diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 197ad59ab9bf..69b3cac4749d 100644 --- a/Documentation/ramoops.txt +++ b/Documentation/ramoops.txt @@ -102,9 +102,7 @@ related hangs. The functions call chain log is stored in a "ftrace-ramoops" file. Here is an example of usage: # mount -t debugfs debugfs /sys/kernel/debug/ - # cd /sys/kernel/debug/tracing - # echo function > current_tracer - # echo 1 > options/func_pstore + # echo 1 > /sys/kernel/debug/pstore/record_ftrace # reboot -f [...] # mount -t pstore pstore /mnt/ diff --git a/MAINTAINERS b/MAINTAINERS index 42c2264a154c..4b58d5415929 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5550,6 +5550,18 @@ L: cbe-oss-dev@lists.ozlabs.org S: Maintained F: drivers/block/ps3vram.c +PSTORE FILESYSTEM +M: Anton Vorontsov +M: Colin Cross +M: Kees Cook +M: Tony Luck +S: Maintained +T: git git://git.infradead.org/users/cbou/linux-pstore.git +F: fs/pstore/ +F: include/linux/pstore* +F: drivers/firmware/efivars.c +F: drivers/acpi/apei/erst.c + PTP HARDWARE CLOCK SUPPORT M: Richard Cochran S: Maintained diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index d39bb5cce883..ca71db69da07 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -23,6 +23,7 @@ config PSTORE_FTRACE bool "Persistent function tracer" depends on PSTORE depends on FUNCTION_TRACER + depends on DEBUG_FS help With this option kernel traces function calls into a persistent ram buffer that can be decoded and dumped after reboot through diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index a130d484b7d3..2d57e1ac0115 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -17,19 +17,113 @@ #include #include #include +#include +#include +#include +#include +#include +#include +#include #include #include "internal.h" -void notrace pstore_ftrace_call(unsigned long ip, unsigned long parent_ip) +static void notrace pstore_ftrace_call(unsigned long ip, + unsigned long parent_ip) { + unsigned long flags; struct pstore_ftrace_record rec = {}; if (unlikely(oops_in_progress)) return; + local_irq_save(flags); + rec.ip = ip; rec.parent_ip = parent_ip; pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id()); psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec, sizeof(rec), psinfo); + + local_irq_restore(flags); +} + +static struct ftrace_ops pstore_ftrace_ops __read_mostly = { + .func = pstore_ftrace_call, +}; + +static DEFINE_MUTEX(pstore_ftrace_lock); +static bool pstore_ftrace_enabled; + +static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, + size_t count, loff_t *ppos) +{ + u8 on; + ssize_t ret; + + ret = kstrtou8_from_user(buf, count, 2, &on); + if (ret) + return ret; + + mutex_lock(&pstore_ftrace_lock); + + if (!on ^ pstore_ftrace_enabled) + goto out; + + if (on) + ret = register_ftrace_function(&pstore_ftrace_ops); + else + ret = unregister_ftrace_function(&pstore_ftrace_ops); + if (ret) { + pr_err("%s: unable to %sregister ftrace ops: %zd\n", + __func__, on ? "" : "un", ret); + goto err; + } + + pstore_ftrace_enabled = on; +out: + ret = count; +err: + mutex_unlock(&pstore_ftrace_lock); + + return ret; +} + +static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf, + size_t count, loff_t *ppos) +{ + char val[] = { '0' + pstore_ftrace_enabled, '\n' }; + + return simple_read_from_buffer(buf, count, ppos, val, sizeof(val)); +} + +static const struct file_operations pstore_knob_fops = { + .open = simple_open, + .read = pstore_ftrace_knob_read, + .write = pstore_ftrace_knob_write, +}; + +void pstore_register_ftrace(void) +{ + struct dentry *dir; + struct dentry *file; + + if (!psinfo->write_buf) + return; + + dir = debugfs_create_dir("pstore", NULL); + if (!dir) { + pr_err("%s: unable to create pstore directory\n", __func__); + return; + } + + file = debugfs_create_file("record_ftrace", 0600, dir, NULL, + &pstore_knob_fops); + if (!file) { + pr_err("%s: unable to create record_ftrace file\n", __func__); + goto err_file; + } + + return; +err_file: + debugfs_remove(dir); } diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h index 0d0d3b7d5f12..4847f588b7d5 100644 --- a/fs/pstore/internal.h +++ b/fs/pstore/internal.h @@ -39,6 +39,12 @@ pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec) #endif } +#ifdef CONFIG_PSTORE_FTRACE +extern void pstore_register_ftrace(void); +#else +static inline void pstore_register_ftrace(void) {} +#endif + extern struct pstore_info *psinfo; extern void pstore_set_kmsg_bytes(int); diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 