_2025-03-30_14：11：55_2025-03-30 14：11：55
RISC-V SSTC扩展对Linux CRNG影响分析 - DeepSeek - 探索未至之境
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TAGs:处理器 risc-v timer SSTC random
Summary: The user is asking for an analysis of the impact of RISC-V's SSTC extension on Linux's CRNG (Cryptographic Random Number Generator) and the getrandom system call. The SSTC extension may refer to "Supervisor Software Time Compare" or some time-related extension, but it's not clear without checking the search results. However, the user's question seems to involve RISC-V's security vulnerabilities or random number generation mechanisms. For instance, one page mentions that RISC-V enabled the general CPU vulnerability reporting feature in Linux 6.12 kernel, including the detection and mitigation status. This might be related to system security, which in turn affects the reliability of the random number generator. CRNG is a random number generation module in the Linux kernel, while getrandom is a system call for obtaining random numbers in user space. If RISC-V's SSTC extension introduces new instructions or hardware features, it may affect the efficiency or security of random number generation. For example, one page discusses RISC-V Linux entry address memory optimization, which might involve kernel startup time memory management but is not directly related to random number generation. Another page mentions RISC-V processor vulnerabilities, such as GhostWrite, which can impact system security and, consequently, CRNG's data source. If SSTC extension improves time stamping or counters, it may provide higher-quality interrupt sources or entropy sources for CRNG, thereby improving random number generation speed and quality. One page discusses RISC-V's development in the software ecosystem, including toolchain and compiler optimization, which may indirectly affect the implementation of random number generation in the kernel. For instance, new extensions may require kernel module adaptation and optimization of the entropy collection process. Additionally, pages 7 and 8 discuss RISC-V's integration with the open-source community, which might involve kernel developers supporting RISC-V's new features. If SSTC extension requires kernel-level modifications, such as in driver or architecture-related code, this may impact CRNG's implementation. In summary, while the search results do not directly mention SSTC extension, it can be inferred that SSTC may be a security or time-related extension, and its impact may include improving entropy source collection efficiency, enhancing random number generation security, or requiring kernel adaptation. For example, if SSTC provides hardware random number generation instructions, the kernel's CRNG may utilize these instructions to improve performance and reduce reliance on software entropy sources. Furthermore, vulnerability patches, such as the one mentioned in page 2, can strengthen CRNG's security by addressing hardware vulnerabilities that could lead to random number prediction risks. RISC-V's SSTC (Supervisor Software Time Compare) extension is a part of RISC-V's privileged architecture, primarily used for optimizing time management and interrupt handling. Its impact on Linux's CRNG and getrandom can be summarized as follows:
_2025-03-29_23：58：36_2025-03-29 23：58：36
Linux内核函数wait_for_random_bytes详解 - DeepSeek - 探索未至之境
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TAGs:操作系统 linux random
Summary: The Linux kernel function `wait_for_random_bytes` is used to ensure that the random number generator (RNG) in the Linux kernel is ready and has sufficient entropy before continuing execution in situations where secure random numbers are required, such as encryption operations or key generation. The function blocks the current thread until the RNG has completed initialization and has an adequate amount of entropy. It is particularly important during system startup or when the entropy pool has not yet accumulated sufficient random data. By using `wait_for_random_bytes`, developers can prevent the generation of weak random numbers, which could lead to security vulnerabilities. The function works by checking if the RNG is ready using the `crng_ready()` function. If the RNG is not yet initialized, the function blocks the current thread and adds it to the `crng_init_wait` queue, waiting until the RNG is ready to continue execution. The function can be used in various contexts, such as in driver initialization or in generating secure tokens. It is essential to note that the function should only be used in contexts where sleeping is allowed, as it may call functions that cause the system to sleep, such as `wait_event`. Additionally, the function can have performance implications, especially during system startup when the entropy pool may take a long time to initialize. Alternative solutions include using non-blocking functions or actively adding entropy sources to the pool. Related functions include `get_random_bytes`, `add_hwgenerator_randomness`, and `urandom_read`.Linux 内核函数 'wait_for_random_bytes' 用于确保 Linux 内核中的随机数生成器 （RNG） 已准备就绪并具有足够的熵，然后才能在需要安全随机数的情况下继续执行，例如加密作或密钥生成。该函数会阻止当前线程，直到 RNG 完成初始化并具有足够的熵量。在系统启动期间或熵池尚未积累足够的随机数据时，这一点尤为重要。通过使用 'wait_for_random_bytes'，开发人员可以防止产生弱随机数，这可能会导致安全漏洞。该函数通过使用 'crng_ready（）' 函数检查 RNG 是否准备就绪来工作。如果 RNG 尚未初始化，该函数会阻止当前线程并将其添加到 'crng_init_wait' 队列中，等待 RNG 准备好继续执行。该函数可用于各种上下文，例如驱动程序初始化或生成安全令牌。需要注意的是，该函数只应在允许休眠的上下文中使用，因为它可能会调用导致系统休眠的函数，例如 'wait_event'。此外，该函数可能会对性能产生影响，尤其是在系统启动期间，此时熵池可能需要很长时间才能初始化。替代解决方案包括使用非阻塞函数或主动向池中添加熵源。相关函数包括 'get_random_bytes'、'add_hwgenerator_randomness' 和 'urandom_read'。
_2025-03-30_13：19：19_2025-03-30 13：19：19
Linux内核函数wait_for_random_bytes详解 - DeepSeek - 探索未至之境
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TAGs:操作系统 linux random
Summary: The `wait_for_random_bytes` function in the Linux kernel is used to ensure that the random number generator (RNG) is ready and has sufficient entropy before generating secure random numbers. The function blocks the caller until the RNG is initialized and has enough entropy.
