X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fbackend.h;h=d811911020d10f0b9d32e9cfaa3ce18a4ad0ae70;hb=30cddf693eea0129b25c9761db6b202ddef549b3;hp=da937f29d6f8cc3c8954ca4be7361e9f7e003139;hpb=80bb26003945e96a8ade9c8788dab9b2e08cbc08;p=lttng-modules.git

diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h
index da937f29..d8119110 100644
--- a/lib/ringbuffer/backend.h
+++ b/lib/ringbuffer/backend.h
@@ -156,7 +156,7 @@ 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 = READ_ONCE(src[count]);
+		c = LTTNG_READ_ONCE(src[count]);
 		if (!c)
 			break;
 		lib_ring_buffer_do_copy(config, &dest[count], &c, 1);
@@ -277,7 +277,6 @@ void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config
 	size_t offset = ctx->buf_offset;
 	struct lib_ring_buffer_backend_pages *backend_pages;
 	unsigned long ret;
-	mm_segment_t old_fs = get_fs();
 
 	if (unlikely(!len))
 		return;
@@ -287,7 +286,6 @@ 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;
@@ -304,19 +302,18 @@ 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->priv.buf_offset += len;
 }
 
 /**
@@ -347,7 +344,6 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf
 	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();
 
 	if (unlikely(!len))
 		return;
@@ -357,7 +353,6 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf
 	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;
@@ -388,14 +383,12 @@ 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.
@@ -403,6 +396,7 @@ 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->priv.buf_offset += len;
 }
 
 /*
@@ -447,16 +441,12 @@ 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;
 }