freebsd-dev/sys/kern/subr_trap.c

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1993-06-12 14:58:17 +00:00
/*-
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
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*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
genassym.c: Remove NKMEMCLUSTERS, it is no longer define or used. locores.s: Fix comment on PTDpde and APTDpde to be pde instead of pte Add new equation for calculating location of Sysmap Remove Bill's old #ifdef garbage for counting up memory, that stuff will never be made to work and was just cluttering up the file. Add code that places the PTD, page table pages, and kernel stack below the 640k ISA hole if there is room for it, otherwise put this stuff all at 1MB. This fixes the 28K bogusity in the boot blocks, that can now go away! Fix the caclulation of where first is to be dependent on NKPDE so that we can skip over the above mentioned areas. The 28K thing is now 44K in size due to the increase in kernel virtual memory space, but since we no longer have to worry about that this is no big deal. Use if NNPX > 0 instead of ifdef NPX for floating point code. machdep.c Change the calculation of for the buffer cache to be 20% of all memory above 2MB and add back the upper limit of 2/5's of the VM_KMEM_SIZE so that we do not eat ALL of the kernel memory space on large memory machines, note that this will not even come into effect unless you have more than 32MB. The current buffer cache limit is 6.7MB due to this caclulation. It seems that we where erroniously allocating bufpages pages for buffer_map. buffer_map is UNUSED in this implementation of the buffer cache, but since the map is referenced in several if statements a quick fix was to simply allocate 1 vm page (but no real memory) to it. pmap.h Remove rcsid, don't want them in the kernel files! Removed some cruft inside an #ifdef DEBUGx that caused compiler errors if you where compiling this for debug. Use the #defines for PD_SHIFT and PG_SHIFT in place of constants. trap.c: Remove patch kit header and rcsid, fix $Id$. Now include "npx.h" and use NNPX for controlling the floating point code. Remove a now completly invalid check for a maximum virtual address, the virtual address now ends at 0xFFFFFFFF so there is no more MAX!! (Thanks David, I completly missed that one!) vm_machdep.c Remove patch kit header and rcsid, fix $Id$. Now include "npx.h" and use NNPX for controlling the floating point code. Replace several 0xFE00000 constants with KERNBASE
1993-10-15 10:34:29 +00:00
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.58 1995/07/30 17:49:24 davidg Exp $
1993-06-12 14:58:17 +00:00
*/
/*
1994-06-11 05:13:33 +00:00
* 386 Trap and System call handling
1993-06-12 14:58:17 +00:00
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kernel.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
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#ifdef KTRACE
#include <sys/ktrace.h>
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#endif
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/trap.h>
#include <machine/../isa/isa_device.h>
1993-06-12 14:58:17 +00:00
#ifdef POWERFAIL_NMI
# include <syslog.h>
# include <machine/clock.h>
#endif
#include "isa.h"
#include "npx.h"
1993-06-12 14:58:17 +00:00
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
1993-06-12 14:58:17 +00:00
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
#define MAX_TRAP_MSG 27
char *trap_msg[] = {
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 0 unused */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"privileged instruction fault", /* 1 T_PRIVINFLT */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 2 unused */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"breakpoint instruction fault", /* 3 T_BPTFLT */
"", /* 4 unused */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 5 unused */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 8 unused */
"general protection fault", /* 9 T_PROTFLT */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 13 unused */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"alignment fault", /* 14 T_ALIGNFLT */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
"", /* 15 unused */
"", /* 16 unused */
"", /* 17 unused */
