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Fix the DTrace pid return trap interrupt vector. Previously we were using

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31, but that vector is reserved.

Without this fix, running dtrace -p <pid> would either cause the target
process to crash or the kernel to page fault.

Obtained from:	rpaulo
MFC after:	3days
This commit is contained in:
Ryan Stone 2011-11-07 01:53:25 +00:00
parent e6c503f75a
commit 166808c625
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=227290
6 changed files with 25 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
sys/amd64/amd64/trap.c
View File

@ -125,7 +125,7 @@ void dblfault_handler(struct trapframe *frame);
static int trap_pfault(struct trapframe *, int);
static void trap_fatal(struct trapframe *, vm_offset_t);
#define MAX_TRAP_MSG 30
#define MAX_TRAP_MSG 33
static char *trap_msg[] = {
"", /* 0 unused */
"privileged instruction fault", /* 1 T_PRIVINFLT */
@ -158,6 +158,9 @@ static char *trap_msg[] = {
"machine check trap", /* 28 T_MCHK */
"SIMD floating-point exception", /* 29 T_XMMFLT */
"reserved (unknown) fault", /* 30 T_RESERVED */
"", /* 31 unused (reserved) */
"DTrace pid return trap", /* 32 T_DTRACE_RET */
"DTrace fasttrap probe trap", /* 33 T_DTRACE_PROBE */
};
#ifdef KDB
@ -245,28 +248,26 @@ trap(struct trapframe *frame)
* handled the trap and modified the trap frame so that this
* function can return normally.
*/
if (dtrace_trap_func != NULL)
if ((*dtrace_trap_func)(frame, type))
goto out;
if (type == T_DTRACE_PROBE || type == T_DTRACE_RET ||
type == T_BPTFLT) {
struct reg regs;
fill_frame_regs(frame, &regs);
if (type == T_DTRACE_PROBE &&
dtrace_fasttrap_probe_ptr != NULL &&
dtrace_fasttrap_probe_ptr(&regs) == 0)
goto out;
if (type == T_BPTFLT &&
goto out;
else if (type == T_BPTFLT &&
dtrace_pid_probe_ptr != NULL &&
dtrace_pid_probe_ptr(&regs) == 0)
goto out;
if (type == T_DTRACE_RET &&
goto out;
else if (type == T_DTRACE_RET &&
dtrace_return_probe_ptr != NULL &&
dtrace_return_probe_ptr(&regs) == 0)
goto out;
}
if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
goto out;
#endif
if ((frame->tf_rflags & PSL_I) == 0) {

2
sys/amd64/include/segments.h
View File

@ -214,7 +214,7 @@ struct region_descriptor {
#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
#define IDT_DTRACE_RET 0x92 /* DTrace pid provider Interrupt Vector */
#define IDT_DTRACE_RET 0x20 /* DTrace pid provider Interrupt Vector */
/*
* Entries in the Global Descriptor Table (GDT)

4
sys/amd64/include/trap.h
View File

@ -62,8 +62,8 @@
#define T_MCHK 28 /* machine check trap */
#define T_XMMFLT 29 /* SIMD floating-point exception */
#define T_RESERVED 30 /* reserved (unknown) */
#define T_DTRACE_RET 31 /* DTrace pid return */
#define T_DTRACE_PROBE 32 /* DTrace fasttrap probe */
#define T_DTRACE_RET 32 /* DTrace pid return */
#define T_DTRACE_PROBE 33 /* DTrace fasttrap probe */
/* XXX most of the following codes aren't used, but could be. */

13
sys/i386/i386/trap.c
View File

@ -136,7 +136,7 @@ void dblfault_handler(void);
extern inthand_t IDTVEC(lcall_syscall);
#define MAX_TRAP_MSG 30
#define MAX_TRAP_MSG 33
static char *trap_msg[] = {
"", /* 0 unused */
"privileged instruction fault", /* 1 T_PRIVINFLT */
@ -169,6 +169,10 @@ static char *trap_msg[] = {
"machine check trap", /* 28 T_MCHK */
"SIMD floating-point exception", /* 29 T_XMMFLT */
"reserved (unknown) fault", /* 30 T_RESERVED */
"", /* 31 unused (reserved) */
"DTrace pid return trap", /* 32 T_DTRACE_RET */
"DTrace fasttrap probe trap", /* 33 T_DTRACE_PROBE */
};
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
@ -265,10 +269,6 @@ trap(struct trapframe *frame)
* handled the trap and modified the trap frame so that this
* function can return normally.
*/
if ((type == T_PROTFLT || type == T_PAGEFLT) &&
dtrace_trap_func != NULL)
if ((*dtrace_trap_func)(frame, type))
goto out;
if (type == T_DTRACE_PROBE || type == T_DTRACE_RET ||
type == T_BPTFLT) {
struct reg regs;
@ -287,6 +287,9 @@ trap(struct trapframe *frame)
dtrace_return_probe_ptr(&regs) == 0)
goto out;
}
if ((type == T_PROTFLT || type == T_PAGEFLT) &&
dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
goto out;
#endif
if ((frame->tf_eflags & PSL_I) == 0) {

2
sys/i386/include/segments.h
View File

@ -207,7 +207,7 @@ struct region_descriptor {
#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
#define IDT_DTRACE_RET 0x92 /* DTrace pid provider Interrupt Vector */
#define IDT_DTRACE_RET 0x20 /* DTrace pid provider Interrupt Vector */
/*
* Entries in the Global Descriptor Table (GDT)

4
sys/i386/include/trap.h
View File

@ -62,8 +62,8 @@
#define T_MCHK 28 /* machine check trap */
#define T_XMMFLT 29 /* SIMD floating-point exception */
#define T_RESERVED 30 /* reserved (unknown) */
#define T_DTRACE_RET 31 /* DTrace pid return */
#define T_DTRACE_PROBE 32 /* DTrace fasttrap probe */
#define T_DTRACE_RET 32 /* DTrace pid return */
#define T_DTRACE_PROBE 33 /* DTrace fasttrap probe */
/* XXX most of the following codes aren't used, but could be. */