diff options
| -rw-r--r-- | kernel/printk/printk.c | 30 | ||||
| -rw-r--r-- | kernel/printk/printk_ringbuffer.c | 145 | ||||
| -rw-r--r-- | kernel/printk/printk_ringbuffer.h | 29 |
3 files changed, 133 insertions, 71 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 9a2e23191576..25cfe4fe48af 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -959,11 +959,11 @@ void log_buf_vmcoreinfo_setup(void) VMCOREINFO_STRUCT_SIZE(prb_desc_ring); VMCOREINFO_OFFSET(prb_desc_ring, count_bits); VMCOREINFO_OFFSET(prb_desc_ring, descs); + VMCOREINFO_OFFSET(prb_desc_ring, infos); VMCOREINFO_OFFSET(prb_desc_ring, head_id); VMCOREINFO_OFFSET(prb_desc_ring, tail_id); VMCOREINFO_STRUCT_SIZE(prb_desc); - VMCOREINFO_OFFSET(prb_desc, info); VMCOREINFO_OFFSET(prb_desc, state_var); VMCOREINFO_OFFSET(prb_desc, text_blk_lpos); VMCOREINFO_OFFSET(prb_desc, dict_blk_lpos); @@ -1097,11 +1097,13 @@ static char setup_dict_buf[CONSOLE_EXT_LOG_MAX] __initdata; void __init setup_log_buf(int early) { + struct printk_info *new_infos; unsigned int new_descs_count; struct prb_desc *new_descs; struct printk_info info; struct printk_record r; size_t new_descs_size; + size_t new_infos_size; unsigned long flags; char *new_dict_buf; char *new_log_buf; @@ -1142,8 +1144,7 @@ void __init setup_log_buf(int early) if (unlikely(!new_dict_buf)) { pr_err("log_buf_len: %lu dict bytes not available\n", new_log_buf_len); - memblock_free(__pa(new_log_buf), new_log_buf_len); - return; + goto err_free_log_buf; } new_descs_size = new_descs_count * sizeof(struct prb_desc); @@ -1151,9 +1152,15 @@ void __init setup_log_buf(int early) if (unlikely(!new_descs)) { pr_err("log_buf_len: %zu desc bytes not available\n", new_descs_size); - memblock_free(__pa(new_dict_buf), new_log_buf_len); - memblock_free(__pa(new_log_buf), new_log_buf_len); - return; + goto err_free_dict_buf; + } + + new_infos_size = new_descs_count * sizeof(struct printk_info); + new_infos = memblock_alloc(new_infos_size, LOG_ALIGN); + if (unlikely(!new_infos)) { + pr_err("log_buf_len: %zu info bytes not available\n", + new_infos_size); + goto err_free_descs; } prb_rec_init_rd(&r, &info, @@ -1163,7 +1170,8 @@ void __init setup_log_buf(int early) prb_init(&printk_rb_dynamic, new_log_buf, ilog2(new_log_buf_len), new_dict_buf, ilog2(new_log_buf_len), - new_descs, ilog2(new_descs_count)); + new_descs, ilog2(new_descs_count), + new_infos); logbuf_lock_irqsave(flags); @@ -1192,6 +1200,14 @@ void __init setup_log_buf(int early) pr_info("log_buf_len: %u bytes\n", log_buf_len); pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); + return; + +err_free_descs: + memblock_free(__pa(new_descs), new_descs_size); +err_free_dict_buf: + memblock_free(__pa(new_dict_buf), new_log_buf_len); +err_free_log_buf: + memblock_free(__pa(new_log_buf), new_log_buf_len); } static bool __read_mostly ignore_loglevel; diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c index f4e2e9890e0f..de4b10a98623 100644 --- a/kernel/printk/printk_ringbuffer.c +++ b/kernel/printk/printk_ringbuffer.c @@ -15,10 +15,10 @@ * The printk_ringbuffer is made up of 3 internal ringbuffers: * * desc_ring - * A ring of descriptors. A descriptor contains all record meta data - * (sequence number, timestamp, loglevel, etc.) as well as internal state - * information about the record and logical positions specifying where in - * the other ringbuffers the text and dictionary strings are located. + * A ring of descriptors and their meta data (such as sequence number, + * timestamp, loglevel, etc.) as well as internal state information