First steps in rewriting locore.s, and making info useful when the machine panics. i386/i386/locore.s: 1) got rid of most .set directives that were being used like #define's, and replaced them with appropriate #define's in the appropriate header files (accessed via genassym). 2) added comments to header inclusions and global definitions, and global variables 3) replaced some hardcoded constants with cpp defines (such as PDESIZE and others) 4) aligned all comments to the same column to make them easier to read 5) moved macro definitions for ENTRY, ALIGN, NOP, etc. to /sys/i386/include/asmacros.h 6) added #ifdef BDE_DEBUGGER around all of Bruce's debugger code 7) added new global '_KERNend' to store last location+1 of kernel 8) cleaned up zeroing of bss so that only bss is zeroed 9) fix zeroing of page tables so that it really does zero them all - not just if they follow the bss. 10) rewrote page table initialization code so that 1) works correctly and 2) write protects the kernel text by default 11) properly initialize the kernel page directory, upages, p0stack PT, and page tables. The previous scheme was more than a bit screwy. 12) change allocation of virtual area of IO hole so that it is fixed at KERNBASE + 0xa0000. The previous scheme put it right after the kernel page tables and then later expected it to be at KERNBASE +0xa0000 13) change multiple bogus settings of user read/write of various areas of kernel VM - including the IO hole; we should never be accessing the IO hole in user mode through the kernel page tables 14) split kernel support routines such as bcopy, bzero, copyin, copyout, etc. into a seperate file 'support.s' 15) split swtch and related routines into a seperate 'swtch.s' 16) split routines related to traps, syscalls, and interrupts into a seperate file 'exception.s' 17) remove some unused global variables from locore that got inserted by Garrett when he pulled them out of some .h files. i386/isa/icu.s: 1) clean up global variable declarations 2) move in declaration of astpending and netisr i386/i386/pmap.c: 1) fix calculation of virtual_avail. It previously was calculated to be right in the middle of the kernel page tables - not a good place to start allocating kernel VM. 2) properly allocate kernel page dir/tables etc out of kernel map - previously only took out 2 pages. i386/i386/machdep.c: 1) modify boot() to print a warning that the system will reboot in PANIC_REBOOT_WAIT_TIME amount of seconds, and let the user abort with a key on the console. The machine will wait for ever if a key is typed before the reboot. The default is 15 seconds, but can be set to 0 to mean don't wait at all, -1 to mean wait forever, or any positive value to wait for that many seconds. 2) print "Rebooting..." just before doing it. kern/subr_prf.c: 1) remove PANICWAIT as it is deprecated by the change to machdep.c i386/i386/trap.c: 1) add table of trap type strings and use it to print a real trap/ panic message rather than just a number. Lot's of work to be done here, but this is the first step. Symbolic traceback is in the TODO. i386/i386/Makefile.i386: 1) add support in to build support.s, exception.s and swtch.s ...and various changes to various header files to make all of the above happen.
1993-11-13 02:25:21 +00:00
"integer divide fault", /* 18 T_DIVIDE */
"non-maskable interrupt trap", /* 19 T_NMI */
"overflow trap", /* 20 T_OFLOW */
"FPU bounds check fault", /* 21 T_BOUND */
"FPU device not available", /* 22 T_DNA */
"double fault", /* 23 T_DOUBLEFLT */
"FPU operand fetch fault", /* 24 T_FPOPFLT */
"invalid TSS fault", /* 25 T_TSSFLT */
"segment not present fault", /* 26 T_SEGNPFLT */
"stack fault", /* 27 T_STKFLT */
};
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
int sig, s;
while ((sig = CURSIG(p)) != 0)
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrunqueue ourselves but before we
* mi_switch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while ((sig = CURSIG(p)) != 0)
postsig(sig);
}
/*
* Charge system time if profiling.
*/
if (p->p_flag & P_PROFIL) {
u_quad_t ticks = p->p_sticks - oticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame->tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame->tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpriority = p->p_priority;
}
1993-06-12 14:58:17 +00:00
/*
* trap(frame):
* Exception, fault, and trap interface to the FreeBSD kernel.
* This common code is called from assembly language IDT gate entry
1993-06-12 14:58:17 +00:00
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed.
