mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-18 09:58:27 +07:00
533059281e
Replace {k,u}probe event argument fetching framework with switch-case based.
Currently that is implemented with structures, macros and chain of
function-pointers, which is more complicated than necessary and may get a
performance penalty by retpoline.
This simplify that with an array of "fetch_insn" (opcode and oprands), and
make process_fetch_insn() just interprets it. No function pointers are used.
Link: http://lkml.kernel.org/r/152465868340.26224.2551120475197839464.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
121 lines
2.6 KiB
C
121 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Traceprobe fetch helper inlines
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*/
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static nokprobe_inline void
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fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
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{
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switch (code->size) {
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case 1:
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*(u8 *)buf = (u8)val;
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break;
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case 2:
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*(u16 *)buf = (u16)val;
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break;
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case 4:
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*(u32 *)buf = (u32)val;
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break;
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case 8:
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//TBD: 32bit signed
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*(u64 *)buf = (u64)val;
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break;
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default:
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*(unsigned long *)buf = val;
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}
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}
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static nokprobe_inline void
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fetch_apply_bitfield(struct fetch_insn *code, void *buf)
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{
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switch (code->basesize) {
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case 1:
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*(u8 *)buf <<= code->lshift;
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*(u8 *)buf >>= code->rshift;
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break;
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case 2:
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*(u16 *)buf <<= code->lshift;
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*(u16 *)buf >>= code->rshift;
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break;
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case 4:
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*(u32 *)buf <<= code->lshift;
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*(u32 *)buf >>= code->rshift;
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break;
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case 8:
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*(u64 *)buf <<= code->lshift;
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*(u64 *)buf >>= code->rshift;
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break;
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}
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}
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/* Define this for each callsite */
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static int
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process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,
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void *dest, bool pre);
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/* Sum up total data length for dynamic arraies (strings) */
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static nokprobe_inline int
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__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
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{
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struct probe_arg *arg;
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int i, ret = 0;
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u32 len;
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for (i = 0; i < tp->nr_args; i++) {
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arg = tp->args + i;
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if (unlikely(arg->dynamic)) {
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process_fetch_insn(arg->code, regs, &len, true);
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ret += len;
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}
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}
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return ret;
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}
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/* Store the value of each argument */
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static nokprobe_inline void
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store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
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u8 *data, int maxlen)
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{
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struct probe_arg *arg;
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u32 end = tp->size;
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u32 *dl; /* Data (relative) location */
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int i;
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for (i = 0; i < tp->nr_args; i++) {
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arg = tp->args + i;
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if (unlikely(arg->dynamic)) {
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/*
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* First, we set the relative location and
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* maximum data length to *dl
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*/
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dl = (u32 *)(data + arg->offset);
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*dl = make_data_rloc(maxlen, end - arg->offset);
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/* Then try to fetch string or dynamic array data */
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process_fetch_insn(arg->code, regs, dl, false);
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/* Reduce maximum length */
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end += get_rloc_len(*dl);
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maxlen -= get_rloc_len(*dl);
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/* Trick here, convert data_rloc to data_loc */
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*dl = convert_rloc_to_loc(*dl, ent_size + arg->offset);
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} else
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/* Just fetching data normally */
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process_fetch_insn(arg->code, regs, data + arg->offset,
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false);
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}
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}
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static inline int
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print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
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u8 *data, void *field)
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{
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int i;
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for (i = 0; i < nr_args; i++) {
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trace_seq_printf(s, " %s=", args[i].name);
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if (!args[i].type->print(s, data + args[i].offset, field))
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return -ENOMEM;
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}
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return 0;
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}
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