Re: [PATCH v2 07/17] tracing: probeevent: Introduce new argument fetching code

From: Masami Hiramatsu
Date: Fri Feb 23 2018 - 04:43:53 EST

On Fri, 23 Feb 2018 13:30:03 +0900
Namhyung Kim <namhyung@xxxxxxxxxx> wrote:

> On Wed, Feb 21, 2018 at 11:57:36PM +0900, Masami Hiramatsu wrote:
> > 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.
>
> I think it'd be nice to split this commit to 3 parts:
>
> * convert to the fetch_insn
> * remove fetch methods (now unused)

Hmm, I think we can do above 2 parts at a time, because fetch
methods are internal implementation, which is closed among
probe-event.

> * unify fetch type table

Sure. this is an actual cleanup.

Thank you,

>
> Thanks,
> Namhyung
>
>
> >
> > Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > ---
> > Changes in v2:
> > - Allow $comm:string.
> > ---
> > kernel/trace/trace_kprobe.c | 314 +++++++++++-----------------
> > kernel/trace/trace_probe.c | 441 ++++++++++++---------------------------
> > kernel/trace/trace_probe.h | 232 ++++-----------------
> > kernel/trace/trace_probe_tmpl.h | 120 +++++++++++
> > kernel/trace/trace_uprobe.c | 150 +++++++------
> > 5 files changed, 517 insertions(+), 740 deletions(-)
> > create mode 100644 kernel/trace/trace_probe_tmpl.h
> >
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index a96328dfc012..5dd2d470cc7e 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -24,6 +24,7 @@
> > #include <linux/error-injection.h>
> >
> > #include "trace_probe.h"
> > +#include "trace_probe_tmpl.h"
> >
> > #define KPROBE_EVENT_SYSTEM "kprobes"
> > #define KRETPROBE_MAXACTIVE_MAX 4096
> > @@ -121,184 +122,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
> > static int kretprobe_dispatcher(struct kretprobe_instance *ri,
> > struct pt_regs *regs);
> >
> > -/* Memory fetching by symbol */
> > -struct symbol_cache {
> > - char *symbol;
> > - long offset;
> > - unsigned long addr;
> > -};
> > -
> > -unsigned long update_symbol_cache(struct symbol_cache *sc)
> > -{
> > - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
> > -
> > - if (sc->addr)
> > - sc->addr += sc->offset;
> > -
> > - return sc->addr;
> > -}
> > -
> > -void free_symbol_cache(struct symbol_cache *sc)
> > -{
> > - kfree(sc->symbol);
> > - kfree(sc);
> > -}
> > -
> > -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
> > -{
> > - struct symbol_cache *sc;
> > -
> > - if (!sym || strlen(sym) == 0)
> > - return NULL;
> > -
> > - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
> > - if (!sc)
> > - return NULL;
> > -
> > - sc->symbol = kstrdup(sym, GFP_KERNEL);
> > - if (!sc->symbol) {
> > - kfree(sc);
> > - return NULL;
> > - }
> > - sc->offset = offset;
> > - update_symbol_cache(sc);
> > -
> > - return sc;
> > -}
> > -
> > -/*
> > - * Kprobes-specific fetch functions
> > - */
> > -#define DEFINE_FETCH_stack(type) \
> > -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
> > - void *offset, void *dest) \
> > -{ \
> > - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
> > - (unsigned int)((unsigned long)offset)); \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
> > -
> > -DEFINE_BASIC_FETCH_FUNCS(stack)
> > -/* No string on the stack entry */
> > -#define fetch_stack_string NULL
> > -#define fetch_stack_string_size NULL
> > -
> > -#define DEFINE_FETCH_memory(type) \
> > -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
> > - void *addr, void *dest) \
> > -{ \
> > - type retval; \
> > - if (probe_kernel_address(addr, retval)) \
> > - *(type *)dest = 0; \
> > - else \
> > - *(type *)dest = retval; \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
> > -
> > -DEFINE_BASIC_FETCH_FUNCS(memory)
> > -/*
> > - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
> > - * length and relative data location.
> > - */
> > -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
> > - void *addr, void *dest)
> > -{
> > - int maxlen = get_rloc_len(*(u32 *)dest);
> > - u8 *dst = get_rloc_data(dest);
> > - long ret;
> > -
> > - if (!maxlen)
> > - return;
> > -
> > - /*
> > - * Try to get string again, since the string can be changed while
> > - * probing.
