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Move the check to see if we are tracing a function with the DTrace Function

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Boundary Trace to assembly to reduce the overhead of these checks.

Submitted by:	Howard Su <howard0su@gmail.com>
Relnotes:	Yes
Differential Revision:	https://reviews.freebsd.org/D4266
This commit is contained in:
Andrew Turner 2015-12-05 09:32:36 +00:00
parent 9a5d210cb4
commit c218815337
6 changed files with 62 additions and 37 deletions
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40
sys/arm/arm/exception.S
View File

@ -52,13 +52,15 @@
#include <machine/asm.h>
#include <machine/armreg.h>
#include <machine/asmacros.h>
#include <machine/trap.h>
__FBSDID("$FreeBSD$");
#ifdef KDTRACE_HOOKS
.bss
.align 4
.global _C_LABEL(dtrace_invop_calltrap_addr)
_C_LABEL(dtrace_invop_calltrap_addr):
.global _C_LABEL(dtrace_invop_jump_addr)
_C_LABEL(dtrace_invop_jump_addr):
.word 0
.word 0
#endif
@ -361,9 +363,39 @@ END(data_abort_entry)
*/
ASENTRY_NP(undefined_entry)
PUSHFRAMEINSVC /* mode stack, build trapframe there. */
mov r4, r0 /* R0 contains SPSR */
adr lr, exception_exit /* Return from handler via standard */
mov r0, sp /* exception exit routine. Pass the */
b undefinedinstruction /* trapframe to the handler. */
mov r0, sp /* exception exit routine. pass frame */
ldr r2, [sp, #(TF_PC)] /* load pc */
#if __ARM_ARCH >= 7
tst r4, #(PSR_T) /* test if PSR_T */
subne r2, r2, #(THUMB_INSN_SIZE)
subeq r2, r2, #(INSN_SIZE)
#else
sub r2, r2, #(INSN_SIZE) /* fix pc */
#endif
str r2, [sp, #TF_PC] /* store pc */
#ifdef KDTRACE_HOOKS
/* Check if dtrace is enabled */
ldr r1, =_C_LABEL(dtrace_invop_jump_addr)
ldr r3, [r1]
cmp r3, #0
beq undefinedinstruction
and r4, r4, #(PSR_MODE) /* Mask out unneeded bits */
cmp r4, #(PSR_USR32_MODE) /* Check if we came from usermode */
beq undefinedinstruction
ldr r4, [r2] /* load instrution */
ldr r1, =FBT_BREAKPOINT /* load fbt inv op */
cmp r1, r4
bne undefinedinstruction
bx r3 /* call invop_jump_addr */
#endif
b undefinedinstruction /* call stadnard handler */
END(undefined_entry)
/*

1
sys/arm/arm/genassym.c
View File

@ -118,6 +118,7 @@ ASSYM(MD_TP, offsetof(struct mdthread, md_tp));
ASSYM(MD_RAS_START, offsetof(struct mdthread, md_ras_start));
ASSYM(MD_RAS_END, offsetof(struct mdthread, md_ras_end));
ASSYM(TF_SPSR, offsetof(struct trapframe, tf_spsr));
ASSYM(TF_R0, offsetof(struct trapframe, tf_r0));
ASSYM(TF_R1, offsetof(struct trapframe, tf_r1));
ASSYM(TF_PC, offsetof(struct trapframe, tf_pc));

11
sys/arm/arm/trap-v6.c
View File

@ -66,6 +66,10 @@ __FBSDID("$FreeBSD$");
#include <machine/db_machdep.h>
#endif
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
#endif
extern char fusubailout[];
extern char cachebailout[];
@ -561,6 +565,13 @@ abort_fatal(struct trapframe *tf, u_int idx, u_int fsr, u_int far,
const char *rw_mode;
usermode = TRAPF_USERMODE(tf);
#ifdef KDTRACE_HOOKS
if (!usermode) {
if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, far))
return (0);
}
#endif
mode = usermode ? "user" : "kernel";
rw_mode = fsr & FSR_WNR ? "write" : "read";
disable_interrupts(PSR_I|PSR_F);

16
sys/arm/arm/undefined.c
View File

@ -99,10 +99,6 @@ __FBSDID("$FreeBSD$");
#define COPROC_VFP 10
#ifdef KDTRACE_HOOKS
int (*dtrace_invop_jump_addr)(struct trapframe *);
#endif
static int gdb_trapper(u_int, u_int, struct trapframe *, int);
LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
@ -206,12 +202,6 @@ undefinedinstruction(struct trapframe *frame)
PCPU_INC(cnt.v_trap);
#if __ARM_ARCH >= 7
if ((frame->tf_spsr & PSR_T) != 0)
frame->tf_pc -= THUMB_INSN_SIZE;
else
#endif
frame->tf_pc -= INSN_SIZE;
fault_pc = frame->tf_pc;
/*
@ -350,12 +340,6 @@ undefinedinstruction(struct trapframe *frame)
#endif
return;
}
#ifdef KDTRACE_HOOKS
else if (dtrace_invop_jump_addr != 0) {
dtrace_invop_jump_addr(frame);
return;
}
#endif
else
panic("Undefined instruction in kernel.\n");
}