about + * the record and logical positions specifying where in the other + * ringbuffers the text and dictionary strings are located. * * text_data_ring * A ring of data blocks. A data block consists of an unsigned long @@ -38,13 +38,14 @@ * * Descriptor Ring * ~~~~~~~~~~~~~~~ - * The descriptor ring is an array of descriptors. A descriptor contains all - * the meta data of a printk record as well as blk_lpos structs pointing to - * associated text and dictionary data blocks (see "Data Rings" below). Each - * descriptor is assigned an ID that maps directly to index values of the - * descriptor array and has a state. The ID and the state are bitwise combined - * into a single descriptor field named @state_var, allowing ID and state to - * be synchronously and atomically updated. + * The descriptor ring is an array of descriptors. A descriptor contains + * essential meta data to track the data of a printk record using + * blk_lpos structs pointing to associated text and dictionary data blocks + * (see "Data Rings" below). Each descriptor is assigned an ID that maps + * directly to index values of the descriptor array and has a state. The ID + * and the state are bitwise combined into a single descriptor field named + * @state_var, allowing ID and state to be synchronously and atomically + * updated. * * Descriptors have four states: * @@ -150,6 +151,14 @@ * descriptor. If a data block is not valid, the @tail_lpos cannot be * advanced beyond it. * + * Info Array + * ~~~~~~~~~~ + * The general meta data of printk records are stored in printk_info structs, + * stored in an array with the same number of elements as the descriptor ring. + * Each info corresponds to the descriptor of the same index in the + * descriptor ring. Info validity is confirmed by evaluating the corresponding + * descriptor before and after loading the info. + * * Usage * ----- * Here are some simple examples demonstrating writers and readers. For the @@ -367,6 +376,15 @@ static struct prb_desc *to_desc(struct prb_desc_ring *desc_ring, u64 n) return &desc_ring->descs[DESC_INDEX(desc_ring, n)]; } +/* + * Return the printk_info associated with @n. @n can be either a + * descriptor ID or a sequence number. + */ +static struct printk_info *to_info(struct prb_desc_ring *desc_ring, u64 n) +{ + return &desc_ring->infos[DESC_INDEX(desc_ring, n)]; +} + static struct prb_data_block *to_block(struct prb_data_ring *data_ring, unsigned long begin_lpos) { @@ -425,10 +443,16 @@ static enum desc_state get_desc_state(unsigned long id, * Get a copy of a specified descriptor and return its queried state. If the * descriptor is in an inconsistent state (miss or reserved), the caller can * only expect the descriptor's @state_var field to be valid. + * + * The sequence number and caller_id can be optionally retrieved. Like all + * non-state_var data, they are only valid if the descriptor is in a + * consistent state. */ static enum desc_state desc_read(struct prb_desc_ring *desc_ring, - unsigned long id, struct prb_desc *desc_out) + unsigned long id, struct prb_desc *desc_out, + u64 *seq_out, u32 *caller_id_out) { + struct printk_info *info = to_info(desc_ring, id); struct prb_desc *desc = to_desc(desc_ring, id); atomic_long_t *state_var = &desc->state_var; enum desc_state d_state; @@ -469,11 +493,14 @@ static enum desc_state desc_read(struct prb_desc_ring *desc_ring, * state has been re-checked. A memcpy() for all of @desc * cannot be used because of the atomic_t @state_var field. */ - memcpy(&desc_out->info, &desc->info, sizeof(desc_out->info)); /* LMM(desc_read:C) */ memcpy(&desc_out->text_blk_lpos, &desc->text_blk_lpos, - sizeof(desc_out->text_blk_lpos)); /* also part of desc_read:C */ + sizeof(desc_out->text_blk_lpos)); /* LMM(desc_read:C) */ memcpy(&desc_out->dict_blk_lpos, &desc->dict_blk_lpos, sizeof(desc_out->dict_blk_lpos)); /* also part of desc_read:C */ + if (seq_out) + *seq_out = info->seq; /* also part of desc_read:C */ + if (caller_id_out) + *caller_id_out = info->caller_id; /* also part of desc_read:C */ /* * 1. Guarantee the descriptor content is loaded before re-checking @@ -588,7 +615,8 @@ static bool data_make_reusable(struct printk_ringbuffer *rb, */ id = blk->id; /* LMM(data_make_reusable:A) */ - d_state = desc_read(desc_ring, id, &desc); /* LMM(data_make_reusable:B) */ + d_state = desc_read(desc_ring, id, &desc, + NULL, NULL); /* LMM(data_make_reusable:B) */ switch (d_state) { case desc_miss: @@ -771,7 +799,7 @@ static bool desc_push_tail(struct printk_ringbuffer *rb, enum desc_state d_state; struct prb_desc desc; - d_state = desc_read(desc_ring, tail_id, &desc); + d_state = desc_read(desc_ring, tail_id, &desc, NULL, NULL); switch (d_state) { case desc_miss: @@ -823,7 +851,8 @@ static bool desc_push_tail(struct printk_ringbuffer *rb, * equal to @head_id so there is no risk of pushing the tail past the * head. */ - d_state = desc_read(desc_ring, DESC_ID(tail_id + 1), &desc); /* LMM(desc_push_tail:A) */ + d_state = desc_read(desc_ring, DESC_ID(tail_id + 1), &desc, + NULL, NULL); /* LMM(desc_push_tail:A) */ if (d_state == desc_finalized || d_state == desc_reusable) { /* @@ -1264,6 +1293,7 @@ static struct prb_desc *desc_reopen_last(struct prb_desc_ring *desc_ring, struct prb_desc desc; struct prb_desc *d; unsigned long id; + u32 cid; id = atomic_long_read(&desc_ring->head_id); @@ -1271,8 +1301,8 @@ static struct prb_desc *desc_reopen_last(struct prb_desc_ring *desc_ring, * To reduce unnecessarily reopening, first check if the descriptor * state and caller ID are correct. */ - d_state = desc_read(desc_ring, id, &desc); - if (d_state != desc_committed || desc.info.caller_id != caller_id) + d_state = desc_read(desc_ring, id, &desc, NULL, &cid); + if (d_state != desc_committed || cid != caller_id) return NULL; d = to_desc(desc_ring, id); @@ -1353,6 +1383,8 @@ static struct prb_desc *desc_reopen_last(struct prb_desc_ring *desc_ring, bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, struct printk_record *r, u32 caller_id) { + struct prb_desc_ring *desc_ring = &rb->desc_ring; + struct printk_info *info; unsigned int data_size; struct prb_desc *d; unsigned long id; @@ -1360,7 +1392,7 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer local_irq_save(e->irqflags); /* Transition the newest descriptor back to the reserved state. */ - d = desc_reopen_last(&rb->desc_ring, caller_id, &id); + d = desc_reopen_last(desc_ring, caller_id, &id); if (!d) { local_irq_restore(e->irqflags); goto fail_reopen; @@ -1368,6 +1400,8 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer /* Now the writer has exclusive access: LMM(prb_reserve_in_last:A) */ + info = to_info(desc_ring, id); + /* * Set the @e fields here so that prb_commit() can be used if * anything fails from now on. @@ -1380,14 +1414,14 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer * exclusive access at that point. The descriptor may have * changed since then. */ - if (caller_id != d->info.caller_id) + if (caller_id != info->caller_id) goto fail; if (BLK_DATALESS(&d->text_blk_lpos)) { - if (WARN_ON_ONCE(d->info.text_len != 0)) { + if (WARN_ON_ONCE(info->text_len != 0)) { pr_warn_once("wrong text_len value (%hu, expecting 0)\n", - d->info.text_len); - d->info.text_len = 0; + info->text_len); + info->text_len = 0; } if (!data_check_size(&rb->text_data_ring, r->text_buf_size)) @@ -1404,12 +1438,12 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer * the meta data (@text_len) is not sane, use the full data * block size. */ - if (WARN_ON_ONCE(d->info.text_len > data_size)) { + if (WARN_ON_ONCE(info->text_len > data_size)) { pr_warn_once("wrong text_len value (%hu, expecting <=%u)\n", - d->info.text_len, data_size); - d->info.text_len = data_size; + info->text_len, data_size); + info->text_len = data_size; } - r->text_buf_size += d->info.text_len; + r->text_buf_size += info->text_len; if (!data_check_size(&rb->text_data_ring, r->text_buf_size)) goto fail; @@ -1424,7 +1458,7 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer r->dict_buf = NULL; r->dict_buf_size = 0; - r->info = &d->info; + r->info = info; e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos); @@ -1486,6 +1520,7 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, struct printk_record *r) { struct prb_desc_ring *desc_ring = &rb->desc_ring; + struct printk_info *info; struct prb_desc *d; unsigned long id; u64 seq; @@ -1512,14 +1547,15 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, } d = to_desc(desc_ring, id); + info = to_info(desc_ring, id); /* * All @info fields (except @seq) are cleared and must be filled in * by the writer. Save @seq before clearing because it is used to * determine the new sequence number. */ - seq = d->info.seq; - memset(&d->info, 0, sizeof(d->info)); + seq = info->seq; + memset(info, 0, sizeof(*info)); /* * Set the @e fields here so that prb_commit() can be used if @@ -1533,16 +1569,16 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, * Otherwise just increment it by a full wrap. * * @seq is considered "never been set" if it has a value of 0, - * _except_ for @descs[0], which was specially setup by the ringbuffer + * _except_ for @infos[0], which was specially setup by the ringbuffer * initializer and therefore is always considered as set. * * See the "Bootstrap" comment block in printk_ringbuffer.h for * details about how the initializer bootstraps the descriptors. */ if (seq == 0 && DESC_INDEX(desc_ring, id) != 0) - d->info.seq = DESC_INDEX(desc_ring, id); + info->seq = DESC_INDEX(desc_ring, id); else - d->info.seq = seq + DESCS_COUNT(desc_ring); + info->seq = seq + DESCS_COUNT(desc_ring); /* * New data is about to be reserved. Once that happens, previous @@ -1550,7 +1586,7 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, * previous descriptor now so that it can be made available to * readers. (For seq==0 there is no previous descriptor.) */ - if (d->info.seq > 0) + if (info->seq > 0) desc_make_final(desc_ring, DESC_ID(id - 1)); r->text_buf = data_alloc(rb, &rb->text_data_ring, r->text_buf_size, @@ -1571,7 +1607,7 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb, if (r->dict_buf_size && !r->dict_buf) r->dict_buf_size = 0; - r->info = &d->info; + r->info = info; /* Record full text space used by record. */ e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos); @@ -1726,12 +1762,12 @@ static bool copy_data(struct prb_data_ring *data_ring, /* * Actual cannot be less than expected. It can be more than expected * because of the trailing alignment padding. + * + * Note that invalid @len values can occur because the caller loads + * the value during an allowed data race. */ - if (WARN_ON_ONCE(data_size < (unsigned int)len)) { - pr_warn_once("wrong data size (%u, expecting >=%hu) for data: %.