1993-06-12 14:58:17 +00:00
*/
/*ARGSUSED*/
void
1993-06-12 14:58:17 +00:00
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code;
#ifdef DIAGNOSTIC
u_long eva;
#endif
1993-06-12 14:58:17 +00:00
type = frame.tf_trapno;
code = frame.tf_err;
1995-05-30 08:16:23 +00:00
1993-06-12 14:58:17 +00:00
if (ISPL(frame.tf_cs) == SEL_UPL) {
/* user trap */
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
ucode = type;
i = SIGILL;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
astoff();
cnt.v_soft++;
if (p->p_flag & P_OWEUPC) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
1993-06-12 14:58:17 +00:00
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
case T_STKFLT: /* stack fault */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
case T_TSSFLT: /* invalid TSS fault */
case T_DOUBLEFLT: /* double fault */
default:
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
1993-06-12 14:58:17 +00:00
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == -1)
return;
if (i == 0)
goto out;
1993-06-12 14:58:17 +00:00
ucode = T_PAGEFLT;
break;
1993-06-12 14:58:17 +00:00
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
1993-06-12 14:58:17 +00:00
#if NISA > 0
case T_NMI:
#ifdef POWERFAIL_NMI
goto handle_powerfail;
#else /* !POWERFAIL_NMI */
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif /* DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
panic("NMI indicates hardware failure");
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
1993-06-12 14:58:17 +00:00
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
1993-06-12 14:58:17 +00:00
case T_BOUND: /* bounds check fault */
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
1993-06-12 14:58:17 +00:00
case T_DNA:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna())
return;
#endif /* NNPX > 0 */
1993-06-12 14:58:17 +00:00
1995-05-30 08:16:23 +00:00
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) {
if (!(frame.tf_eflags & PSL_T))
return;
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
}
/* else ucode = emulator_only_knows() XXX */
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
i = SIGFPE;
ucode = FPE_FPU_NP_TRAP;
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(&frame, FALSE);
return;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
/*
* Invalid segment selectors and out of bounds
* %eip's and %esp's can be set up in user mode.
* This causes a fault in kernel mode when the
* kernel tries to return to user mode. We want
* to get this fault so that we can fix the
* problem here and not have to check all the
* selectors and pointers when the user changes
* them.
*/
#define MAYBE_DORETI_FAULT(where, whereto) \
do { \
if (frame.tf_eip == (int)where) { \
frame.tf_eip = (int)whereto; \
return; \
} \
} while (0)
if (intr_nesting_level == 0) {
MAYBE_DORETI_FAULT(doreti_iret,
doreti_iret_fault);
MAYBE_DORETI_FAULT(doreti_popl_ds,
doreti_popl_ds_fault);
MAYBE_DORETI_FAULT(doreti_popl_es,
doreti_popl_es_fault);
}
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
Fix security holes in sigreturn(), ptrace() and procfs. sigreturn() attempted to check for insecure and fatal eflags and segment selectors, but missed many cases and got the IOPL check back to front. The other syscalls didn't check at all. sys_process.c, machdep.c: Only allow PT_WRITE_U to write to the registers (ordinary and FP). psl.h, locore.s, machdep.c: Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed to assume anything about the reserved bits. Use PSL_USERCHANGE and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER. exception.s: Define a private label for use by doreti when returning to user mode fails. machdep.c: In syscalls, allow changing only the eflags that can be changed on 486's in user mode (no longer attempt to allow benign IOPL changes; allow changing the nasty PSL_NT; don't allow changing the i586 bits). Don't attempt to check all the cases involving invalid selectors and %eip's. Just check for privilege violations and let the invalid things cause a trap. procfs_machdep.c: Call the ptrace register functions to do all the work for reading and writing ordinary registers and for single stepping. trap.c: Ignore traps caused by PSL_NT being set. Previously, users could cause a fatal trap in user mode by setting PSL_NT and executing an iret, and a fatal trap in kernel mode by setting PSL_NT and making a syscall. PSL_NT was cleared too late and not in enough modes to fix the problem. Make all traps in user mode (except T_NMI) nonfatal. Recover from traps caused by attempting to load invalid user registers in doreti by restarting the traps so that they appear to occur in user mode. --- Fix bogons that I noticed while fixing the above: psl.h: Fix some comments. Uniformize idempotency ifdef. exception.s, machdep.c: Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic non-unique) trap numbers. Replace rsvd[1-14] by rsvd. locore.s: Enable alignment check flag on 486's and 586's. machdep.c: Use a better type for kstack[]. Use TFREGP() to find the registers. Reformat ptrace functions from SEF to something closer to KNF. procfs_machdep.c: The wrong pointer to the registers got fixed as a side effect. Implement reading and writing of FP registers. /proc/*/*regs now work (only) for processes that are in memory. Clean up comments. trap.c, trap.h: Remove unused trap types.