1
sys/arm/include/trap.h
View File

@ -7,4 +7,5 @@
#define GDB5_BREAKPOINT 0xe7ffdefe
#define PTRACE_BREAKPOINT 0xe7fffff0
#define KERNEL_BREAKPOINT 0xe7ffffff
#define FBT_BREAKPOINT 0xe7f000f0
#endif /* _MACHINE_TRAP_H_ */

30
sys/cddl/dev/fbt/arm/fbt_isa.c
View File

@ -35,11 +35,10 @@
#include <sys/param.h>
#include <sys/dtrace.h>
#include <machine/trap.h>
#include "fbt.h"
#define FBT_PATCHVAL 0xe7f000f0 /* Specified undefined instruction */
#define FBT_PUSHM 0xe92d0000
#define FBT_POPM 0xe8bd0000
#define FBT_JUMP 0xea000000
@ -53,15 +52,20 @@ fbt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t rval)
struct trapframe *frame = (struct trapframe *)stack;
solaris_cpu_t *cpu = &solaris_cpu[curcpu];
fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)];
register_t fifthparam;
for (; fbt != NULL; fbt = fbt->fbtp_hashnext) {
if ((uintptr_t)fbt->fbtp_patchpoint == addr) {
cpu->cpu_dtrace_caller = addr;
/* TODO: Need 5th parameter from stack */
/* Get 5th parameter from stack */
DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
fifthparam = *(register_t *)frame->tf_usr_sp;
DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | CPU_DTRACE_BADADDR);
dtrace_probe(fbt->fbtp_id, frame->tf_r0,
frame->tf_r1, frame->tf_r2,
frame->tf_r3, 0);
frame->tf_r3, fifthparam);
cpu->cpu_dtrace_caller = 0;
@ -77,7 +81,7 @@ fbt_patch_tracepoint(fbt_probe_t *fbt, fbt_patchval_t val)
{
*fbt->fbtp_patchpoint = val;
cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4);
cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, sizeof(val));
}
int
@ -104,13 +108,6 @@ fbt_provide_module_function(linker_file_t lf, int symindx,
if (name[0] == '_' && name[1] == '_')
return (0);
/*
* Architecture-specific exclusion list, largely to do with FBT trap
* processing, to prevent reentrance.
*/
if (strcmp(name, "undefinedinstruction") == 0)
return (0);
instr = (uint32_t *)symval->value;
limit = (uint32_t *)(symval->value + symval->size);
@ -125,12 +122,12 @@ fbt_provide_module_function(linker_file_t lf, int symindx,
fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO);
fbt->fbtp_name = name;
fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
name, FBT_ENTRY, 3, fbt);
name, FBT_ENTRY, 2, fbt);
fbt->fbtp_patchpoint = instr;
fbt->fbtp_ctl = lf;
fbt->fbtp_loadcnt = lf->loadcnt;
fbt->fbtp_savedval = *instr;
fbt->fbtp_patchval = FBT_PATCHVAL;
fbt->fbtp_patchval = FBT_BREAKPOINT;
fbt->fbtp_rval = DTRACE_INVOP_PUSHM;
fbt->fbtp_symindx = symindx;
@ -157,7 +154,6 @@ fbt_provide_module_function(linker_file_t lf, int symindx,
start = (uint32_t *)symval->value;
if (target >= limit || target < start)
break;
instr++; /* skip delay slot */
}
}
@ -171,7 +167,7 @@ fbt_provide_module_function(linker_file_t lf, int symindx,
fbt->fbtp_name = name;
if (retfbt == NULL) {
fbt->fbtp_id = dtrace_probe_create(fbt_id, modname,
name, FBT_RETURN, 3, fbt);
name, FBT_RETURN, 2, fbt);
} else {
retfbt->fbtp_next = fbt;
fbt->fbtp_id = retfbt->fbtp_id;
@ -187,7 +183,7 @@ fbt_provide_module_function(linker_file_t lf, int symindx,
else
fbt->fbtp_rval = DTRACE_INVOP_POPM;
fbt->fbtp_savedval = *instr;
fbt->fbtp_patchval = FBT_PATCHVAL;
fbt->fbtp_patchval = FBT_BREAKPOINT;
fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)];
fbt_probetab[FBT_ADDR2NDX(instr)] = fbt;