Page MenuHomeFreeBSD
Files F144413118

D40963.id124639.diff
No OneTemporary
Actions

D40963.id124639.diff
View Options

diff --git a/sys/cddl/dev/kinst/riscv/kinst_isa.c b/sys/cddl/dev/kinst/riscv/kinst_isa.c
--- a/sys/cddl/dev/kinst/riscv/kinst_isa.c
+++ b/sys/cddl/dev/kinst/riscv/kinst_isa.c
@@ -14,20 +14,7 @@
#include "kinst.h"
-/*
- * Per-CPU trampolines used when the interrupted thread is executing with
- * interrupts disabled. If an interrupt is raised while executing a trampoline,
- * the interrupt thread cannot safely overwrite its trampoline if it hits a
- * kinst probe while executing the interrupt handler.
- */
-DPCPU_DEFINE_STATIC(uint8_t *, intr_tramp);
-
-/*
- * The double-breakpoint mechanism needs to save the current probe for the next
- * call to kinst_invop(). As with per-CPU trampolines, this also has to be done
- * per-CPU when interrupts are disabled.
- */
-DPCPU_DEFINE_STATIC(struct kinst_probe *, intr_probe);
+DPCPU_DEFINE_STATIC(struct kinst_cpu_state *, kinst_state);
#define _MATCH_REG(reg) \
(offsetof(struct trapframe, tf_ ## reg) / sizeof(register_t))
@@ -253,14 +240,14 @@
}
static void
-kinst_trampoline_populate(struct kinst_probe *kp, uint8_t *tramp)
+kinst_trampoline_populate(struct kinst_probe *kp)
{
static uint16_t nop = MATCH_C_NOP;
static uint32_t ebreak = MATCH_EBREAK;
int ilen;
ilen = kp->kp_md.instlen;
- kinst_memcpy(tramp, &kp->kp_savedval, ilen);
+ kinst_memcpy(kp->kp_tramp, &kp->kp_savedval, ilen);
/*
* Since we cannot encode large displacements in a single instruction
@@ -273,9 +260,9 @@
* Add a NOP after a compressed instruction for padding.
*/
if (ilen == INSN_C_SIZE)
- kinst_memcpy(&tramp[ilen], &nop, INSN_C_SIZE);
+ kinst_memcpy(&kp->kp_tramp[ilen], &nop, INSN_C_SIZE);
- kinst_memcpy(&tramp[INSN_SIZE], &ebreak, INSN_SIZE);
+ kinst_memcpy(&kp->kp_tramp[INSN_SIZE], &ebreak, INSN_SIZE);
fence_i();
}
@@ -306,27 +293,26 @@
kinst_invop(uintptr_t addr, struct trapframe *frame, uintptr_t scratch)
{
solaris_cpu_t *cpu;
+ struct kinst_cpu_state *ks;
struct kinst_probe *kp;
- uint8_t *tramp;
- /*
- * Use per-CPU trampolines and probes if the thread executing the
- * instruction was executing with interrupts disabled.
- */
- if ((frame->tf_sstatus & SSTATUS_SPIE) == 0) {
- tramp = DPCPU_GET(intr_tramp);
- kp = DPCPU_GET(intr_probe);
- } else {
- tramp = curthread->t_kinst_tramp;
- kp = curthread->t_kinst_curprobe;
- }
+ ks = DPCPU_GET(kinst_state);
/*
* Detect if the breakpoint was triggered by the trampoline, and
* manually set the PC to the next instruction.
*/
- if (addr == (uintptr_t)(tramp + INSN_SIZE))
- return (kinst_jump_next_instr(frame, kp));
+ if (ks->state == KINST_PROBE_FIRED &&
+ addr == (uintptr_t)(ks->kp->kp_tramp + INSN_SIZE)) {
+ /*
+ * Restore interrupts if they were enabled prior to the first
+ * breakpoint.
+ */
+ if ((ks->status & SSTATUS_SPIE) != 0)
+ frame->tf_sstatus |= SSTATUS_SPIE;
+ ks->state = KINST_PROBE_ARMED;
+ return (kinst_jump_next_instr(frame, ks->kp));
+ }
LIST_FOREACH(kp, KINST_GETPROBE(addr), kp_hashnext) {
if ((uintptr_t)kp->kp_patchpoint == addr)
@@ -340,10 +326,14 @@
dtrace_probe(kp->kp_id, 0, 0, 0, 0, 0);
cpu->cpu_dtrace_caller = 0;
- if (kp->kp_md.emulate)
+ ks->state = KINST_PROBE_FIRED;
+
+ if (kp->kp_md.emulate) {
+ ks->state = KINST_PROBE_ARMED;
return (kinst_emulate(frame, kp));
+ }
- if (tramp == NULL) {
+ if (kp->kp_tramp == NULL) {
/*
* A trampoline allocation failed, so this probe is
* effectively disabled. Restore the original
@@ -356,12 +346,16 @@
kinst_patch_tracepoint(kp, kp->kp_savedval);
frame->tf_sepc = (register_t)kp->kp_patchpoint;
} else {
- kinst_trampoline_populate(kp, tramp);
- frame->tf_sepc = (register_t)tramp;
- if ((frame->tf_sstatus & SSTATUS_SPIE) == 0)
- DPCPU_SET(intr_probe, kp);
- else
- curthread->t_kinst_curprobe = kp;
+ kinst_trampoline_populate(kp);
+ frame->tf_sepc = (register_t)kp->kp_tramp;
+
+ /*
+ * Cache the current SSTATUS and clear interrupts for the
+ * duration of the double breakpoint.
+ */
+ ks->status = frame->tf_sstatus;
+ ks->kp = kp;
+ frame->tf_sstatus &= ~SSTATUS_SPIE;
}
return (MATCH_C_NOP);
@@ -556,6 +550,7 @@
kp->kp_patchval = KINST_PATCHVAL;
else
kp->kp_patchval = KINST_C_PATCHVAL;
+ kp->kp_tramp = kinst_trampoline_alloc(M_WAITOK);
kinst_instr_dissect(kp, instrsize);
kinst_probe_create(kp, lf);
@@ -571,14 +566,15 @@
int
kinst_md_init(void)
{
- uint8_t *tramp;
+ struct kinst_cpu_state *ks;
int cpu;
CPU_FOREACH(cpu) {
- tramp = kinst_trampoline_alloc(M_WAITOK);
- if (tramp == NULL)
+ ks = malloc(sizeof(*ks), M_KINST, M_WAITOK | M_ZERO);
+ if (ks == NULL)
return (ENOMEM);
- DPCPU_ID_SET(cpu, intr_tramp, tramp);
+ ks->state = KINST_PROBE_ARMED;
+ DPCPU_ID_SET(cpu, kinst_state, ks);
}
return (0);
@@ -587,14 +583,14 @@
void
kinst_md_deinit(void)
{
- uint8_t *tramp;
+ struct kinst_cpu_state *ks;
int cpu;
CPU_FOREACH(cpu) {
- tramp = DPCPU_ID_GET(cpu, intr_tramp);
- if (tramp != NULL) {
- kinst_trampoline_dealloc(tramp);
- DPCPU_ID_SET(cpu, intr_tramp, NULL);
+ ks = DPCPU_ID_GET(cpu, kinst_state);
+ if (ks != NULL) {
+ free(ks, M_KINST);
+ DPCPU_ID_SET(cpu, kinst_state, NULL);
}
}
}

File Metadata

Mime Type
text/plain
Expires
Mon, Feb 9, 7:41 AM (9 h, 24 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
28554696
Default Alt Text
D40963.id124639.diff (5 KB)

Event Timeline