linux_dsm_epyc7002/include/linux/thread_info.h

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/* thread_info.h: common low-level thread information accessors
*
* Copyright (C) 2002 David Howells (dhowells@redhat.com)
* - Incorporating suggestions made by Linus Torvalds
*/
#ifndef _LINUX_THREAD_INFO_H
#define _LINUX_THREAD_INFO_H
futex: fix for futex_wait signal stack corruption David Holmes found a bug in the -rt tree with respect to pthread_cond_timedwait. After trying his test program on the latest git from mainline, I found the bug was there too. The bug he was seeing that his test program showed, was that if one were to do a "Ctrl-Z" on a process that was in the pthread_cond_timedwait, and then did a "bg" on that process, it would return with a "-ETIMEDOUT" but early. That is, the timer would go off early. Looking into this, I found the source of the problem. And it is a rather nasty bug at that. Here's the relevant code from kernel/futex.c: (not in order in the file) [...] smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec __user *utime, u32 __user *uaddr2, u32 val3) { struct timespec ts; ktime_t t, *tp = NULL; u32 val2 = 0; int cmd = op & FUTEX_CMD_MASK; if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (copy_from_user(&ts, utime, sizeof(ts)) != 0) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } [...] return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } [...] long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { int ret; int cmd = op & FUTEX_CMD_MASK; struct rw_semaphore *fshared = NULL; if (!(op & FUTEX_PRIVATE_FLAG)) fshared = &current->mm->mmap_sem; switch (cmd) { case FUTEX_WAIT: ret = futex_wait(uaddr, fshared, val, timeout); [...] static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, u32 val, ktime_t *abs_time) { [...] struct restart_block *restart; restart = &current_thread_info()->restart_block; restart->fn = futex_wait_restart; restart->arg0 = (unsigned long)uaddr; restart->arg1 = (unsigned long)val; restart->arg2 = (unsigned long)abs_time; restart->arg3 = 0; if (fshared) restart->arg3 |= ARG3_SHARED; return -ERESTART_RESTARTBLOCK; [...] static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = (u32 __user *)restart->arg0; u32 val = (u32)restart->arg1; ktime_t *abs_time = (ktime_t *)restart->arg2; struct rw_semaphore *fshared = NULL; restart->fn = do_no_restart_syscall; if (restart->arg3 & ARG3_SHARED) fshared = &current->mm->mmap_sem; return (long)futex_wait(uaddr, fshared, val, abs_time); } So when the futex_wait is interrupt by a signal we break out of the hrtimer code and set up or return from signal. This code does not return back to userspace, so we set up a RESTARTBLOCK. The bug here is that we save the "abs_time" which is a pointer to the stack variable "ktime_t t" from sys_futex. This returns and unwinds the stack before we get to call our signal. On return from the signal we go to futex_wait_restart, where we update all the parameters for futex_wait and call it. But here we have a problem where abs_time is no longer valid. I verified this with print statements, and sure enough, what abs_time was set to ends up being garbage when we get to futex_wait_restart. The solution I did to solve this (with input from Linus Torvalds) was to add unions to the restart_block to allow system calls to use the restart with specific parameters. This way the futex code now saves the time in a 64bit value in the restart block instead of storing it on the stack. Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64 in thread_info.h, when there's a #ifdef __KERNEL__ just below that. Not sure what that is there for. If this turns out to be a problem, I've tested this with using "unsigned int" for u32 and "unsigned long long" for u64 and it worked just the same. I'm using u32 and u64 just to be consistent with what the futex code uses. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 21:46:09 +07:00
#include <linux/types.h>
struct timespec;
struct compat_timespec;
/*
futex: fix for futex_wait signal stack corruption David Holmes found a bug in the -rt tree with respect to pthread_cond_timedwait. After trying his test program on the latest git from mainline, I found the bug was there too. The bug he was seeing that his test program showed, was that if one were to do a "Ctrl-Z" on a process that was in the pthread_cond_timedwait, and then did a "bg" on that process, it would return with a "-ETIMEDOUT" but early. That is, the timer would go off early. Looking into this, I found the source of the problem. And it is a rather nasty bug at that. Here's the relevant code from kernel/futex.c: (not in order in the file) [...] smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec __user *utime, u32 __user *uaddr2, u32 val3) { struct timespec ts; ktime_t t, *tp = NULL; u32 val2 = 0; int cmd = op & FUTEX_CMD_MASK; if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (copy_from_user(&ts, utime, sizeof(ts)) != 0) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } [...] return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } [...] long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { int ret; int cmd = op & FUTEX_CMD_MASK; struct rw_semaphore *fshared = NULL; if (!