> > - */
> > - ret = strncpy_from_unsafe(dst, addr, maxlen);
> > -
> > - if (ret < 0) { /* Failed to fetch string */
> > - dst[0] = '\0';
> > - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
> > - } else {
> > - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
> > - }
> > -}
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
> > -
> > -/* Return the length of string -- including null terminal byte */
> > -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
> > - void *addr, void *dest)
> > -{
> > - mm_segment_t old_fs;
> > - int ret, len = 0;
> > - u8 c;
> > -
> > - old_fs = get_fs();
> > - set_fs(KERNEL_DS);
> > - pagefault_disable();
> > -
> > - do {
> > - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
> > - len++;
> > - } while (c && ret == 0 && len < MAX_STRING_SIZE);
> > -
> > - pagefault_enable();
> > - set_fs(old_fs);
> > -
> > - if (ret < 0) /* Failed to check the length */
> > - *(u32 *)dest = 0;
> > - else
> > - *(u32 *)dest = len;
> > -}
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
> > -
> > -#define DEFINE_FETCH_symbol(type) \
> > -void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
> > -{ \
> > - struct symbol_cache *sc = data; \
> > - if (sc->addr) \
> > - fetch_memory_##type(regs, (void *)sc->addr, dest); \
> > - else \
> > - *(type *)dest = 0; \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
> > -
> > -DEFINE_BASIC_FETCH_FUNCS(symbol)
> > -DEFINE_FETCH_symbol(string)
> > -DEFINE_FETCH_symbol(string_size)
> > -
> > -/* kprobes don't support file_offset fetch methods */
> > -#define fetch_file_offset_u8 NULL
> > -#define fetch_file_offset_u16 NULL
> > -#define fetch_file_offset_u32 NULL
> > -#define fetch_file_offset_u64 NULL
> > -#define fetch_file_offset_string NULL
> > -#define fetch_file_offset_string_size NULL
> > -
> > -/* Fetch type information table */
> > -static const struct fetch_type kprobes_fetch_type_table[] = {
> > - /* Special types */
> > - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
> > - sizeof(u32), 1, "__data_loc char[]"),
> > - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
> > - string_size, sizeof(u32), 0, "u32"),
> > - /* Basic types */
> > - ASSIGN_FETCH_TYPE(u8, u8, 0),
> > - ASSIGN_FETCH_TYPE(u16, u16, 0),
> > - ASSIGN_FETCH_TYPE(u32, u32, 0),
> > - ASSIGN_FETCH_TYPE(u64, u64, 0),
> > - ASSIGN_FETCH_TYPE(s8, u8, 1),
> > - ASSIGN_FETCH_TYPE(s16, u16, 1),
> > - ASSIGN_FETCH_TYPE(s32, u32, 1),
> > - ASSIGN_FETCH_TYPE(s64, u64, 1),
> > - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
> > -
> > - ASSIGN_FETCH_TYPE_END
> > -};
> > -
> > /*
> > * Allocate new trace_probe and initialize it (including kprobes).
> > */
> > @@ -490,14 +313,11 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
> > /* Internal register function - just handle k*probes and flags */
> > static int __register_trace_kprobe(struct trace_kprobe *tk)
> > {
> > - int i, ret;
> > + int ret;
> >
> > if (trace_probe_is_registered(&tk->tp))
> > return -EINVAL;
> >
> > - for (i = 0; i < tk->tp.nr_args; i++)
> > - traceprobe_update_arg(&tk->tp.args[i]);
> > -
> > /* Set/clear disabled flag according to tp->flag */
> > if (trace_probe_is_enabled(&tk->tp))
> > tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
> > @@ -830,8 +650,7 @@ static int create_trace_kprobe(int argc, char **argv)
> >
> > /* Parse fetch argument */
> > ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
> > - is_return, true,
> > - kprobes_fetch_type_table);
> > + is_return, true);
> > if (ret) {
> > pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
> > goto error;
> > @@ -985,6 +804,133 @@ static const struct file_operations kprobe_profile_ops = {
> > .release = seq_release,
> > };
> >
> > +/* Kprobe specific fetch functions */
> > +
> > +/* Return the length of string -- including null terminal byte */
> > +static nokprobe_inline void
> > +fetch_store_strlen(unsigned long addr, void *dest)
> > +{
> > + mm_segment_t old_fs;
> > + int ret, len = 0;
> > + u8 c;
> > +
> > + old_fs = get_fs();
> > + set_fs(KERNEL_DS);
> > + pagefault_disable();
> > +
> > + do {
> > + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
> > + len++;
> > + } while (c && ret == 0 && len < MAX_STRING_SIZE);
> > +
> > + pagefault_enable();
> > + set_fs(old_fs);
> > +
> > + if (ret < 0) /* Failed to check the length */
> > + *(u32 *)dest = 0;
> > + else
> > + *(u32 *)dest = len;
> > +}
> > +
> > +/*
> > + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
> > + * length and relative data location.
