(ptrval), pid 282) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0x0 when booting the kernel with 'debug_boot_weak_hash', it fails as well Entering kdb (current=0xba99ad80, pid 284) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0xba99ad80 On other platforms, Oopses have been observed too, see https://github.com/linuxppc/linux/issues/139 This is due to btc calling 'btt' with %p pointer as an argument. This patch replaces %p by %px to get the real pointer value as expected by 'btt' Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: Signed-off-by: Christophe Leroy Reviewed-by: Daniel Thompson Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman --- kernel/debug/kdb/kdb_bt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c index 6ad4a9fcbd6f..7921ae4fca8d 100644 --- a/kernel/debug/kdb/kdb_bt.c +++ b/kernel/debug/kdb/kdb_bt.c @@ -179,14 +179,14 @@ kdb_bt(int argc, const char **argv) kdb_printf("no process for cpu %ld\n", cpu); return 0; } - sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); + sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu)); kdb_parse(buf); return 0; } kdb_printf("btc: cpu status: "); kdb_parse("cpu\n"); for_each_online_cpu(cpu) { - sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); + sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu)); kdb_parse(buf); touch_nmi_watchdog(); } -- cgit v1.2.3 From 13c70ef5b3c7b501d239344fe8cb6caf9ff037f7 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 27 Sep 2018 17:17:57 +0000 Subject: kdb: print real address of pointers instead of hashed addresses 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: Signed-off-by: Christophe Leroy Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman --- kernel/debug/kdb/kdb_main.c | 14 +++++++------- kernel/debug/kdb/kdb_support.c | 12 ++++++------ 2 files changed, 13 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 2ddfce8f1e8f..f338d23b112b 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1192,7 +1192,7 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, 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()); @@ -1208,7 +1208,7 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, */ 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()); @@ -2048,7 +2048,7 @@ static int kdb_lsmod(int argc, const char **argv) 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)); @@ -2059,7 +2059,7 @@ static int kdb_lsmod(int argc, const char **argv) 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 { @@ -2341,7 +2341,7 @@ 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), @@ -2354,7 +2354,7 @@ 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)); } } } @@ -2692,7 +2692,7 @@ 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; } } diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c index 990b3cc526c8..987eb73284d2 100644 --- 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_symtab_t *symtab) 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_symtab_t *symtab) 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); -- cgit v1.2.3