9ffc66941d
extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Kees Cook <kees@outflux.net> iQIcBAABCgAGBQJX/BAFAAoJEIly9N/cbcAmzW8QALFbCs7EFFkML+M/M/9d8zEk 1QbUs/z8covJTTT1PjSdw7JUrAMulI3S00owpcQVd/PcWjRPU80QwfsXBgIB0tvC Kub2qxn6Oaf+kTB646zwjFgjdCecw/USJP+90nfcu2+LCnE8ReclKd1aUee+Bnhm iDEUyH2ONIoWq6ta2Z9sA7+E4y2ZgOlmW0iga3Mnf+OcPtLE70fWPoe5E4g9DpYk B+kiPDrD9ql5zsHaEnKG1ldjiAZ1L6Grk8rGgLEXmbOWtTOFmnUhR+raK5NA/RCw MXNuyPay5aYPpqDHFm+OuaWQAiPWfPNWM3Ett4k0d9ZWLixTcD1z68AciExwk7aW SEA8b1Jwbg05ZNYM7NJB6t6suKC4dGPxWzKFOhmBicsh2Ni5f+Az0BQL6q8/V8/4 8UEqDLuFlPJBB50A3z5ngCVeYJKZe8Bg/Swb4zXl6mIzZ9darLzXDEV6ystfPXxJ e1AdBb41WC+O2SAI4l64yyeswkGo3Iw2oMbXG5jmFl6wY/xGp7dWxw7gfnhC6oOh afOT54p2OUDfSAbJaO0IHliWoIdmE5ZYdVYVU9Ek+uWyaIwcXhNmqRg+Uqmo32jf cP5J9x2kF3RdOcbSHXmFp++fU+wkhBtEcjkNpvkjpi4xyA47IWS7lrVBBebrCq9R pa/A7CNQwibIV6YD8+/p =1dUK -----END PGP SIGNATURE----- Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin
124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
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* descriptor table internals; you almost certainly want file.h instead.
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*/
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#ifndef __LINUX_FDTABLE_H
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#define __LINUX_FDTABLE_H
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#include <linux/posix_types.h>
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#include <linux/compiler.h>
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/atomic.h>
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/*
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* The default fd array needs to be at least BITS_PER_LONG,
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* as this is the granularity returned by copy_fdset().
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*/
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#define NR_OPEN_DEFAULT BITS_PER_LONG
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struct fdtable {
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unsigned int max_fds;
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struct file __rcu **fd; /* current fd array */
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unsigned long *close_on_exec;
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unsigned long *open_fds;
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unsigned long *full_fds_bits;
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struct rcu_head rcu;
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};
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static inline bool close_on_exec(unsigned int fd, const struct fdtable *fdt)
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{
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return test_bit(fd, fdt->close_on_exec);
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}
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static inline bool fd_is_open(unsigned int fd, const struct fdtable *fdt)
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{
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return test_bit(fd, fdt->open_fds);
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}
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/*
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* Open file table structure
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*/
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struct files_struct {
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/*
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* read mostly part
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*/
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atomic_t count;
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bool resize_in_progress;
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wait_queue_head_t resize_wait;
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struct fdtable __rcu *fdt;
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struct fdtable fdtab;
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/*
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* written part on a separate cache line in SMP
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*/
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spinlock_t file_lock ____cacheline_aligned_in_smp;
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unsigned int next_fd;
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unsigned long close_on_exec_init[1];
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unsigned long open_fds_init[1];
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unsigned long full_fds_bits_init[1];
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struct file __rcu * fd_array[NR_OPEN_DEFAULT];
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};
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struct file_operations;
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struct vfsmount;
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struct dentry;
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#define rcu_dereference_check_fdtable(files, fdtfd) \
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rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock))
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#define files_fdtable(files) \
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rcu_dereference_check_fdtable((files), (files)->fdt)
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/*
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* The caller must ensure that fd table isn't shared or hold rcu or file lock
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*/
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static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd)
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{
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struct fdtable *fdt = rcu_dereference_raw(files->fdt);
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if (fd < fdt->max_fds)
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return rcu_dereference_raw(fdt->fd[fd]);
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return NULL;
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}
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static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd)
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{
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RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&
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!lockdep_is_held(&files->file_lock),
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"suspicious rcu_dereference_check() usage");
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return __fcheck_files(files, fd);
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}
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/*
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* Check whether the specified fd has an open file.
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*/
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#define fcheck(fd) fcheck_files(current->files, fd)
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struct task_struct;
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struct files_struct *get_files_struct(struct task_struct *);
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void put_files_struct(struct files_struct *fs);
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void reset_files_struct(struct files_struct *);
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int unshare_files(struct files_struct **);
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struct files_struct *dup_fd(struct files_struct *, int *) __latent_entropy;
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void do_close_on_exec(struct files_struct *);
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int iterate_fd(struct files_struct *, unsigned,
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int (*)(const void *, struct file *, unsigned),
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const void *);
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extern int __alloc_fd(struct files_struct *files,
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unsigned start, unsigned end, unsigned flags);
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extern void __fd_install(struct files_struct *files,
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unsigned int fd, struct file *file);
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extern int __close_fd(struct files_struct *files,
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unsigned int fd);
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extern struct kmem_cache *files_cachep;
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#endif /* __LINUX_FDTABLE_H */
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