X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=include%2Fringbuffer%2Fbackend.h;h=13f67a4ea8c51e48f8832ff1813931a772997442;hb=e5f1eb9a2a0f516b32966aad52be990b093f24ad;hp=67592546dec2d08cb757e33ce83af3190ec92833;hpb=585e5dcc4bf017c03b86dc84371f9c6170e12785;p=lttng-modules.git diff --git a/include/ringbuffer/backend.h b/include/ringbuffer/backend.h index 67592546..13f67a4e 100644 --- a/include/ringbuffer/backend.h +++ b/include/ringbuffer/backend.h @@ -31,18 +31,18 @@ /* Ring buffer backend access (read/write) */ -extern size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, +extern size_t lib_ring_buffer_read(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset, void *dest, size_t len); -extern int __lib_ring_buffer_copy_to_user(struct lib_ring_buffer_backend *bufb, +extern int __lib_ring_buffer_copy_to_user(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset, void __user *dest, size_t len); -extern int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, +extern int lib_ring_buffer_read_cstr(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset, void *dest, size_t len); extern unsigned long * -lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, size_t offset, +lib_ring_buffer_read_get_pfn(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset, void ***virt); /* @@ -52,10 +52,10 @@ lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, size_t offset * as long as the write is never bigger than a page size. */ extern void * -lib_ring_buffer_offset_address(struct lib_ring_buffer_backend *bufb, +lib_ring_buffer_offset_address(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset); extern void * -lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, +lib_ring_buffer_read_offset_address(struct lttng_kernel_ring_buffer_backend *bufb, size_t offset); /** @@ -71,15 +71,15 @@ lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, * if copy is crossing a page boundary. */ static inline __attribute__((always_inline)) -void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, +void lib_ring_buffer_write(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, const void *src, size_t len) { - struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; - struct channel_backend *chanb = &ctx->chan->backend; + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; size_t index, pagecpy; - size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *backend_pages; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; @@ -95,7 +95,7 @@ void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, src, len); else _lib_ring_buffer_write(bufb, offset, src, len, 0); - ctx->buf_offset += len; + ctx->priv.buf_offset += len; } /** @@ -112,15 +112,15 @@ void lib_ring_buffer_write(const struct lib_ring_buffer_config *config, * boundary. */ static inline -void lib_ring_buffer_memset(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, int c, size_t len) +void lib_ring_buffer_memset(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, int c, size_t len) { - struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; - struct channel_backend *chanb = &ctx->chan->backend; + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; size_t index, pagecpy; - size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *backend_pages; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; @@ -135,7 +135,7 @@ void lib_ring_buffer_memset(const struct lib_ring_buffer_config *config, c, len); else _lib_ring_buffer_memset(bufb, offset, c, len, 0); - ctx->buf_offset += len; + ctx->priv.buf_offset += len; } /* @@ -144,7 +144,7 @@ void lib_ring_buffer_memset(const struct lib_ring_buffer_config *config, * copied. Does *not* terminate @dest with NULL terminating character. */ static inline __attribute__((always_inline)) -size_t lib_ring_buffer_do_strcpy(const struct lib_ring_buffer_config *config, +size_t lib_ring_buffer_do_strcpy(const struct lttng_kernel_ring_buffer_config *config, char *dest, const char *src, size_t len) { size_t count; @@ -175,7 +175,7 @@ size_t lib_ring_buffer_do_strcpy(const struct lib_ring_buffer_config *config, * previously. */ static inline __attribute__((always_inline)) -size_t lib_ring_buffer_do_strcpy_from_user_inatomic(const struct lib_ring_buffer_config *config, +size_t lib_ring_buffer_do_strcpy_from_user_inatomic(const struct lttng_kernel_ring_buffer_config *config, char *dest, const char __user *src, size_t len) { size_t count; @@ -209,15 +209,15 @@ size_t lib_ring_buffer_do_strcpy_from_user_inatomic(const struct lib_ring_buffer * (_ring_buffer_strcpy) if copy is crossing a page boundary. */ static inline -void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, +void lib_ring_buffer_strcpy(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, const char *src, size_t