*s\n", - data_size, len, data_size, data); + if (data_size < (unsigned int)len) return false; - } /* Caller interested in the line count? */ if (line_count) @@ -1764,8 +1800,9 @@ static int desc_read_finalized_seq(struct prb_desc_ring *desc_ring, { struct prb_data_blk_lpos *blk_lpos = &desc_out->text_blk_lpos; enum desc_state d_state; + u64 s; - d_state = desc_read(desc_ring, id, desc_out); + d_state = desc_read(desc_ring, id, desc_out, &s, NULL); /* * An unexpected @id (desc_miss) or @seq mismatch means the record @@ -1775,7 +1812,7 @@ static int desc_read_finalized_seq(struct prb_desc_ring *desc_ring, if (d_state == desc_miss || d_state == desc_reserved || d_state == desc_committed || - desc_out->info.seq != seq) { + s != seq) { return -EINVAL; } @@ -1802,6 +1839,7 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq, struct printk_record *r, unsigned int *line_count) { struct prb_desc_ring *desc_ring = &rb->desc_ring; + struct printk_info *info = to_info(desc_ring, seq); struct prb_desc *rdesc = to_desc(desc_ring, seq); atomic_long_t *state_var = &rdesc->state_var; struct prb_desc desc; @@ -1823,10 +1861,10 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq, /* If requested, copy meta data. */ if (r->info) - memcpy(r->info, &desc.info, sizeof(*(r->info))); + memcpy(r->info, info, sizeof(*(r->info))); /* Copy text data. If it fails, this is a data-less record. */ - if (!copy_data(&rb->text_data_ring, &desc.text_blk_lpos, desc.info.text_len, + if (!copy_data(&rb->text_data_ring, &desc.text_blk_lpos, info->text_len, r->text_buf, r->text_buf_size, line_count)) { return -ENOENT; } @@ -1836,7 +1874,7 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq, * important. So if it fails, modify the copied meta data to report * that there is no dict data, thus silently dropping the dict data. */ - if (!copy_data(&rb->dict_data_ring, &desc.dict_blk_lpos, desc.info.dict_len, + if (!copy_data(&rb->dict_data_ring, &desc.dict_blk_lpos, info->dict_len, r->dict_buf, r->dict_buf_size, NULL)) { if (r->info) r->info->dict_len = 0; @@ -1853,11 +1891,12 @@ static u64 prb_first_seq(struct printk_ringbuffer *rb) enum desc_state d_state; struct prb_desc desc; unsigned long id; + u64 seq; for (;;) { id = atomic_long_read(&rb->desc_ring.tail_id); /* LMM(prb_first_seq:A) */ - d_state = desc_read(desc_ring, id, &desc); /* LMM(prb_first_seq:B) */ + d_state = desc_read(desc_ring, id, &desc, &seq, NULL); /* LMM(prb_first_seq:B) */ /* * This loop will not be infinite because the tail is @@ -1886,7 +1925,7 @@ static u64 prb_first_seq(struct printk_ringbuffer *rb) smp_rmb(); /* LMM(prb_first_seq:C) */ } - return desc.info.seq; + return seq; } /* @@ -2049,6 +2088,7 @@ u64 prb_next_seq(struct printk_ringbuffer *rb) * @dictbits: The size of @dict_buf as a power-of-2 value. * @descs: The descriptor buffer for ringbuffer records. * @descbits: The count of @descs items as a power-of-2 value. + * @infos: The printk_info buffer for ringbuffer records. * * This is the public function available to writers to setup a ringbuffer * during runtime using provided buffers. @@ -2060,12 +2100,15 @@ u64 prb_next_seq(struct printk_ringbuffer *rb) void prb_init(struct printk_ringbuffer *rb, char *text_buf, unsigned int textbits, char *dict_buf, unsigned int dictbits, - struct prb_desc *descs, unsigned int descbits) + struct prb_desc *descs, unsigned int descbits, + struct printk_info *infos) { memset(descs, 