> > + */
> > +static nokprobe_inline void
> > +fetch_store_string(unsigned long addr, void *dest)
> > +{
> > + int maxlen = get_rloc_len(*(u32 *)dest);
> > + u8 *dst = get_rloc_data(dest);
> > + long ret;
> > +
> > + if (!maxlen)
> > + return;
> > +
> > + /*
> > + * Try to get string again, since the string can be changed while
> > + * probing.
> > + */
> > + ret = strncpy_from_unsafe(dst, (void *)addr, maxlen);
> > +
> > + if (ret < 0) { /* Failed to fetch string */
> > + dst[0] = '\0';
> > + *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
> > + } else {
> > + *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
> > + }
> > +}
> > +
> > +/* Note that we don't verify it, since the code does not come from user space */
> > +static int
> > +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
> > + bool pre)
> > +{
> > + unsigned long val;
> > + int ret;
> > +
> > + /* 1st stage: get value from context */
> > + switch (code->op) {
> > + case FETCH_OP_REG:
> > + val = regs_get_register(regs, code->param);
> > + break;
> > + case FETCH_OP_STACK:
> > + val = regs_get_kernel_stack_nth(regs, code->param);
> > + break;
> > + case FETCH_OP_STACKP:
> > + val = kernel_stack_pointer(regs);
> > + break;
> > + case FETCH_OP_RETVAL:
> > + val = regs_return_value(regs);
> > + break;
> > + case FETCH_OP_IMM:
> > + val = code->immediate;
> > + break;
> > + case FETCH_OP_COMM:
> > + val = (unsigned long)current->comm;
> > + break;
> > + default:
> > + return -EILSEQ;
> > + }
> > + code++;
> > +
> > + /* 2nd stage: dereference memory if needed */
> > + while (code->op == FETCH_OP_DEREF) {
> > + ret = probe_kernel_read(&val, (void *)val + code->offset,
> > + sizeof(val));
> > + if (ret)
> > + return ret;
> > + code++;
> > + }
> > +
> > + /* 3rd stage: store value to buffer */
> > + switch (code->op) {
> > + case FETCH_OP_ST_RAW:
> > + fetch_store_raw(val, code, dest);
> > + break;
> > + case FETCH_OP_ST_MEM:
> > + probe_kernel_read(dest, (void *)val + code->offset, code->size);
> > + break;
> > + case FETCH_OP_ST_STRING:
> > + if (pre)
> > + fetch_store_strlen(val + code->offset, dest);
> > + else
> > + fetch_store_string(val + code->offset, dest);
> > + break;
> > + default:
> > + return -EILSEQ;
> > + }
> > + code++;
> > +
> > + /* 4th stage: modify stored value if needed */
> > + if (code->op == FETCH_OP_MOD_BF) {
> > + fetch_apply_bitfield(code, dest);
> > + code++;
> > + }
> > +
> > + return code->op == FETCH_OP_END ? 0 : -EILSEQ;
> > +}
> > +NOKPROBE_SYMBOL(process_fetch_insn)
> > +
> > /* Kprobe handler */
> > static nokprobe_inline void
> > __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
> > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> > index 37bdd56b4988..cd87490b3492 100644
> > --- a/kernel/trace/trace_probe.c
> > +++ b/kernel/trace/trace_probe.c
> > @@ -73,176 +73,29 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
> >
> > const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
> >
> > -#define CHECK_FETCH_FUNCS(method, fn) \
> > - (((FETCH_FUNC_NAME(method, u8) == fn) || \
> > - (FETCH_FUNC_NAME(method, u16) == fn) || \
> > - (FETCH_FUNC_NAME(method, u32) == fn) || \
> > - (FETCH_FUNC_NAME(method, u64) == fn) || \
> > - (FETCH_FUNC_NAME(method, string) == fn) || \
> > - (FETCH_FUNC_NAME(method, string_size) == fn)) \
> > - && (fn != NULL))
> > -
> > -/* Data fetch function templates */
> > -#define DEFINE_FETCH_reg(type) \
> > -void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \
> > -{ \
> > - *(type *)dest = (type)regs_get_register(regs, \
> > - (unsigned int)((unsigned long)offset)); \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
> > -DEFINE_BASIC_FETCH_FUNCS(reg)
> > -/* No string on the register */
> > -#define fetch_reg_string NULL
> > -#define fetch_reg_string_size NULL
> > -
> > -#define DEFINE_FETCH_retval(type) \
> > -void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
> > - void *dummy, void *dest) \