(op & FUTEX_PRIVATE_FLAG)) fshared = &current->mm->mmap_sem; switch (cmd) { case FUTEX_WAIT: ret = futex_wait(uaddr, fshared, val, timeout); [...] static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, u32 val, ktime_t *abs_time) { [...] struct restart_block *restart; restart = &current_thread_info()->restart_block; restart->fn = futex_wait_restart; restart->arg0 = (unsigned long)uaddr; restart->arg1 = (unsigned long)val; restart->arg2 = (unsigned long)abs_time; restart->arg3 = 0; if (fshared) restart->arg3 |= ARG3_SHARED; return -ERESTART_RESTARTBLOCK; [...] static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = (u32 __user *)restart->arg0; u32 val = (u32)restart->arg1; ktime_t *abs_time = (ktime_t *)restart->arg2; struct rw_semaphore *fshared = NULL; restart->fn = do_no_restart_syscall; if (restart->arg3 & ARG3_SHARED) fshared = &current->mm->mmap_sem; return (long)futex_wait(uaddr, fshared, val, abs_time); } So when the futex_wait is interrupt by a signal we break out of the hrtimer code and set up or return from signal. This code does not return back to userspace, so we set up a RESTARTBLOCK. The bug here is that we save the "abs_time" which is a pointer to the stack variable "ktime_t t" from sys_futex. This returns and unwinds the stack before we get to call our signal. On return from the signal we go to futex_wait_restart, where we update all the parameters for futex_wait and call it. But here we have a problem where abs_time is no longer valid. I verified this with print statements, and sure enough, what abs_time was set to ends up being garbage when we get to futex_wait_restart. The solution I did to solve this (with input from Linus Torvalds) was to add unions to the restart_block to allow system calls to use the restart with specific parameters. This way the futex code now saves the time in a 64bit value in the restart block instead of storing it on the stack. Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64 in thread_info.h, when there's a #ifdef __KERNEL__ just below that. Not sure what that is there for. If this turns out to be a problem, I've tested this with using "unsigned int" for u32 and "unsigned long long" for u64 and it worked just the same. I'm using u32 and u64 just to be consistent with what the futex code uses. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 21:46:09 +07:00
* System call restart block.
*/
struct restart_block {
long (*fn)(struct restart_block *);
futex: fix for futex_wait signal stack corruption David Holmes found a bug in the -rt tree with respect to pthread_cond_timedwait. After trying his test program on the latest git from mainline, I found the bug was there too. The bug he was seeing that his test program showed, was that if one were to do a "Ctrl-Z" on a process that was in the pthread_cond_timedwait, and then did a "bg" on that process, it would return with a "-ETIMEDOUT" but early. That is, the timer would go off early. Looking into this, I found the source of the problem. And it is a rather nasty bug at that. Here's the relevant code from kernel/futex.c: (not in order in the file) [...] smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec __user *utime, u32 __user *uaddr2, u32 val3) { struct timespec ts; ktime_t t, *tp = NULL; u32 val2 = 0; int cmd = op & FUTEX_CMD_MASK; if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (copy_from_user(&ts, utime, sizeof(ts)) != 0) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } [...] return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } [...] long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { int ret; int cmd = op & FUTEX_CMD_MASK; struct rw_semaphore *fshared = NULL; if (!(op & FUTEX_PRIVATE_FLAG)) fshared = &current->mm->mmap_sem; switch (cmd) { case FUTEX_WAIT: ret = futex_wait(uaddr, fshared, val, timeout); [...] static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, u32 val, ktime_t *abs_time) { [...] struct restart_block *restart; restart = &current_thread_info()->restart_block; restart->fn = futex_wait_restart; restart->arg0 = (unsigned long)uaddr; restart->arg1 = (unsigned long)val; restart->arg2 = (unsigned long)abs_time; restart->arg3 = 0; if (fshared) restart->arg3 |= ARG3_SHARED; return -ERESTART_RESTARTBLOCK; [...] static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = (u32 __user *)restart->arg0; u32 val = (u32)restart->arg1; ktime_t *abs_time = (ktime_t *)restart->arg2; struct rw_semaphore *fshared = NULL; restart->fn = do_no_restart_syscall; if (restart->arg3 & ARG3_SHARED) fshared = &current->mm->mmap_sem; return (long)futex_wait(uaddr, fshared, val, abs_time); } So when the futex_wait is interrupt by a signal we break out of the hrtimer code and set up or return from signal. This code does not return back to userspace, so we set up a RESTARTBLOCK. The bug here is that we save the "abs_time" which is a pointer to the stack variable "ktime_t t" from sys_futex. This returns and unwinds the stack before we get to call our signal. On return from the signal we go to futex_wait_restart, where we update all the parameters for futex_wait and call it. But here we have a problem where abs_time is no longer valid. I verified this with print statements, and sure enough, what abs_time was set to ends up being garbage when we get to futex_wait_restart. The solution I did to solve this (with input from Linus Torvalds) was to add unions to the restart_block to allow system calls to use the restart with specific parameters. This way the futex code now saves the time in a 64bit value in the restart block instead of storing it on the stack. Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64 in thread_info.h, when there's a #ifdef __KERNEL__ just below that. Not sure what that is there for. If this turns out to be a problem, I've tested this with using "unsigned int" for u32 and "unsigned long long" for u64 and it worked just the same. I'm using u32 and u64 just to be consistent with what the futex code uses. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 21:46:09 +07:00
union {
struct {
unsigned long arg0, arg1, arg2, arg3;
};
/* For futex_wait */
struct {
u32 *uaddr;
u32 val;
u32 flags;
u32 bitset;
futex: fix for futex_wait signal stack corruption David Holmes found a bug in the -rt tree with respect to pthread_cond_timedwait. After trying his test program on the latest git from mainline, I found the bug was there too. The bug he was seeing that his test program showed, was that if one were to do a "Ctrl-Z" on a process that was in the pthread_cond_timedwait, and then did a "bg" on that process, it would return with a "-ETIMEDOUT" but early. That is, the timer would go off early. Looking into this, I found the source of the problem. And it is a rather nasty bug at that. Here's the relevant code from kernel/futex.c: (not in order in the file) [...] smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec __user *utime, u32 __user *uaddr2, u32 val3) { struct timespec ts; ktime_t t, *tp = NULL; u32 val2 = 0; int cmd = op & FUTEX_CMD_MASK; if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (copy_from_user(&ts, utime, sizeof(ts)) != 0) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } [...] return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } [...] long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { int ret; int cmd = op & FUTEX_CMD_MASK; struct rw_semaphore *fshared = NULL; if (!(op & FUTEX_PRIVATE_FLAG)) fshared = &current->mm->mmap_sem; switch (cmd) { case FUTEX_WAIT: ret = futex_wait(uaddr, fshared, val, timeout); [...] static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, u32 val, ktime_t *abs_time) { [...] struct restart_block *restart; restart = &current_thread_info()->restart_block; restart->fn = futex_wait_restart; restart->arg0 = (unsigned long)uaddr; restart->arg1 = (unsigned long)val; restart->arg2 = (unsigned long)abs_time; restart->arg3 = 0; if (fshared) restart->arg3 |= ARG3_SHARED; return -ERESTART_RESTARTBLOCK; [...] static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = (u32 __user *)restart->arg0; u32 val = (u32)restart->arg1; ktime_t *abs_time = (ktime_t *)restart->arg2; struct rw_semaphore *fshared = NULL; restart->fn = do_no_restart_syscall; if (restart->arg3 & ARG3_SHARED) fshared = &current->mm->mmap_sem; return (long)futex_wait(uaddr, fshared, val, abs_time); } So when the futex_wait is interrupt by a signal we break out of the hrtimer code and set up or return from signal. This code does not return back to userspace, so we set up a RESTARTBLOCK. The bug here is that we save the "abs_time" which is a pointer to the stack variable "ktime_t t" from sys_futex. This returns and unwinds the stack before we get to call our signal. On return from the signal we go to futex_wait_restart, where we update all the parameters for futex_wait and call it. But here we have a problem where abs_time is no longer valid. I verified this with print statements, and sure enough, what abs_time was set to ends up being garbage when we get to futex_wait_restart. The solution I did to solve this (with input from Linus Torvalds) was to add unions to the restart_block to allow system calls to use the restart with specific parameters. This way the futex code now saves the time in a 64bit value in the restart block instead of storing it on the stack. Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64 in thread_info.h, when there's a #ifdef __KERNEL__ just below that. Not sure what that is there for. If this turns out to be a problem, I've tested this with using "unsigned int" for u32 and "unsigned long long" for u64 and it worked just the same. I'm using u32 and u64 just to be consistent with what the futex code uses. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 21:46:09 +07:00
u64 time;
} futex;
/* For nanosleep */
struct {
clockid_t index;
struct timespec __user *rmtp;
#ifdef CONFIG_COMPAT
struct compat_timespec __user *compat_rmtp;
#endif
u64 expires;
} nanosleep;
