sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ARMv6-M/ARMv7-M: Correct a register handling error in signal delivery (Kernel build mode only). Noted by Mike Smith.

Browse Source
This commit is contained in:
Gregory Nutt 2014-02-23 08:25:49 -06:00
parent 59769d44f1
commit c3cbb6546a
6 changed files with 82 additions and 72 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/arm/include/armv6-m/irq.h
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/include/armv6-m/irq.h
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -178,6 +178,9 @@ struct xcptcontext
uint32_t saved_pc;
uint32_t saved_primask;
uint32_t saved_xpsr;
#ifdef CONFIG_NUTTX_KERNEL
uint32_t saved_lr;
#endif
# ifdef CONFIG_NUTTX_KERNEL
/* This is the saved address to use when returning from a user-space

5
arch/arm/include/armv7-m/irq.h
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/include/armv7-m/irq.h
*
* Copyright (C) 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Copyright (C) 2009, 2011-2012, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -140,6 +140,9 @@ struct xcptcontext
uint32_t saved_primask;
#endif
uint32_t saved_xpsr;
#ifdef CONFIG_NUTTX_KERNEL
uint32_t saved_lr;
#endif
# ifdef CONFIG_NUTTX_KERNEL
/* This is the saved address to use when returning from a user-space

64
arch/arm/src/armv6-m/up_schedulesigaction.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/src/armv6-m/up_schedulesigaction.c
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -116,16 +116,16 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
flags = irqsave();
/* First, handle some special cases when the signal is
* being delivered to the currently executing task.
/* First, handle some special cases when the signal is being delivered
* to the currently executing task.
*/
sdbg("rtcb=0x%p current_regs=0x%p\n", g_readytorun.head, current_regs);
if (tcb == (struct tcb_s*)g_readytorun.head)
{
/* CASE 1: We are not in an interrupt handler and
* a task is signalling itself for some reason.
/* CASE 1: We are not in an interrupt handler and a task is
* signalling itself for some reason.
*/
if (!current_regs)
@ -135,30 +135,26 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
sigdeliver(tcb);
}
/* CASE 2: We are in an interrupt handler AND the
* interrupted task is the same as the one that
* must receive the signal, then we will have to modify
* the return state as well as the state in the TCB.
*
* Hmmm... there looks like a latent bug here: The following
* logic would fail in the strange case where we are in an
* interrupt handler, the thread is signalling itself, but
* a context switch to another task has occurred so that
* current_regs does not refer to the thread at g_readytorun.head!
/* CASE 2: We are in an interrupt handler AND the interrupted
* task is the same as the one that must receive the signal, then
* we will have to modify the return state as well as the state in
* the TCB.
*/
else
{
/* Save the return lr and cpsr and one scratch register
* These will be restored by the signal trampoline after
* the signals have been delivered.
/* Save the return PC, CPSR, and PRIMASK registers (and
* perhaps the LR). These will be restored by the signal
* trampoline after the signal has been delivered.
*/
tcb->xcp.sigdeliver = sigdeliver;
tcb->xcp.saved_pc = current_regs[REG_PC];
tcb->xcp.saved_primask = current_regs[REG_PRIMASK];
tcb->xcp.saved_xpsr = current_regs[REG_XPSR];
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.saved_lr = current_regs[REG_LR];
#endif
/* Then set up to vector to the trampoline with interrupts
* disabled. The kernel-space trampoline must run in
* privileged thread mode.
@ -168,43 +164,47 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
current_regs[REG_PRIMASK] = 1;
current_regs[REG_XPSR] = ARMV6M_XPSR_T;
#ifdef CONFIG_NUTTX_KERNEL
current_regs[REG_XPSR] = EXC_RETURN_PRIVTHR;
current_regs[REG_LR] = EXC_RETURN_PRIVTHR;
#endif
/* And make sure that the saved context in the TCB
* is the same as the interrupt return context.
/* And make sure that the saved context in the TCB is the same
* as the interrupt return context.
*/
up_savestate(tcb->xcp.regs);
}
}
/* Otherwise, we are (1) signaling a task is not running
* from an interrupt handler or (2) we are not in an
* interrupt handler and the running task is signalling
* some non-running task.
/* Otherwise, we are (1) signalling a task is not running from an
* interrupt handler or (2) we are not in an interrupt handler and the
* running task is signalling some non-running task.
*/
else
{
/* Save the return lr and cpsr and one scratch register
* These will be restored by the signal trampoline after
* the signals have been delivered.
/* Save the return PS, CPSR and PRIMASK register (a perhaps also
* the LR). These will be restored by the signal trampoline after
* the signal has been delivered.
*/
tcb->xcp.sigdeliver = sigdeliver;
tcb->xcp.saved_pc = tcb->xcp.regs[REG_PC];
tcb->xcp.saved_primask = tcb->xcp.regs[REG_PRIMASK];
tcb->xcp.saved_xpsr = tcb->xcp.regs[REG_XPSR];
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.saved_lr = tcb->xcp.regs[REG_LR];
#endif
/* Then set up to vector to the trampoline with interrupts
* disabled. We must already be in privileged thread mode
* to be here.
* disabled. We must already be in privileged thread mode to be
* here.
*/
tcb->xcp.regs[REG_PC] = (uint32_t)up_sigdeliver;
tcb->xcp.regs[REG_PRIMASK] = 1;
tcb->xcp.regs[REG_XPSR] = ARMV6M_XPSR_T;
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.regs[REG_LR] = EXC_RETURN_PRIVTHR;
#endif
}
irqrestore(flags);