> > -{ \
> > - *(type *)dest = (type)regs_return_value(regs); \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
> > -DEFINE_BASIC_FETCH_FUNCS(retval)
> > -/* No string on the retval */
> > -#define fetch_retval_string NULL
> > -#define fetch_retval_string_size NULL
> > -
> > -/* Dereference memory access function */
> > -struct deref_fetch_param {
> > - struct fetch_param orig;
> > - long offset;
> > - fetch_func_t fetch;
> > - fetch_func_t fetch_size;
> > -};
> > -
> > -#define DEFINE_FETCH_deref(type) \
> > -void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
> > - void *data, void *dest) \
> > -{ \
> > - struct deref_fetch_param *dprm = data; \
> > - unsigned long addr; \
> > - call_fetch(&dprm->orig, regs, &addr); \
> > - if (addr) { \
> > - addr += dprm->offset; \
> > - dprm->fetch(regs, (void *)addr, dest); \
> > - } else \
> > - *(type *)dest = 0; \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
> > -DEFINE_BASIC_FETCH_FUNCS(deref)
> > -DEFINE_FETCH_deref(string)
> > -
> > -void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
> > - void *data, void *dest)
> > -{
> > - struct deref_fetch_param *dprm = data;
> > - unsigned long addr;
> > -
> > - call_fetch(&dprm->orig, regs, &addr);
> > - if (addr && dprm->fetch_size) {
> > - addr += dprm->offset;
> > - dprm->fetch_size(regs, (void *)addr, dest);
> > - } else
> > - *(string_size *)dest = 0;
> > -}
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
> > -
> > -static void update_deref_fetch_param(struct deref_fetch_param *data)
> > -{
> > - if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
> > - update_deref_fetch_param(data->orig.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
> > - update_symbol_cache(data->orig.data);
> > -}
> > -NOKPROBE_SYMBOL(update_deref_fetch_param);
> > -
> > -static void free_deref_fetch_param(struct deref_fetch_param *data)
> > -{
> > - if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
> > - free_deref_fetch_param(data->orig.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
> > - free_symbol_cache(data->orig.data);
> > - kfree(data);
> > -}
> > -NOKPROBE_SYMBOL(free_deref_fetch_param);
> > -
> > -/* Bitfield fetch function */
> > -struct bitfield_fetch_param {
> > - struct fetch_param orig;
> > - unsigned char hi_shift;
> > - unsigned char low_shift;
> > +/* Fetch type information table */
> > +static const struct fetch_type probe_fetch_types[] = {
> > + /* Special types */
> > + __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,
> > + "__data_loc char[]"),
> > + /* Basic types */
> > + ASSIGN_FETCH_TYPE(u8, u8, 0),
> > + ASSIGN_FETCH_TYPE(u16, u16, 0),
> > + ASSIGN_FETCH_TYPE(u32, u32, 0),
> > + ASSIGN_FETCH_TYPE(u64, u64, 0),
> > + ASSIGN_FETCH_TYPE(s8, u8, 1),
> > + ASSIGN_FETCH_TYPE(s16, u16, 1),
> > + ASSIGN_FETCH_TYPE(s32, u32, 1),
> > + ASSIGN_FETCH_TYPE(s64, u64, 1),
> > + ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
> > + ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
> > + ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
> > + ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
> > +
> > + ASSIGN_FETCH_TYPE_END
> > };
> >
> > -#define DEFINE_FETCH_bitfield(type) \
> > -void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
> > - void *data, void *dest) \
> > -{ \
> > - struct bitfield_fetch_param *bprm = data; \
> > - type buf = 0; \
> > - call_fetch(&bprm->orig, regs, &buf); \
> > - if (buf) { \
> > - buf <<= bprm->hi_shift; \
> > - buf >>= bprm->low_shift; \
> > - } \
> > - *(type *)dest = buf; \
> > -} \
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
> > -DEFINE_BASIC_FETCH_FUNCS(bitfield)
> > -#define fetch_bitfield_string NULL
> > -#define fetch_bitfield_string_size NULL
> > -
> > -static void
> > -update_bitfield_fetch_param(struct bitfield_fetch_param *data)
> > -{
> > - /*
> > - * Don't check the bitfield itself, because this must be the
> > - * last fetch function.
