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minix/kernel/system/do_sigreturn.c

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Al's system call -> kernel call renaming
2005-10-14 10:58:59 +02:00
/* The kernel call that is implemented in this file:
System processes can be signaled; signals are transformed in SYS_EVENT message that passes signal map along. This mechanisms is also used for nonuser signals like SIGKMESS, SIGKSTOP, SIGKSIG. Revised comments of many system call handlers. Renamed setpriority to nice.
2005-07-19 14:21:36 +02:00
* m_type: SYS_SIGRETURN
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
*
Al's system call -> kernel call renaming
2005-10-14 10:58:59 +02:00
* The parameters for this kernel call are:
'proc number' is process slot, 'endpoint' are generation-aware process instance numbers, encoded and decoded using macros in <minix/endpoint.h>. proc number -> endpoint migration . proc_nr in the interrupt hook is now an endpoint, proc_nr_e. . m_source for messages and notifies is now an endpoint, instead of proc number. . isokendpt() converts an endpoint to a process number, returns success (but fails if the process number is out of range, the process slot is not a living process, or the given endpoint number does not match the endpoint number in the process slot, indicating an old process). . okendpt() is the same as isokendpt(), but panic()s if the conversion fails. This is mainly used for decoding message.m_source endpoints, and other endpoint numbers in kernel data structures, which should always be correct. . if DEBUG_ENABLE_IPC_WARNINGS is enabled, isokendpt() and okendpt() get passed the __FILE__ and __LINE__ of the calling lines, and print messages about what is wrong with the endpoint number (out of range proc, empty proc, or inconsistent endpoint number), with the caller, making finding where the conversion failed easy without having to include code for every call to print where things went wrong. Sometimes this is harmless (wrong arg to a kernel call), sometimes it's a fatal internal inconsistency (bogus m_source). . some process table fields have been appended an _e to indicate it's become and endpoint. . process endpoint is stored in p_endpoint, without generation number. it turns out the kernel never needs the generation number, except when fork()ing, so it's decoded then. . kernel calls all take endpoints as arguments, not proc numbers. the one exception is sys_fork(), which needs to know in which slot to put the child.
2006-03-03 11:00:02 +01:00
* m2_i1: SIG_ENDPT # process returning from handler
System processes can be signaled; signals are transformed in SYS_EVENT message that passes signal map along. This mechanisms is also used for nonuser signals like SIGKMESS, SIGKSTOP, SIGKSIG. Revised comments of many system call handlers. Renamed setpriority to nice.
2005-07-19 14:21:36 +02:00
* m2_p1: SIG_CTXT_PTR # pointer to sigcontext structure
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
*
*/
Convert kernel over to bsdmake
2010-04-02 00:22:33 +02:00
#include "kernel/system.h"
*** empty log message ***
2005-07-19 17:01:47 +02:00
#include <string.h>
Include directory reorg and makefile updates. -Convert the include directory over to using bsdmake syntax -Update/add mkfiles -Modify install(1) so that it can create symlinks -Update makefiles to use new install(1) options -Rename /usr/include/ibm to /usr/include/i386 -Create /usr/include/machine symlink to arch header files -Move vm_i386.h to its new home in the /usr/include/i386 -Update source files to #include the header files at their new homes. -Add new gnu-includes target for building GCC headers
2010-03-08 12:04:59 +01:00
#include <machine/cpu.h>
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
#if USE_SIGRETURN
/*===========================================================================*
* do_sigreturn *
*===========================================================================*/
retire PUBLIC, PRIVATE and FORWARD
2012-03-25 20:25:53 +02:00
int do_sigreturn(struct proc * caller, message * m_ptr)
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
{
/* POSIX style signals require sys_sigreturn to put things in order before
* the signalled process can resume execution
*/
struct sigcontext sc;
register struct proc *rp;
proc_addr() returns address based on location in proc array - pproc_addr is not neccessary to get the address of a process if we know its number - local proc variables in system calls implementation (sys_task) conflicts with the global proc array of all process, therefore the variable were renamed to proc_nr as they hold the process number
2009-09-15 11:57:22 +02:00
int proc_nr, r;
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
proc_addr() returns address based on location in proc array - pproc_addr is not neccessary to get the address of a process if we know its number - local proc variables in system calls implementation (sys_task) conflicts with the global proc array of all process, therefore the variable were renamed to proc_nr as they hold the process number
2009-09-15 11:57:22 +02:00
if (! isokendpt(m_ptr->SIG_ENDPT, &proc_nr)) return(EINVAL);
if (iskerneln(proc_nr)) return(EPERM);
rp = proc_addr(proc_nr);
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
/* Copy in the sigcontext structure. */
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
if((r=data_copy(m_ptr->SIG_ENDPT, (vir_bytes) m_ptr->SIG_CTXT_PTR,
Removal of the system task * Userspace change to use the new kernel calls - _taskcall(SYSTASK...) changed to _kernel_call(...) - int 32 reused for the kernel calls - _do_kernel_call() to make the trap to kernel - kernel_call() to make the actuall kernel call from C using _do_kernel_call() - unlike ipc call the kernel call always succeeds as kernel is always available, however, kernel may return an error * Kernel side implementation of kernel calls - the SYSTEm task does not run, only the proc table entry is preserved - every data_copy(SYSTEM is no data_copy(KERNEL - "locking" is an empty operation now as everything runs in kernel - sys_task() is replaced by kernel_call() which copies the message into kernel, dispatches the call to its handler and finishes by either copying the results back to userspace (if need be) or by suspending the process because of VM - suspended processes are later made runnable once the memory issue is resolved, picked up by the scheduler and only at this time the call is resumed (in fact restarted) which does not need to copy the message from userspace as the message is already saved in the process structure. - no ned for the vmrestart queue, the scheduler will restart the system calls - no special case in do_vmctl(), all requests remove the RTS_VMREQUEST flag
2010-02-09 16:20:09 +01:00
KERNEL, (vir_bytes) &sc, sizeof(struct sigcontext))) != OK)
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
return r;
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
Restore user-owned bits from PSW after a signal handler, instead of copying complete PSW after signal handler. This fixes a psw corruption bug reported by Jens de Smit <jst260@few.vu.nl>.