1995-01-14 13:20:26 +00:00
case T_TSSFLT:
/*
* PSL_NT can be set in user mode and isn't cleared
* automatically when the kernel is entered. This
* causes a TSS fault when the kernel attempts to
* `iret' because the TSS link is uninitialized. We
* want to get this fault so that we can fix the
* problem here and not every time the kernel is
* entered.
*/
if (frame.tf_eflags & PSL_NT) {
frame.tf_eflags &= ~PSL_NT;
return;
}
break;
#ifdef DDB
case T_BPTFLT:
case T_TRCTRAP:
if (kdb_trap (type, 0, &frame))
1993-06-12 14:58:17 +00:00
return;
break;
#else
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
1993-06-12 14:58:17 +00:00
/* Q: how do we turn it on again? */
frame.tf_eflags &= ~PSL_T;
return;
1993-06-12 14:58:17 +00:00
#endif
1995-05-30 08:16:23 +00:00
#if NISA > 0
case T_NMI:
#ifdef POWERFAIL_NMI
#ifndef TIMER_FREQ
# define TIMER_FREQ 1193182
#endif
handle_powerfail:
{
static unsigned lastalert = 0;
if(time.tv_sec - lastalert > 10)
{
log(LOG_WARNING, "NMI: power fail\n");
sysbeep(TIMER_FREQ/880, hz);
lastalert = time.tv_sec;
}
return;
}
#else /* !POWERFAIL_NMI */
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif /* DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
}
trap_fatal(&frame);
return;
1993-06-12 14:58:17 +00:00
}
trapsignal(p, i, ucode);
#ifdef DEBUG
eva = rcr2();
if (type <= MAX_TRAP_MSG) {
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uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
1993-06-12 14:58:17 +00:00
out:
userret(p, &frame, sticks);
}
#ifdef notyet
/*
* This version doesn't allow a page fault to user space while
* in the kernel. The rest of the kernel needs to be made "safe"
* before this can be used. I think the only things remaining
* to be made safe are the iBCS2 code and the process tracing/
* debugging code.
*/
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm = NULL;
vm_map_t map = 0;
int rv = 0;
vm_prot_t ftype;
int eva;
struct proc *p = curproc;
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
if (va < VM_MIN_KERNEL_ADDRESS) {
vm_offset_t v;
vm_page_t ptepg;
if (p == NULL ||
(!usermode && va < VM_MAXUSER_ADDRESS &&
(curpcb == NULL || curpcb->pcb_onfault == NULL))) {
trap_fatal(frame);
return (-1);
}
/*
* This is a fault on non-kernel virtual memory.
* vm is initialized above to NULL. If curproc is NULL
* or curproc->p_vmspace is NULL the fault is fatal.
*/
vm = p->p_vmspace;
if (vm == NULL)
goto nogo;
map = &vm->vm_map;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
v = (vm_offset_t) vtopte(va);
/* Fault the pte only if needed: */
if (*((int *)vtopte(v)) == 0)
(void) vm_fault(map, trunc_page(v), VM_PROT_WRITE, FALSE);
pmap_use_pt( vm_map_pmap(map), va);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
pmap_unuse_pt( vm_map_pmap(map), va);
--p->p_lock;
} else {
/*
* Don't allow user-mode faults in kernel address space.