> > - */
> > - if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
> > - update_deref_fetch_param(data->orig.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
> > - update_symbol_cache(data->orig.data);
> > -}
> > -
> > -static void
> > -free_bitfield_fetch_param(struct bitfield_fetch_param *data)
> > -{
> > - /*
> > - * Don't check the bitfield itself, because this must be the
> > - * last fetch function.
> > - */
> > - if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
> > - free_deref_fetch_param(data->orig.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
> > - free_symbol_cache(data->orig.data);
> > -
> > - kfree(data);
> > -}
> > -
> > -void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,
> > - void *data, void *dest)
> > -{
> > - int maxlen = get_rloc_len(*(u32 *)dest);
> > - u8 *dst = get_rloc_data(dest);
> > - long ret;
> > -
> > - if (!maxlen)
> > - return;
> > -
> > - ret = strlcpy(dst, current->comm, maxlen);
> > - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
> > -}
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));
> > -
> > -void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,
> > - void *data, void *dest)
> > -{
> > - *(u32 *)dest = strlen(current->comm) + 1;
> > -}
> > -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));
> > -
> > -static const struct fetch_type *find_fetch_type(const char *type,
> > - const struct fetch_type *ftbl)
> > +static const struct fetch_type *find_fetch_type(const char *type)
> > {
> > int i;
> >
> > @@ -263,58 +116,27 @@ static const struct fetch_type *find_fetch_type(const char *type,
> >
> > switch (bs) {
> > case 8:
> > - return find_fetch_type("u8", ftbl);
> > + return find_fetch_type("u8");
> > case 16:
> > - return find_fetch_type("u16", ftbl);
> > + return find_fetch_type("u16");
> > case 32:
> > - return find_fetch_type("u32", ftbl);
> > + return find_fetch_type("u32");
> > case 64:
> > - return find_fetch_type("u64", ftbl);
> > + return find_fetch_type("u64");
> > default:
> > goto fail;
> > }
> > }
> >
> > - for (i = 0; ftbl[i].name; i++) {
> > - if (strcmp(type, ftbl[i].name) == 0)
> > - return &ftbl[i];
> > + for (i = 0; probe_fetch_types[i].name; i++) {
> > + if (strcmp(type, probe_fetch_types[i].name) == 0)
> > + return &probe_fetch_types[i];
> > }
> >
> > fail:
> > return NULL;
> > }
> >
> > -/* Special function : only accept unsigned long */
> > -static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest)
> > -{
> > - *(unsigned long *)dest = kernel_stack_pointer(regs);
> > -}
> > -NOKPROBE_SYMBOL(fetch_kernel_stack_address);
> > -
> > -static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest)
> > -{
> > - *(unsigned long *)dest = user_stack_pointer(regs);
> > -}
> > -NOKPROBE_SYMBOL(fetch_user_stack_address);
> > -
> > -static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
> > - fetch_func_t orig_fn,
> > - const struct fetch_type *ftbl)
> > -{
> > - int i;
> > -
> > - if (type != &ftbl[FETCH_TYPE_STRING])
> > - return NULL; /* Only string type needs size function */
> > -
> > - for (i = 0; i < FETCH_MTD_END; i++)
> > - if (type->fetch[i] == orig_fn)
> > - return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
> > -
> > - WARN_ON(1); /* This should not happen */
> > -
> > - return NULL;
> > -}
> > -
> > /* Split symbol and offset. */