0, _DESCS_COUNT(descbits) * sizeof(descs[0])); + memset(infos, 0, _DESCS_COUNT(descbits) * sizeof(infos[0])); rb->desc_ring.count_bits = descbits; rb->desc_ring.descs = descs; + rb->desc_ring.infos = infos; atomic_long_set(&rb->desc_ring.head_id, DESC0_ID(descbits)); atomic_long_set(&rb->desc_ring.tail_id, DESC0_ID(descbits)); @@ -2081,14 +2124,14 @@ void prb_init(struct printk_ringbuffer *rb, atomic_long_set(&rb->fail, 0); - descs[0].info.seq = -(u64)_DESCS_COUNT(descbits); - - descs[_DESCS_COUNT(descbits) - 1].info.seq = 0; atomic_long_set(&(descs[_DESCS_COUNT(descbits) - 1].state_var), DESC0_SV(descbits)); descs[_DESCS_COUNT(descbits) - 1].text_blk_lpos.begin = FAILED_LPOS; descs[_DESCS_COUNT(descbits) - 1].text_blk_lpos.next = FAILED_LPOS; descs[_DESCS_COUNT(descbits) - 1].dict_blk_lpos.begin = FAILED_LPOS; descs[_DESCS_COUNT(descbits) - 1].dict_blk_lpos.next = FAILED_LPOS; + + infos[0].seq = -(u64)_DESCS_COUNT(descbits); + infos[_DESCS_COUNT(descbits) - 1].seq = 0; } /** diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h index 853ea62dc5f2..97c8561e74e0 100644 --- a/kernel/printk/printk_ringbuffer.h +++ b/kernel/printk/printk_ringbuffer.h @@ -58,7 +58,6 @@ struct prb_data_blk_lpos { * @state_var: A bitwise combination of descriptor ID and descriptor state. */ struct prb_desc { - struct printk_info info; atomic_long_t state_var; struct prb_data_blk_lpos text_blk_lpos; struct prb_data_blk_lpos dict_blk_lpos; @@ -76,6 +75,7 @@ struct prb_data_ring { struct prb_desc_ring { unsigned int count_bits; struct prb_desc *descs; + struct printk_info *infos; atomic_long_t head_id; atomic_long_t tail_id; }; @@ -237,19 +237,8 @@ enum desc_state { static char _##name##_dict[1U << ((avgdictbits) + (descbits))] \ __aligned(__alignof__(unsigned long)); \ static struct prb_desc _##name##_descs[_DESCS_COUNT(descbits)] = { \ - /* this will be the first record reserved by a writer */ \ - [0] = { \ - .info = { \ - /* will be incremented to 0 on the first reservation */ \ - .seq = -(u64)_DESCS_COUNT(descbits), \ - }, \ - }, \ /* the initial head and tail */ \ [_DESCS_COUNT(descbits) - 1] = { \ - .info = { \ - /* reports the first seq value during the bootstrap phase */ \ - .seq = 0, \ - }, \ /* reusable */ \ .state_var = ATOMIC_INIT(DESC0_SV(descbits)), \ /* no associated data block */ \ @@ -257,10 +246,23 @@ static struct prb_desc _##name##_descs[_DESCS_COUNT(descbits)] = { \ .dict_blk_lpos = FAILED_BLK_LPOS, \ }, \ }; \ +static struct printk_info _##name##_infos[_DESCS_COUNT(descbits)] = { \ + /* this will be the first record reserved by a writer */ \ + [0] = { \ + /* will be incremented to 0 on the first reservation */ \ + .seq = -(u64)_DESCS_COUNT(descbits), \ + }, \ + /* the initial head and tail */ \ + [_DESCS_COUNT(descbits) - 1] = { \ + /* reports the first seq value during the bootstrap phase */ \ + .seq = 0, \ + }, \ +}; \ static struct printk_ringbuffer name = { \ .desc_ring = { \ .count_bits = descbits, \ .descs = &_##name##_descs[0], \ + .infos = &_##name##_infos[0], \ .head_id = ATOMIC_INIT(DESC0_ID(descbits)), \ .tail_id = ATOMIC_INIT(DESC0_ID(descbits)), \ }, \ @@ -336,7 +338,8 @@ void prb_final_commit(struct prb_reserved_entry *e); void prb_init(struct printk_ringbuffer *rb, char *text_buf, unsigned int text_buf_size, char *dict_buf, unsigned int dict_buf_size, - struct prb_desc *descs, unsigned int descs_count_bits); + struct prb_desc *descs, unsigned int descs_count_bits, + struct printk_info *infos); unsigned int prb_record_text_space(struct prb_reserved_entry *e); /* Reader Interface */ |