2007-05-08 17:43:00 +02:00
/* Restore user bits of psw from sc, maintain system bits from proc. */
sc.sc_psw = (sc.sc_psw & X86_FLAGS_USER) |
(rp->p_reg.psw & ~X86_FLAGS_USER);
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
Replace MACHINE/CHIP macros with compiler macros
2012-08-06 12:55:50 +02:00
#if defined(__i386__)
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
/* Don't panic kernel if user gave bad selectors. */
sc.sc_cs = rp->p_reg.cs;
sc.sc_ds = rp->p_reg.ds;
sc.sc_es = rp->p_reg.es;
also don't let user process change ss segment selector when returning from signal.
2009-09-25 19:44:26 +02:00
sc.sc_ss = rp->p_reg.ss;
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
sc.sc_fs = rp->p_reg.fs;
sc.sc_gs = rp->p_reg.gs;
#endif
/* Restore the registers. */
FPU context switching support by Evgeniy Ivanov.
2009-12-02 14:01:48 +01:00
memcpy(&rp->p_reg, &sc.sc_regs, sizeof(sigregs));
Replace MACHINE/CHIP macros with compiler macros
2012-08-06 12:55:50 +02:00
#if defined(__i386__)
FPU context switching support by Evgeniy Ivanov.
2009-12-02 14:01:48 +01:00
if(sc.sc_flags & MF_FPU_INITIALIZED)
{
use linker to align fpu state save area
2012-04-19 15:06:47 +02:00
memcpy(rp->p_seg.fpu_state, &sc.sc_fpu_state, FPU_XFP_SIZE);
FPU context switching support by Evgeniy Ivanov.
2009-12-02 14:01:48 +01:00
rp->p_misc_flags |= MF_FPU_INITIALIZED; /* Restore math usage flag. */
Lazy FPU - FPU context is stored only if conflict between 2 FPU users or while exporting context of a process to userspace while it is the active user of FPU - FPU has its owner (fpu_owner) which points to the process whose state is currently loaded in FPU - the FPU exception is only turned on when scheduling a process which is not the owner of FPU - FPU state is restored for the process that generated the FPU exception. This process runs immediately without letting scheduler to pick a new process to resolve the FPU conflict asap, to minimize the FPU thrashing and FPU exception hadler execution - faster all non-FPU-exception kernel entries as FPU state is not checked nor saved - removed MF_USED_FPU flag, only MF_FPU_INITIALIZED remains to signal that a process has used FPU in the past
2010-06-07 09:43:17 +02:00
/* force reloading FPU */
SMP - lazy FPU - when a process is migrated to a different CPU it may have an active FPU context in the processor registers. We must save it and migrate it together with the process.
2010-09-15 16:11:25 +02:00
release_fpu(rp);
FPU context switching support by Evgeniy Ivanov.
2009-12-02 14:01:48 +01:00
}
#endif
Remove leftover PowerPC cruft. Reported by Evgeniy Ivanov.
2009-07-07 20:55:11 +02:00
kernel: fix case of EAX getting clobbered after sigreturn.
2010-07-20 19:10:09 +02:00
rp->p_misc_flags |= MF_CONTEXT_SET;
Reorganized system call library; uses separate file per call now. New configuration header file to include/ exclude functionality. Extracted privileged features from struct proc and create new struct priv. Renamed various system calls for readability.
2005-07-14 17:12:12 +02:00
return(OK);
}
#endif /* USE_SIGRETURN */
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