> > int traceprobe_split_symbol_offset(char *symbol, long *offset)
> > {
> > @@ -341,7 +163,7 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset)
> > #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
> >
> > static int parse_probe_vars(char *arg, const struct fetch_type *t,
> > - struct fetch_param *f, bool is_return,
> > + struct fetch_insn *code, bool is_return,
> > bool is_kprobe)
> > {
> > int ret = 0;
> > @@ -349,33 +171,24 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
> >
> > if (strcmp(arg, "retval") == 0) {
> > if (is_return)
> > - f->fn = t->fetch[FETCH_MTD_retval];
> > + code->op = FETCH_OP_RETVAL;
> > else
> > ret = -EINVAL;
> > } else if (strncmp(arg, "stack", 5) == 0) {
> > if (arg[5] == '\0') {
> > - if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
> > - return -EINVAL;
> > -
> > - if (is_kprobe)
> > - f->fn = fetch_kernel_stack_address;
> > - else
> > - f->fn = fetch_user_stack_address;
> > + code->op = FETCH_OP_STACKP;
> > } else if (isdigit(arg[5])) {
> > ret = kstrtoul(arg + 5, 10, &param);
> > if (ret || (is_kprobe && param > PARAM_MAX_STACK))
> > ret = -EINVAL;
> > else {
> > - f->fn = t->fetch[FETCH_MTD_stack];
> > - f->data = (void *)param;
> > + code->op = FETCH_OP_STACK;
> > + code->param = (unsigned int)param;
> > }
> > } else
> > ret = -EINVAL;
> > } else if (strcmp(arg, "comm") == 0) {
> > - if (strcmp(t->name, "string") != 0 &&
> > - strcmp(t->name, "string_size") != 0)
> > - return -EINVAL;
> > - f->fn = t->fetch[FETCH_MTD_comm];
> > + code->op = FETCH_OP_COMM;
> > } else
> > ret = -EINVAL;
> >
> > @@ -383,10 +196,12 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
> > }
> >
> > /* Recursive argument parser */
> > -static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > - struct fetch_param *f, bool is_return, bool is_kprobe,
> > - const struct fetch_type *ftbl)
> > +static int
> > +parse_probe_arg(char *arg, const struct fetch_type *type,
> > + struct fetch_insn **pcode, struct fetch_insn *end,
> > + bool is_return, bool is_kprobe)
> > {
> > + struct fetch_insn *code = *pcode;
> > unsigned long param;
> > long offset;
> > char *tmp;
> > @@ -394,14 +209,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> >
> > switch (arg[0]) {
> > case '$':
> > - ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
> > + ret = parse_probe_vars(arg + 1, type, code,
> > + is_return, is_kprobe);
> > break;
> >
> > case '%': /* named register */
> > ret = regs_query_register_offset(arg + 1);
> > if (ret >= 0) {
> > - f->fn = t->fetch[FETCH_MTD_reg];
> > - f->data = (void *)(unsigned long)ret;
> > + code->op = FETCH_OP_REG;
> > + code->param = (unsigned int)ret;
> > ret = 0;
> > }
> > break;
> > @@ -411,9 +227,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > ret = kstrtoul(arg + 1, 0, &param);
> > if (ret)
> > break;
> > -
> > - f->fn = t->fetch[FETCH_MTD_memory];
> > - f->data = (void *)param;
> > + /* load address */
> > + code->op = FETCH_OP_IMM;
> > + code->immediate = param;
> > } else if (arg[1] == '+') {
> > /* kprobes don't support file offsets */
> > if (is_kprobe)
> > @@ -423,8 +239,8 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > if (ret)
> > break;
> >
> > - f->fn = t->fetch[FETCH_MTD_file_offset];
> > - f->data = (void *)offset;
> > + code->op = FETCH_OP_FOFFS;
> > + code->immediate = (unsigned long)offset; // imm64?