*/
if (usermode)
goto nogo;
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(kernel_map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb && curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
return (-1);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
#endif
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm = NULL;
vm_map_t map = 0;
int rv = 0;
vm_prot_t ftype;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
if (va >= KERNBASE) {
/*
* Don't allow user-mode faults in kernel address space.
*/
if (usermode)
goto nogo;
map = kernel_map;
} else {
/*
* This is a fault on non-kernel virtual memory.
* vm is initialized above to NULL. If curproc is NULL
* or curproc->p_vmspace is NULL the fault is fatal.
*/
if (p != NULL)
vm = p->p_vmspace;
if (vm == NULL)
goto nogo;
map = &vm->vm_map;
}
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t v;
vm_page_t ptepg;
1993-06-12 14:58:17 +00:00
/*
* Keep swapout from messing with us during this
* critical time.
1993-06-12 14:58:17 +00:00
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
v = (vm_offset_t) vtopte(va);
/* Fault the pte only if needed: */
if (*((int *)vtopte(v)) == 0)
(void) vm_fault(map, trunc_page(v), VM_PROT_WRITE, FALSE);
pmap_use_pt( vm_map_pmap(map), va);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
pmap_unuse_pt( vm_map_pmap(map), va);
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
1993-06-12 14:58:17 +00:00
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb && curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
1993-06-12 14:58:17 +00:00
}
trap_fatal(frame);
return (-1);
1993-06-12 14:58:17 +00:00
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap_fatal(frame)
struct trapframe *frame;
{
int code, type, eva;
struct soft_segment_descriptor softseg;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
if (type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
type, trap_msg[type],
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
if (type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip);
printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n",
softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
printf(" = DPL %d, pres %d, def32 %d, gran %d\n",
softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran);
printf("processor eflags = ");
if (frame->tf_eflags & PSL_T)
printf("trace/trap, ");
if (frame->tf_eflags & PSL_I)
printf("interrupt enabled, ");
if (frame->tf_eflags & PSL_NT)
printf("nested task, ");
if (frame->tf_eflags & PSL_RF)
printf("resume, ");
if (frame->tf_eflags & PSL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%lu (%s)\n",
(u_long)curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#ifdef DDB
if (kdb_trap (type, 0, frame))
return;
#endif
if (type <= MAX_TRAP_MSG)
panic(trap_msg[type]);
else
panic("unknown/reserved trap");
1993-06-12 14:58:17 +00:00
}
/*
* Compensate for 386 brain damage (missing URKR).
* This is a little simpler than the pagefault handler in trap() because
* it the page tables have already been faulted in and high addresses
* are thrown out early for other reasons.
1993-06-12 14:58:17 +00:00
*/
int trapwrite(addr)
unsigned addr;
{
struct proc *p;
vm_offset_t va, v;
struct vmspace *vm;
int rv;
1993-06-12 14:58:17 +00:00
va = trunc_page((vm_offset_t)addr);
/*
* XXX - MAX is END. Changed > to >= for temp. fix.
*/
if (va >= VM_MAXUSER_ADDRESS)
return (1);
p = curproc;
vm = p->p_vmspace;
++p->p_lock;
if ((caddr_t)va >= vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
--p->p_lock;
return (1);
}
}
v = trunc_page(vtopte(va));
/*
* wire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
}
/*
* fault the data page
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
/*
* unwire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
}
--p->p_lock;
if (rv != KERN_SUCCESS)
return 1;
return (0);
1993-06-12 14:58:17 +00:00
}
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
/*ARGSUSED*/
void
1993-06-12 14:58:17 +00:00
syscall(frame)
struct trapframe frame;
1993-06-12 14:58:17 +00:00
{
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error;
1993-06-12 14:58:17 +00:00
int args[8], rval[2];
u_int code;
1993-06-12 14:58:17 +00:00
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
1993-06-12 14:58:17 +00:00
panic("syscall");
p->p_md.md_regs = (int *)&frame;
params = (caddr_t)frame.tf_esp + sizeof(int);
code = frame.tf_eax;
/*
* Need to check if this is a 32 bit or 64 bit syscall.