29996e8793a7..a40da07e93d6 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -164,7 +164,13 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) if (c > psinfo->bufsize) c = psinfo->bufsize; - spin_lock_irqsave(&psinfo->buf_lock, flags); + + if (oops_in_progress) { + if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) + break; + } else { + spin_lock_irqsave(&psinfo->buf_lock, flags); + } memcpy(psinfo->buf, s, c); psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo); spin_unlock_irqrestore(&psinfo->buf_lock, flags); @@ -236,6 +242,7 @@ int pstore_register(struct pstore_info *psi) kmsg_dump_register(&pstore_dumper); pstore_register_console(); + pstore_register_ftrace(); if (pstore_update_ms >= 0) { pstore_timer.expires = jiffies + diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 0b311bc18916..1a4f6da58eab 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #define RAMOOPS_KERNMSG_HDR "====" @@ -181,12 +182,11 @@ static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz) return len; } - -static int ramoops_pstore_write_buf(enum pstore_type_id type, - enum kmsg_dump_reason reason, - u64 *id, unsigned int part, - const char *buf, size_t size, - struct pstore_info *psi) +static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, + enum kmsg_dump_reason reason, + u64 *id, unsigned int part, + const char *buf, size_t size, + struct pstore_info *psi) { struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz = cxt->przs[cxt->dump_write_cnt]; @@ -406,7 +406,7 @@ static int __devinit ramoops_probe(struct platform_device *pdev) goto fail_init_fprz; if (!cxt->przs && !cxt->cprz && !cxt->fprz) { - pr_err("memory size too small, minimum is %lu\n", + pr_err("memory size too small, minimum is %zu\n", cxt->console_size + cxt->record_size + cxt->ftrace_size); goto fail_cnt; @@ -414,13 +414,14 @@ static int __devinit ramoops_probe(struct platform_device *pdev) cxt->pstore.data = cxt; /* - * Console can handle any buffer size, so prefer dumps buffer - * size since usually it is smaller. + * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we + * have to handle dumps, we must have at least record_size buffer. And + * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be + * ZERO_SIZE_PTR). */ - if (cxt->przs) - cxt->pstore.bufsize = cxt->przs[0]->buffer_size; - else - cxt->pstore.bufsize = cxt->cprz->buffer_size; + if (cxt->console_size) + cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ + cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); spin_lock_init(&cxt->pstore.buf_lock); if (!cxt->pstore.buf) { @@ -537,6 +538,7 @@ postcore_initcall(ramoops_init); static void __exit ramoops_exit(void) { platform_driver_unregister(&ramoops_driver); + platform_device_unregister(dummy); kfree(dummy_data); } module_exit(ramoops_exit); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index c892587d9b81..ee3034a40884 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -64,14 +64,6 @@ struct pstore_info { void *data; }; - -#ifdef CONFIG_PSTORE_FTRACE -extern void pstore_ftrace_call(unsigned long ip, unsigned long parent_ip); -#else -static inline void pstore_ftrace_call(unsigned long ip, unsigned long parent_ip) -{ } -#endif - #ifdef CONFIG_PSTORE extern int pstore_register(struct pstore_info *); #else diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 483162a9f908..507a7a9630bf 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include "trace.h" @@ -76,10 +75,9 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, preempt_enable_notrace(); } -/* Our two options */ +/* Our option */ enum { TRACE_FUNC_OPT_STACK = 0x1, - TRACE_FUNC_OPT_PSTORE = 0x2, }; static struct tracer_flags func_flags; @@ -109,12 +107,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { - /* - * So far tracing doesn't support multiple buffers, so - * we make an explicit call for now. - */ - if (unlikely(func_flags.val & TRACE_FUNC_OPT_PSTORE)) - pstore_ftrace_call(ip, parent_ip); pc = preempt_count(); trace_function(tr, ip, parent_ip, flags, pc); } @@ -180,9 +172,6 @@ static struct ftrace_ops trace_stack_ops __read_mostly = static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, -#endif -#ifdef CONFIG_PSTORE_FTRACE - { TRACER_OPT(func_pstore, TRACE_FUNC_OPT_PSTORE) }, #endif { } /* Always set a last empty entry */ }; @@ -235,8 +224,6 @@ static int func_set_flag(u32 old_flags, u32 bit, int set) register_ftrace_function(&trace_ops); } - break; - case TRACE_FUNC_OPT_PSTORE: break; default: return -EINVAL;