> > } else {
> > /* uprobes don't support symbols */
> > if (!is_kprobe)
> > @@ -434,10 +250,19 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > if (ret)
> > break;
> >
> > - f->data = alloc_symbol_cache(arg + 1, offset);
> > - if (f->data)
> > - f->fn = t->fetch[FETCH_MTD_symbol];
> > + code->op = FETCH_OP_IMM;
> > + code->immediate =
> > + (unsigned long)kallsyms_lookup_name(arg + 1);
> > + if (!code->immediate)
> > + return -ENOENT;
> > + code->immediate += offset;
> > }
> > + /* These are fetching from memory */
> > + if (++code == end)
> > + return -E2BIG;
> > + *pcode = code;
> > + code->op = FETCH_OP_DEREF;
> > + code->offset = offset;
> > break;
> >
> > case '+': /* deref memory */
> > @@ -445,11 +270,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > case '-':
> > tmp = strchr(arg, '(');
> > if (!tmp)
> > - break;
> > + return -EINVAL;
> >
> > *tmp = '\0';
> > ret = kstrtol(arg, 0, &offset);
> > -
> > if (ret)
> > break;
> >
> > @@ -457,36 +281,28 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > tmp = strrchr(arg, ')');
> >
> > if (tmp) {
> > - struct deref_fetch_param *dprm;
> > - const struct fetch_type *t2;
> > + const struct fetch_type *t2 = find_fetch_type(NULL);
> >
> > - t2 = find_fetch_type(NULL, ftbl);
> > *tmp = '\0';
> > - dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
> > -
> > - if (!dprm)
> > - return -ENOMEM;
> > -
> > - dprm->offset = offset;
> > - dprm->fetch = t->fetch[FETCH_MTD_memory];
> > - dprm->fetch_size = get_fetch_size_function(t,
> > - dprm->fetch, ftbl);
> > - ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
> > - is_kprobe, ftbl);
> > + ret = parse_probe_arg(arg, t2, &code, end, is_return,
> > + is_kprobe);
> > if (ret)
> > - kfree(dprm);
> > - else {
> > - f->fn = t->fetch[FETCH_MTD_deref];
> > - f->data = (void *)dprm;
> > - }
> > + break;
> > + if (code->op == FETCH_OP_COMM)
> > + return -EINVAL;
> > + if (++code == end)
> > + return -E2BIG;
> > + *pcode = code;
> > +
> > + code->op = FETCH_OP_DEREF;
> > + code->offset = offset;
> > }
> > break;
> > }
> > - if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
> > - pr_info("%s type has no corresponding fetch method.\n", t->name);
> > + if (!ret && code->op == FETCH_OP_NOP) {
> > + /* Parsed, but do not find fetch method */
> > ret = -EINVAL;
> > }
> > -
> > return ret;
> > }
> >
> > @@ -495,22 +311,15 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> > /* Bitfield type needs to be parsed into a fetch function */
> > static int __parse_bitfield_probe_arg(const char *bf,
> > const struct fetch_type *t,
> > - struct fetch_param *f)
> > + struct fetch_insn **pcode)
> > {
> > - struct bitfield_fetch_param *bprm;
> > + struct fetch_insn *code = *pcode;
> > unsigned long bw, bo;
> > char *tail;
> >
> > if (*bf != 'b')
> > return 0;
> >
> > - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
> > - if (!bprm)
> > - return -ENOMEM;
> > -
> > - bprm->orig = *f;
> > - f->fn = t->fetch[FETCH_MTD_bitfield];
> > - f->data = (void *)bprm;
> > bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
> >
> > if (bw == 0 || *tail != '@')
> > @@ -521,18 +330,24 @@ static int __parse_bitfield_probe_arg(const char *bf,
> >
> > if (tail == bf || *tail != '/')
> > return -EINVAL;
> > + code++;
> > + if (code->op != FETCH_OP_NOP)
> > + return -E2BIG;
> > + *pcode = code;
> >
> > - bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
> > - bprm->low_shift = bprm->hi_shift + bo;
> > + code->op = FETCH_OP_MOD_BF;
> > + code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
> > + code->rshift = BYTES_TO_BITS(t->size) - bw;
> > + code->basesize = t->size;
> >
> > return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
> > }
> >
> > /* String length checking wrapper */
> > int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> > - struct probe_arg *parg, bool is_return, bool is_kprobe,
> > - const struct fetch_type *ftbl)
> > + struct probe_arg *parg, bool is_return, bool is_kprobe)
> > {
> > + struct fetch_insn *code, *tmp = NULL;
> > const char *t;
> > int ret;
> >
> > @@ -556,25 +371,67 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> > */
> > if (!t && strcmp(arg, "$comm") == 0)
> > t = "string";
> > - parg->type = find_fetch_type(t, ftbl);
