X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fbackend.h;h=46dcf1ccd9053443c4d00a743f5e1d19b2aa9ddb;hb=6423140ffcb1c5b005199bb2fa34621361ad538d;hp=b362a04a436bfe64c640f694968032fb7de5aa32;hpb=d723e9056812fdee222f1156f45f7a43393c5863;p=lttng-modules.git diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h index b362a04a..46dcf1cc 100644 --- a/lib/ringbuffer/backend.h +++ b/lib/ringbuffer/backend.h @@ -1,31 +1,18 @@ -#ifndef _LIB_RING_BUFFER_BACKEND_H -#define _LIB_RING_BUFFER_BACKEND_H - -/* +/* SPDX-License-Identifier: (GPL-2.0 OR LGPL-2.1) + * * lib/ringbuffer/backend.h * * Ring buffer backend (API). * * Copyright (C) 2010-2012 Mathieu Desnoyers * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; only - * version 2.1 of the License. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * * Credits to Steven Rostedt for proposing to use an extra-subbuffer owned by * the reader in flight recorder mode. */ +#ifndef _LIB_RING_BUFFER_BACKEND_H +#define _LIB_RING_BUFFER_BACKEND_H + #include #include #include @@ -34,7 +21,8 @@ #include #include #include -#include +#include +#include /* Internal helpers */ #include @@ -90,26 +78,20 @@ void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, { struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index, pagecpy; + size_t index, pagecpy; size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; + struct lib_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; + backend_pages = + lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(ctx->chan, - config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); if (likely(pagecpy == len)) lib_ring_buffer_do_copy(config, - rpages->p[index].virt + backend_pages->p[index].virt + (offset & ~PAGE_MASK), src, len); else @@ -137,25 +119,19 @@ void lib_ring_buffer_memset(const struct lib_ring_buffer_config *config, struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index, pagecpy; + size_t index, pagecpy; size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; + struct lib_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; + backend_pages = + lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(ctx->chan, - config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); if (likely(pagecpy == len)) - lib_ring_buffer_do_memset(rpages->p[index].virt + lib_ring_buffer_do_memset(backend_pages->p[index].virt + (offset & ~PAGE_MASK), c, len); else @@ -181,7 +157,7 @@ size_t lib_ring_buffer_do_strcpy(const struct lib_ring_buffer_config *config, * Only read source character once, in case it is * modified concurrently. */ - c = ACCESS_ONCE(src[count]); + c = LTTNG_READ_ONCE(src[count]); if (!c) break; lib_ring_buffer_do_copy(config, &dest[count], &c, 1); @@ -240,28 +216,22 @@ void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, { struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index, pagecpy; + size_t index, pagecpy; size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; + struct lib_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; + backend_pages = + lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(ctx->chan, - config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); if (likely(pagecpy == len)) { size_t count; count = lib_ring_buffer_do_strcpy(config, - rpages->p[index].virt + backend_pages->p[index].virt + (offset & ~PAGE_MASK), src, len - 1); offset += count; @@ -269,13 +239,13 @@ void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, if (unlikely(count < len - 1)) { size_t pad_len = len - 1 - count; - lib_ring_buffer_do_memset(rpages->p[index].virt + lib_ring_buffer_do_memset(backend_pages->p[index].virt + (offset & ~PAGE_MASK), pad, pad_len); offset += pad_len; } /* Ending '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt + lib_ring_buffer_do_memset(backend_pages->p[index].virt + (offset & ~PAGE_MASK), '\0', 1); } else { @@ -304,34 +274,26 @@ void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config { struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index, pagecpy; + size_t index, pagecpy; size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; + struct lib_ring_buffer_backend_pages *backend_pages; unsigned long ret; - mm_segment_t old_fs = get_fs(); if (unlikely(!len)) return; + backend_pages = + lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(ctx->chan, - config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - - set_fs(KERNEL_DS); + pagefault_disable(); - if (unlikely(!access_ok(VERIFY_READ, src, len))) + if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) goto fill_buffer; if (likely(pagecpy == len)) { ret = lib_ring_buffer_do_copy_from_user_inatomic( - rpages->p[index].virt + (offset & ~PAGE_MASK), + backend_pages->p[index].virt + (offset & ~PAGE_MASK), src, len); if (unlikely(ret > 0)) { /* Copy failed. */ @@ -341,19 +303,18 @@ void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config _lib_ring_buffer_copy_from_user_inatomic(bufb, offset, src, len, 0); } pagefault_enable(); - set_fs(old_fs); ctx->buf_offset += len; return; fill_buffer: pagefault_enable(); - set_fs(old_fs); /* * In the error path we call the slow path version to avoid * the pollution of static inline code. */ _lib_ring_buffer_memset(bufb, offset, 0, len, 0); + ctx->buf_offset += len; } /** @@ -381,35 +342,27 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf { struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; struct channel_backend *chanb = &ctx->chan->backend; - size_t sbidx, index, pagecpy; + size_t index, pagecpy; size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - mm_segment_t old_fs = get_fs(); + struct lib_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; + backend_pages = + lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(ctx->chan, - config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - - set_fs(KERNEL_DS); + pagefault_disable(); - if (unlikely(!access_ok(VERIFY_READ, src, len))) + if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) goto fill_buffer; if (likely(pagecpy == len)) { size_t count; count = lib_ring_buffer_do_strcpy_from_user_inatomic(config, - rpages->p[index].virt + backend_pages->p[index].virt + (offset & ~PAGE_MASK), src, len - 1); offset += count; @@ -417,13 +370,13 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf if (unlikely(count < len - 1)) { size_t pad_len = len - 1 - count; - lib_ring_buffer_do_memset(rpages->p[index].virt + lib_ring_buffer_do_memset(backend_pages->p[index].virt + (offset & ~PAGE_MASK), pad, pad_len); offset += pad_len; } /* Ending '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt + lib_ring_buffer_do_memset(backend_pages->p[index].virt + (offset & ~PAGE_MASK), '\0', 1); } else { @@ -431,14 +384,12 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf len, 0, pad); } pagefault_enable(); - set_fs(old_fs); ctx->buf_offset += len; return; fill_buffer: pagefault_enable(); - set_fs(old_fs); /* * In the error path we call the slow path version to avoid * the pollution of static inline code. @@ -446,6 +397,7 @@ fill_buffer: _lib_ring_buffer_memset(bufb, offset, pad, len - 1, 0); offset += len - 1; _lib_ring_buffer_memset(bufb, offset, '\0', 1, 0); + ctx->buf_offset += len; } /* @@ -489,18 +441,7 @@ unsigned long lib_ring_buffer_copy_from_user_check_nofault(void *dest, const void __user *src, unsigned long len) { - unsigned long ret; - mm_segment_t old_fs; - - if (!access_ok(VERIFY_READ, src, len)) - return 1; - old_fs = get_fs(); - set_fs(KERNEL_DS); - pagefault_disable(); - ret = __copy_from_user_inatomic(dest, src, len); - pagefault_enable(); - set_fs(old_fs); - return ret; + return lttng_copy_from_user_check_nofault(dest, src, len); } #endif /* _LIB_RING_BUFFER_BACKEND_H */