*/
if (code == SYS_syscall) {
/*
* Code is first argument, followed by actual args.
*/
code = fuword(params);
params += sizeof(int);
} else if (code == SYS___syscall) {
/*
* Like syscall, but code is a quad, so as to maintain
* quad alignment for the rest of the arguments.
*/
code = fuword(params);
params += sizeof(quad_t);
1993-06-12 14:58:17 +00:00
}
if (p->p_sysent->sv_mask)
code &= p->p_sysent->sv_mask;
1995-05-30 08:16:23 +00:00
if (code >= p->p_sysent->sv_size)
callp = &p->p_sysent->sv_table[0];
else
callp = &p->p_sysent->sv_table[code];
1993-06-12 14:58:17 +00:00
if ((i = callp->sy_narg * sizeof(int)) &&
1993-06-12 14:58:17 +00:00
(error = copyin(params, (caddr_t)args, (u_int)i))) {
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
1993-06-12 14:58:17 +00:00
#endif
goto bad;
1993-06-12 14:58:17 +00:00
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
1993-06-12 14:58:17 +00:00
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
1993-06-12 14:58:17 +00:00
error = (*callp->sy_call)(p, args, rval);
switch (error) {
case 0:
1993-06-12 14:58:17 +00:00
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
1993-06-12 14:58:17 +00:00
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
1993-06-12 14:58:17 +00:00
case ERESTART:
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes.
*/
frame.tf_eip -= 7;
break;
case EJUSTRETURN:
break;
default:
bad:
if (p->p_sysent->sv_errsize)
if (error >= p->p_sysent->sv_errsize)
error = -1; /* XXX */
1995-05-30 08:16:23 +00:00
else
error = p->p_sysent->sv_errtbl[error];
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
1993-06-12 14:58:17 +00:00
}
userret(p, &frame, sticks);
1993-06-12 14:58:17 +00:00
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
#ifdef COMPAT_LINUX
/*
* linux_syscall(frame):
*/
/*ARGSUSED*/
void
linux_syscall(frame)
struct trapframe frame;
{
int i;
struct proc *p = curproc;
struct sysent *callp;
u_quad_t sticks;
int error;
int rval[2];
u_int code;
struct linux_syscall_args {
1995-06-11 19:33:05 +00:00
int arg1;
int arg2;
int arg3;
int arg4;
int arg5;
} args;
1995-06-11 19:33:05 +00:00
args.arg1 = frame.tf_ebx;
args.arg2 = frame.tf_ecx;
args.arg3 = frame.tf_edx;
args.arg4 = frame.tf_esi;
args.arg5 = frame.tf_edi;
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("linux syscall");
p->p_md.md_regs = (int *)&frame;
code = frame.tf_eax;
if (p->p_sysent->sv_mask)
code &= p->p_sysent->sv_mask;
if (code >= p->p_sysent->sv_size)
callp = &p->p_sysent->sv_table[0];
else
callp = &p->p_sysent->sv_table[code];
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, (int *)&args);
#endif
rval[0] = 0;
error = (*callp->sy_call)(p, &args, rval);
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
/* Reconstruct pc, subtract size of int 0x80 */
frame.tf_eip -= 2;
break;
case EJUSTRETURN:
break;
default:
if (p->p_sysent->sv_errsize)
if (error >= p->p_sysent->sv_errsize)
error = -1; /* XXX */
1995-05-30 08:16:23 +00:00
else
error = p->p_sysent->sv_errtbl[error];
frame.tf_eax = -error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
}
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
#endif /* COMPAT_LINUX */