6
arch/arm/src/armv6-m/up_sigdeliver.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/src/armv6-m/up_sigdeliver.c
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -109,6 +109,9 @@ void up_sigdeliver(void)
regs[REG_PC] = rtcb->xcp.saved_pc;
regs[REG_PRIMASK] = rtcb->xcp.saved_primask;
regs[REG_XPSR] = rtcb->xcp.saved_xpsr;
#ifdef CONFIG_NUTTX_KERNEL
regs[REG_LR] = rtcb->xcp.saved_lr;
#endif
/* Get a local copy of the sigdeliver function pointer. We do this so that
* we can nullify the sigdeliver function pointer in the TCB and accept
@ -144,4 +147,3 @@ void up_sigdeliver(void)
}
#endif /* !CONFIG_DISABLE_SIGNALS */

68
arch/arm/src/armv7-m/up_schedulesigaction.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/src/armv7-m/up_schedulesigaction.c
*
* Copyright (C) 2009-2013 Gregory Nutt. All rights reserved.
* Copyright (C) 2009-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -76,7 +76,7 @@
* This function is called by the OS when one or more
* signal handling actions have been queued for execution.
* The architecture specific code must configure things so
* that the 'igdeliver' callback is executed on the thread
* that the 'sigdeliver' callback is executed on the thread
* specified by 'tcb' as soon as possible.
*
* This function may be called from interrupt handling logic.
@ -116,16 +116,16 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
flags = irqsave();
/* First, handle some special cases when the signal is
* being delivered to the currently executing task.
/* First, handle some special cases when the signal is being delivered
* to the currently executing task.
*/
sdbg("rtcb=0x%p current_regs=0x%p\n", g_readytorun.head, current_regs);
if (tcb == (struct tcb_s*)g_readytorun.head)
{
/* CASE 1: We are not in an interrupt handler and
* a task is signalling itself for some reason.
/* CASE 1: We are not in an interrupt handler and a task is
* signalling itself for some reason.
*/
if (!current_regs)
@ -135,23 +135,18 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
sigdeliver(tcb);
}
/* CASE 2: We are in an interrupt handler AND the
* interrupted task is the same as the one that
* must receive the signal, then we will have to modify
* the return state as well as the state in the TCB.
*
* Hmmm... there looks like a latent bug here: The following
* logic would fail in the strange case where we are in an
* interrupt handler, the thread is signalling itself, but
* a context switch to another task has occurred so that
* current_regs does not refer to the thread at g_readytorun.head!
/* CASE 2: We are in an interrupt handler AND the interrupted
* task is the same as the one that must receive the signal, then
* we will have to modify the return state as well as the state in
* the TCB.
*/
else
{
/* Save the return lr and cpsr and one scratch register
* These will be restored by the signal trampoline after
* the signals have been delivered.
/* Save the return PC, CPSR and either the BASEPRI or PRIMASK
* registers (and perhaps also the LR). These will be
* restored by the signal trampoline after the signal has been
* delivered.
*/
tcb->xcp.sigdeliver = sigdeliver;