_2025-03-30_21：47：41_2025-03-30 21：47：41
Linux内核函数wait_for_random_bytes详解 - DeepSeek - 探索未至之境
原文链接失效了?试试备份
TAGs:操作系统 linux random
Summary: The Linux kernel function `wait_for_random_bytes` is used to ensure that the random number generator (RNG) in the Linux kernel is ready and has sufficient entropy before continuing execution in situations where secure random numbers are required, such as encryption operations or key generation. The function blocks the current thread until the RNG has completed initialization and has an adequate amount of entropy. It is particularly important during system startup or when the entropy pool has not yet accumulated sufficient random data. By using `wait_for_random_bytes`, developers can prevent the generation of weak random numbers, which could lead to security vulnerabilities. The function works by checking if the RNG is ready using the `crng_ready()` function. If the RNG is not yet initialized, the function blocks the current thread and adds it to the `crng_init_wait` queue, waiting until the RNG is ready to continue execution. The function can be used in various contexts, such as in driver initialization or in generating secure tokens. It is essential to note that the function should only be used in contexts where sleeping is allowed, as it may call functions that cause the system to sleep, such as `wait_event`. Additionally, the function can have performance implications, especially during system startup when the entropy pool may take a long time to initialize. Alternative solutions include using non-blocking functions or actively adding entropy sources to the pool. Related functions include `get_random_bytes`, `add_hwgenerator_randomness`, and `urandom_read`.Linux 内核函数 'wait_for_random_bytes' 用于确保 Linux 内核中的随机数生成器 （RNG） 已准备就绪并具有足够的熵，然后才能在需要安全随机数的情况下继续执行，例如加密作或密钥生成。该函数会阻止当前线程，直到 RNG 完成初始化并具有足够的熵量。在系统启动期间或熵池尚未积累足够的随机数据时，这一点尤为重要。通过使用 'wait_for_random_bytes'，开发人员可以防止产生弱随机数，这可能会导致安全漏洞。该函数通过使用 'crng_ready（）' 函数检查 RNG 是否准备就绪来工作。如果 RNG 尚未初始化，该函数会阻止当前线程并将其添加到 'crng_init_wait' 队列中，等待 RNG 准备好继续执行。该函数可用于各种上下文，例如驱动程序初始化或生成安全令牌。需要注意的是，该函数只应在允许休眠的上下文中使用，因为它可能会调用导致系统休眠的函数，例如 'wait_event'。此外，该函数可能会对性能产生影响，尤其是在系统启动期间，此时熵池可能需要很长时间才能初始化。替代解决方案包括使用非阻塞函数或主动向池中添加熵源。相关函数包括 'get_random_bytes'、'add_hwgenerator_randomness' 和 'urandom_read'。
_2025-03-30_13：46：50_2025-03-30 13：46：50
Linux系统启动时的getrandom随机数系统调用阻塞问题
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TAGs:操作系统 linux random
Summary: This text discusses an issue with the getrandom system call in the Linux kernel, which can cause a delay during system startup due to the entropy pool not being fully initialized yet. The entropy pool is used to generate high-quality random numbers for various purposes, but it needs to be initialized before it can provide these numbers to applications. If the pool is not initialized, the getrandom() system call without the GRND\_NONBLOCK flag will block until the initialization is complete. This can cause applications that depend on the kernel's random number generator to also experience a delay during system startup. The text suggests enabling the CONFIG\_RANDOM\_TRUST\_CPU option during kernel compilation to trust the CPU's random number generator to seed the kernel's CRNG and avoid this delay. However, this option is not enabled by default on some distributions. The text also mentions various hardware and software sources of entropy and how they are used by the Linux kernel.本文讨论了 Linux 内核中 getrandom 系统调用的一个问题，由于熵池尚未完全初始化，这可能会导致系统启动期间出现延迟。熵池用于生成用于各种目的的高质量随机数，但需要先初始化，然后才能将这些数字提供给应用程序。如果池未初始化，则没有 GRND\_NONBLOCK 标志的 getrandom（） 系统调用将阻塞，直到初始化完成。这可能会导致依赖内核随机数生成器的应用程序在系统启动期间也遇到延迟。文本建议在内核编译期间启用 CONFIG\_RANDOM\_TRUST\_CPU 选项，以信任 CPU 的随机数生成器为内核的 CRNG 提供种子并避免这种延迟。但是，默认情况下，某些分配上不启用此选项。该文本还提到了各种硬件和软件熵源，以及 Linux 内核如何使用它们。