len, int pad) { - struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; - struct channel_backend *chanb = &ctx->chan->backend; - size_t index, pagecpy; - size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *backend_pages; + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; + size_t index, bytes_left_in_page; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; @@ -225,8 +225,8 @@ void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - if (likely(pagecpy == len)) { + bytes_left_in_page = min_t(size_t, len, (-offset) & ~PAGE_MASK); + if (likely(bytes_left_in_page == len)) { size_t count; count = lib_ring_buffer_do_strcpy(config, @@ -248,9 +248,71 @@ void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, + (offset & ~PAGE_MASK), '\0', 1); } else { - _lib_ring_buffer_strcpy(bufb, offset, src, len, 0, pad); + _lib_ring_buffer_strcpy(bufb, offset, src, len, pad); } - ctx->buf_offset += len; + ctx->priv.buf_offset += len; +} + +/** + * lib_ring_buffer_pstrcpy - write kernel C-string (input) to a buffer backend P-string + * @config : ring buffer instance configuration + * @ctx: ring buffer context. (input arguments only) + * @src : source pointer to copy from + * @len : length of data to copy + * @pad : character to use for padding + * + * This function copies up to @len bytes of data from a source pointer + * to a Pascal String into the buffer backend. If a terminating '\0' + * character is found in @src before @len characters are copied, pad the + * buffer with @pad characters (e.g. '\0'). + * + * The length of the pascal strings in the ring buffer is explicit: it + * is either the array or sequence length. + */ +static inline +void lib_ring_buffer_pstrcpy(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, + const char *src, size_t len, char pad) + __attribute__((always_inline)); +static inline +void lib_ring_buffer_pstrcpy(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, + const char *src, size_t len, char pad) +{ + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; + size_t index, bytes_left_in_page; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_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; + index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; + bytes_left_in_page = min_t(size_t, len, (-offset) & ~PAGE_MASK); + if (likely(bytes_left_in_page == len)) { + size_t count; + + count = lib_ring_buffer_do_strcpy(config, + backend_pages->p[index].virt + + (offset & ~PAGE_MASK), + src, len); + offset += count; + /* Padding */ + if (unlikely(count < len)) { + size_t pad_len = len - count; + + lib_ring_buffer_do_memset(backend_pages->p[index].virt + + (offset & ~PAGE_MASK), + pad, pad_len); + offset += pad_len; + } + } else { + _lib_ring_buffer_pstrcpy(bufb, offset, src, len, pad); + } + ctx->priv.buf_offset += len; } /** @@ -267,17 +329,16 @@ void lib_ring_buffer_strcpy(const struct lib_ring_buffer_config *config, * Disable the page fault handler to ensure we never try to take the mmap_sem. */ static inline __attribute__((always_inline)) -void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, +void lib_ring_buffer_copy_from_user_inatomic(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, const void __user *src, size_t len) { - struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; - struct channel_backend *chanb = &ctx->chan->backend; + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; size_t index, pagecpy; - size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *backend_pages; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_ring_buffer_backend_pages *backend_pages; unsigned long ret; - mm_segment_t old_fs = get_fs(); if (unlikely(!len)) return; @@ -287,36 +348,35 @@ void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); - set_fs(KERNEL_DS); - pagefault_disable(); if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) goto fill_buffer; + pagefault_disable(); if (likely(pagecpy == len)) { ret = lib_ring_buffer_do_copy_from_user_inatomic( backend_pages->p[index].virt + (offset & ~PAGE_MASK), src, len); if (unlikely(ret > 0)) { /* Copy failed. */ - goto fill_buffer; + goto fill_buffer_enable_pf; } } else { _lib_ring_buffer_copy_from_user_inatomic(bufb, offset, src, len, 0); } pagefault_enable(); - set_fs(old_fs); - ctx->buf_offset += len; + ctx->priv.buf_offset += len; return; -fill_buffer: +fill_buffer_enable_pf: pagefault_enable(); - set_fs(old_fs); +fill_buffer: /* * 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->priv.buf_offset += len; } /** @@ -338,16 +398,15 @@ fill_buffer: * take the mmap_sem. */ static inline -void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_ctx *ctx, +void lib_ring_buffer_strcpy_from_user_inatomic(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, const void __user *src, size_t len, int pad) { - struct lib_ring_buffer_backend *bufb = &ctx->buf->backend; - struct channel_backend *chanb = &ctx->chan->backend; - size_t index, pagecpy; - size_t offset = ctx->buf_offset; - struct lib_ring_buffer_backend_pages *backend_pages; - mm_segment_t old_fs = get_fs(); + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; + size_t index, bytes_left_in_page; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_ring_buffer_backend_pages *backend_pages; if (unlikely(!len)) return; @@ -355,14 +414,13 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf lib_ring_buffer_get_backend_pages_from_ctx(config, ctx); offset &= chanb->buf_size - 1; index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - pagecpy = min_t(size_t, len, (-offset) & ~PAGE_MASK); + bytes_left_in_page = min_t(size_t, len, (-offset) & ~PAGE_MASK); - set_fs(KERNEL_DS); - pagefault_disable(); if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) goto fill_buffer; - if (likely(pagecpy == len)) { + pagefault_disable(); + if (likely(bytes_left_in_page == len)) { size_t count; count = lib_ring_buffer_do_strcpy_from_user_inatomic(config, @@ -385,17 +443,14 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf '\0', 1); } else { _lib_ring_buffer_strcpy_from_user_inatomic(bufb, offset, src, - len, 0, pad); + len, pad); } pagefault_enable(); - set_fs(old_fs); - ctx->buf_offset += len; + ctx->priv.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. @@ -403,6 +458,85 @@ 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->priv.buf_offset += len; +} + +/** + * lib_ring_buffer_pstrcpy_from_user_inatomic - write user-space C-string (input) to a buffer backend P-string + * @config : ring buffer instance configuration + * @ctx: ring buffer context. (input arguments only) + * @src : source pointer to copy from + * @len : length of data to copy + * @pad : character to use for padding + * + * This function copies up to @len bytes of data from a source pointer + * to a Pascal String into the buffer backend. If a terminating '\0' + * character is found in @src before @len characters are copied, pad the + * buffer with @pad characters (e.g. '\0'). + * + * The length of the pascal strings in the ring buffer is explicit: it + * is either the array or sequence length. + */ +static inline +void lib_ring_buffer_pstrcpy_from_user_inatomic(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, + const char __user *src, size_t len, char pad) + __attribute__((always_inline)); +static inline +void lib_ring_buffer_pstrcpy_from_user_inatomic(const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer_ctx *ctx, + const char __user *src, size_t len, char pad) +{ + struct lttng_kernel_ring_buffer_backend *bufb = &ctx->priv.buf->backend; + struct channel_backend *chanb = &ctx->priv.chan->backend; + size_t index, bytes_left_in_page; + size_t offset = ctx->priv.buf_offset; + struct lttng_kernel_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; + index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; + bytes_left_in_page = min_t(size_t, len, (-offset) & ~PAGE_MASK); + + if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) + goto fill_buffer; + + pagefault_disable(); + if (likely(bytes_left_in_page == len)) { + size_t count; + + count = lib_ring_buffer_do_strcpy_from_user_inatomic(config, + backend_pages->p[index].virt + + (offset & ~PAGE_MASK), + src, len); + offset += count; + /* Padding */ + if (unlikely(count < len)) { + size_t pad_len = len - count; + + lib_ring_buffer_do_memset(backend_pages->p[index].virt + + (offset & ~PAGE_MASK), + pad, pad_len); + offset += pad_len; + } + } else { + _lib_ring_buffer_pstrcpy_from_user_inatomic(bufb, offset, src, len, pad); + } + ctx->priv.buf_offset += len; + pagefault_enable(); + + return; + +fill_buffer: + /* + * In the error path we call the slow path version to avoid + * the pollution of static inline code. + */ + _lib_ring_buffer_memset(bufb, offset, pad, len, 0); + ctx->priv.buf_offset += len; } /* @@ -412,11 +546,11 @@ fill_buffer: */ static inline unsigned long lib_ring_buffer_get_records_unread( - const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf) + const struct lttng_kernel_ring_buffer_config *config, + struct lttng_kernel_ring_buffer *buf) { - struct lib_ring_buffer_backend *bufb = &buf->backend; - struct lib_ring_buffer_backend_pages *pages; + struct lttng_kernel_ring_buffer_backend *bufb = &buf->backend; + struct lttng_kernel_ring_buffer_backend_pages *pages; unsigned long records_unread = 0, sb_bindex, id; unsigned int i; @@ -447,16 +581,12 @@ unsigned long lib_ring_buffer_copy_from_user_check_nofault(void *dest, unsigned long len) { unsigned long ret; - mm_segment_t old_fs; if (!lttng_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; }