@ -162,7 +157,9 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
tcb->xcp.saved_primask = current_regs[REG_PRIMASK];
#endif
tcb->xcp.saved_xpsr = current_regs[REG_XPSR];
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.saved_lr = current_regs[REG_LR];
#endif
/* Then set up to vector to the trampoline with interrupts
* disabled. The kernel-space trampoline must run in
* privileged thread mode.
@ -176,28 +173,26 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
#endif
current_regs[REG_XPSR] = ARMV7M_XPSR_T;
#ifdef CONFIG_NUTTX_KERNEL
current_regs[REG_XPSR] = EXC_RETURN_PRIVTHR;
current_regs[REG_LR] = EXC_RETURN_PRIVTHR;
#endif
/* And make sure that the saved context in the TCB
* is the same as the interrupt return context.
/* And make sure that the saved context in the TCB is the same
* as the interrupt return context.
*/
up_savestate(tcb->xcp.regs);
}
}
/* Otherwise, we are (1) signaling a task is not running
* from an interrupt handler or (2) we are not in an
* interrupt handler and the running task is signalling
* some non-running task.
/* Otherwise, we are (1) signalling a task is not running from an
* interrupt handler or (2) we are not in an interrupt handler and the
* running task is signalling* some non-running task.
*/
else
{
/* Save the return lr and cpsr and one scratch register
* These will be restored by the signal trampoline after
* the signals have been delivered.
/* Save the return PC, CPSR and either the BASEPRI or PRIMASK
* registers (and perhaps also the LR). These will be restored
* by the signal trampoline after the signal has been delivered.
*/
tcb->xcp.sigdeliver = sigdeliver;
@ -208,10 +203,12 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
tcb->xcp.saved_primask = tcb->xcp.regs[REG_PRIMASK];
#endif
tcb->xcp.saved_xpsr = tcb->xcp.regs[REG_XPSR];
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.saved_lr = tcb->xcp.regs[REG_LR];
#endif
/* Then set up to vector to the trampoline with interrupts
* disabled. We must already be in privileged thread mode
* to be here.
* disabled. We must already be in privileged thread mode to be
* here.
*/
tcb->xcp.regs[REG_PC] = (uint32_t)up_sigdeliver;
@ -221,6 +218,9 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
tcb->xcp.regs[REG_PRIMASK] = 1;
#endif
tcb->xcp.regs[REG_XPSR] = ARMV7M_XPSR_T;
#ifdef CONFIG_NUTTX_KERNEL
tcb->xcp.regs[REG_LR] = EXC_RETURN_PRIVTHR;
#endif
}
irqrestore(flags);

6
arch/arm/src/armv7-m/up_sigdeliver.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/src/armv7-m/up_sigdeliver.c
*
* Copyright (C) 2009-2010, 2013 Gregory Nutt. All rights reserved.
* Copyright (C) 2009-2010, 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -108,6 +108,9 @@ void up_sigdeliver(void)
regs[REG_PRIMASK] = rtcb->xcp.saved_primask;
#endif
regs[REG_XPSR] = rtcb->xcp.saved_xpsr;
#ifdef CONFIG_NUTTX_KERNEL
regs[REG_LR] = rtcb->xcp.saved_lr;
#endif
/* Get a local copy of the sigdeliver function pointer. We do this so that
* we can nullify the sigdeliver function pointer in the TCB and accept
@ -147,4 +150,3 @@ void up_sigdeliver(void)
}
#endif /* !CONFIG_DISABLE_SIGNALS */