svn commit: r291852 - in head/sys: arm/arm arm/include cddl/dev/fbt/arm
Howard Su
howard0su at gmail.com
Sat Dec 5 12:53:14 UTC 2015
On Saturday, December 5, 2015, Andrew Turner <andrew at freebsd.org> wrote:
> Author: andrew
> Date: Sat Dec 5 09:32:36 2015
> New Revision: 291852
> URL: https://svnweb.freebsd.org/changeset/base/291852
>
> Log:
> Move the check to see if we are tracing a function with the DTrace
> Function
> Boundary Trace to assembly to reduce the overhead of these checks.
>
> Submitted by: Howard Su <howard0su at gmail.com <javascript:;>>
> Relnotes: Yes
> Differential Revision: https://reviews.freebsd.org/D4266
>
> Modified:
> head/sys/arm/arm/exception.S
> head/sys/arm/arm/genassym.c
> head/sys/arm/arm/trap-v6.c
> head/sys/arm/arm/undefined.c
> head/sys/arm/include/trap.h
> head/sys/cddl/dev/fbt/arm/fbt_isa.c
>
> Modified: head/sys/arm/arm/exception.S
>
> ==============================================================================
> --- head/sys/arm/arm/exception.S Sat Dec 5 08:52:37 2015
> (r291851)
> +++ head/sys/arm/arm/exception.S Sat Dec 5 09:32:36 2015
> (r291852)
> @@ -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)
>
> /*
>
> Modified: head/sys/arm/arm/genassym.c
>
> ==============================================================================
> --- head/sys/arm/arm/genassym.c Sat Dec 5 08:52:37 2015 (r291851)
> +++ head/sys/arm/arm/genassym.c Sat Dec 5 09:32:36 2015 (r291852)
> @@ -118,6 +118,7 @@ ASSYM(MD_TP, offsetof(struct mdthread, m
> 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));
>
> Modified: head/sys/arm/arm/trap-v6.c
>
> ==============================================================================
> --- head/sys/arm/arm/trap-v6.c Sat Dec 5 08:52:37 2015 (r291851)
> +++ head/sys/arm/arm/trap-v6.c Sat Dec 5 09:32:36 2015 (r291852)
> @@ -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
> 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);
>
> Modified: head/sys/arm/arm/undefined.c
>
> ==============================================================================
> --- head/sys/arm/arm/undefined.c Sat Dec 5 08:52:37 2015
> (r291851)
> +++ head/sys/arm/arm/undefined.c Sat Dec 5 09:32:36 2015
> (r291852)
> @@ -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 *f
>
> 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 *f
> #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");
> }
>
> Modified: head/sys/arm/include/trap.h
>
> ==============================================================================
> --- head/sys/arm/include/trap.h Sat Dec 5 08:52:37 2015 (r291851)
> +++ head/sys/arm/include/trap.h Sat Dec 5 09:32:36 2015 (r291852)
> @@ -7,4 +7,5 @@
> #define GDB5_BREAKPOINT 0xe7ffdefe
> #define PTRACE_BREAKPOINT 0xe7fffff0
> #define KERNEL_BREAKPOINT 0xe7ffffff
> +#define FBT_BREAKPOINT 0xe7f000f0
> #endif /* _MACHINE_TRAP_H_ */
>
> Modified: head/sys/cddl/dev/fbt/arm/fbt_isa.c
>
> ==============================================================================
> --- head/sys/cddl/dev/fbt/arm/fbt_isa.c Sat Dec 5 08:52:37 2015
> (r291851)
> +++ head/sys/cddl/dev/fbt/arm/fbt_isa.c Sat Dec 5 09:32:36 2015
> (r291852)
> @@ -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 *sta
> 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, f
> {
>
> *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_
> 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_
> 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 @@ again:
> start = (uint32_t *)symval->value;
> if (target >= limit || target < start)
> break;
> - instr++; /* skip delay slot */
> }
> }
>
> @@ -171,7 +167,7 @@ again:
> 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 @@ again:
> 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;
>
> While I am here,
1. Remove a copy&paste code to skip "delay slot" which ARM doesn't have.
2. Support fifth arg in fbt. this leads to add missing KDTRACE hook code in
trap-v6.c
--
-Howard
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