futex: fix for futex_wait signal stack corruption David Holmes found a bug in the -rt tree with respect to pthread_cond_timedwait. After trying his test program on the latest git from mainline, I found the bug was there too. The bug he was seeing that his test program showed, was that if one were to do a "Ctrl-Z" on a process that was in the pthread_cond_timedwait, and then did a "bg" on that process, it would return with a "-ETIMEDOUT" but early. That is, the timer would go off early. Looking into this, I found the source of the problem. And it is a rather nasty bug at that. Here's the relevant code from kernel/futex.c: (not in order in the file) [...] smlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec __user *utime, u32 __user *uaddr2, u32 val3) { struct timespec ts; ktime_t t, *tp = NULL; u32 val2 = 0; int cmd = op & FUTEX_CMD_MASK; if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (copy_from_user(&ts, utime, sizeof(ts)) != 0) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } [...] return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } [...] long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { int ret; int cmd = op & FUTEX_CMD_MASK; struct rw_semaphore *fshared = NULL; if (!(op & FUTEX_PRIVATE_FLAG)) fshared = &current->mm->mmap_sem; switch (cmd) { case FUTEX_WAIT: ret = futex_wait(uaddr, fshared, val, timeout); [...] static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, u32 val, ktime_t *abs_time) { [...] struct restart_block *restart; restart = &current_thread_info()->restart_block; restart->fn = futex_wait_restart; restart->arg0 = (unsigned long)uaddr; restart->arg1 = (unsigned long)val; restart->arg2 = (unsigned long)abs_time; restart->arg3 = 0; if (fshared) restart->arg3 |= ARG3_SHARED; return -ERESTART_RESTARTBLOCK; [...] static long futex_wait_restart(struct restart_block *restart) { u32 __user *uaddr = (u32 __user *)restart->arg0; u32 val = (u32)restart->arg1; ktime_t *abs_time = (ktime_t *)restart->arg2; struct rw_semaphore *fshared = NULL; restart->fn = do_no_restart_syscall; if (restart->arg3 & ARG3_SHARED) fshared = &current->mm->mmap_sem; return (long)futex_wait(uaddr, fshared, val, abs_time); } So when the futex_wait is interrupt by a signal we break out of the hrtimer code and set up or return from signal. This code does not return back to userspace, so we set up a RESTARTBLOCK. The bug here is that we save the "abs_time" which is a pointer to the stack variable "ktime_t t" from sys_futex. This returns and unwinds the stack before we get to call our signal. On return from the signal we go to futex_wait_restart, where we update all the parameters for futex_wait and call it. But here we have a problem where abs_time is no longer valid. I verified this with print statements, and sure enough, what abs_time was set to ends up being garbage when we get to futex_wait_restart. The solution I did to solve this (with input from Linus Torvalds) was to add unions to the restart_block to allow system calls to use the restart with specific parameters. This way the futex code now saves the time in a 64bit value in the restart block instead of storing it on the stack. Note: I'm a bit nervious to add "linux/types.h" and use u32 and u64 in thread_info.h, when there's a #ifdef __KERNEL__ just below that. Not sure what that is there for. If this turns out to be a problem, I've tested this with using "unsigned int" for u32 and "unsigned long long" for u64 and it worked just the same. I'm using u32 and u64 just to be consistent with what the futex code uses. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-05 21:46:09 +07:00
};
};
extern long do_no_restart_syscall(struct restart_block *parm);
#include <linux/bitops.h>
#include <asm/thread_info.h>
#ifdef __KERNEL__
/*
* flag set/clear/test wrappers
* - pass TIF_xxxx constants to these functions
*/
static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
{
set_bit(flag, (unsigned long *)&ti->flags);
}
static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
{
clear_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_and_set_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_bit(flag, (unsigned long *)&ti->flags);
}
#define set_thread_flag(flag) \
set_ti_thread_flag(current_thread_info(), flag)
#define clear_thread_flag(flag) \
clear_ti_thread_flag(current_thread_info(), flag)
#define test_and_set_thread_flag(flag) \
test_and_set_ti_thread_flag(current_thread_info(), flag)
#define test_and_clear_thread_flag(flag) \
test_and_clear_ti_thread_flag(current_thread_info(), flag)
#define test_thread_flag(flag) \
test_ti_thread_flag(current_thread_info(), flag)
#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)
#ifdef TIF_RESTORE_SIGMASK
/**
* set_restore_sigmask() - make sure saved_sigmask processing gets done
*
* This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
* will run before returning to user mode, to process the flag.
*/
static inline void set_restore_sigmask(void)
{
set_thread_flag(TIF_RESTORE_SIGMASK);
}
#endif /* TIF_RESTORE_SIGMASK */
#endif /* __KERNEL__ */
#endif /* _LINUX_THREAD_INFO_H */