> > + parg->type = find_fetch_type(t);
> > if (!parg->type) {
> > pr_info("Unsupported type: %s\n", t);
> > return -EINVAL;
> > }
> > parg->offset = *size;
> > *size += parg->type->size;
> > - ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
> > - is_kprobe, ftbl);
> > -
> > - if (ret >= 0 && t != NULL)
> > - ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
> >
> > - if (ret >= 0) {
> > - parg->fetch_size.fn = get_fetch_size_function(parg->type,
> > - parg->fetch.fn,
> > - ftbl);
> > - parg->fetch_size.data = parg->fetch.data;
> > + code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL);
> > + if (!code)
> > + return -ENOMEM;
> > + code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
> > +
> > + ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
> > + is_return, is_kprobe);
> > + if (ret)
> > + goto fail;
> > +
> > + /* Store operation */
> > + if (!strcmp(parg->type->name, "string")) {
> > + if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
> > + code->op != FETCH_OP_COMM) {
> > + pr_info("string only accepts memory or address.\n");
> > + ret = -EINVAL;
> > + goto fail;
> > + }
> > + /* Since IMM or COMM must be the 1st insn, this is safe */
> > + if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM)
> > + code++;
> > + code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
> > + parg->dynamic = true;
> > + } else if (code->op == FETCH_OP_DEREF) {
> > + code->op = FETCH_OP_ST_MEM;
> > + code->size = parg->type->size;
> > + } else {
> > + code++;
> > + if (code->op != FETCH_OP_NOP) {
> > + ret = -E2BIG;
> > + goto fail;
> > + }
> > + code->op = FETCH_OP_ST_RAW;
> > + code->size = parg->type->size;
> > }
> > + /* Modify operation */
> > + if (t != NULL) {
> > + ret = __parse_bitfield_probe_arg(t, parg->type, &code);
> > + if (ret)
> > + goto fail;
> > + }
> > + code++;
> > + code->op = FETCH_OP_END;
> > +
> > + /* Shrink down the code buffer */
> > + parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL);
> > + if (!parg->code)
> > + ret = -ENOMEM;
> > + else
> > + memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
> > +
> > +fail:
> > + kfree(tmp);
> >
> > return ret;
> > }
> > @@ -596,25 +453,9 @@ int traceprobe_conflict_field_name(const char *name,
> > return 0;
> > }
> >
> > -void traceprobe_update_arg(struct probe_arg *arg)
> > -{
> > - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
> > - update_bitfield_fetch_param(arg->fetch.data);
> > - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
> > - update_deref_fetch_param(arg->fetch.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
> > - update_symbol_cache(arg->fetch.data);
> > -}
> > -
> > void traceprobe_free_probe_arg(struct probe_arg *arg)
> > {
> > - if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
> > - free_bitfield_fetch_param(arg->fetch.data);
> > - else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
> > - free_deref_fetch_param(arg->fetch.data);
> > - else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
> > - free_symbol_cache(arg->fetch.data);
> > -
> > + kfree(arg->code);
> > kfree(arg->name);
> > kfree(arg->comm);
> > }
> > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> > index de928052926b..89d853ef5174 100644
> > --- a/kernel/trace/trace_probe.h
> > +++ b/kernel/trace/trace_probe.h
> > @@ -91,25 +91,50 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
> > return (u8 *)ent + get_rloc_offs(*dl);
> > }
> >
> > -/* Data fetch function type */
> > -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
> > /* Printing function type */
> > typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
> >
> > -/* Fetch types */
> > -enum {
> > - FETCH_MTD_reg = 0,
> > - FETCH_MTD_stack,
> > - FETCH_MTD_retval,
> > - FETCH_MTD_comm,
> > - FETCH_MTD_memory,
> > - FETCH_MTD_symbol,
> > - FETCH_MTD_deref,
> > - FETCH_MTD_bitfield,
> > - FETCH_MTD_file_offset,
> > - FETCH_MTD_END,
> > +enum fetch_op {
> > + FETCH_OP_NOP = 0,
> > + // Stage 1 (load) ops
> > + FETCH_OP_REG, /* Register : .param = offset */
> > + FETCH_OP_STACK, /* Stack : .param = index */
> > + FETCH_OP_STACKP, /* Stack pointer */
> > + FETCH_OP_RETVAL, /* Return value */
> > + FETCH_OP_IMM, /* Immediate : .immediate */
> > + FETCH_OP_COMM, /* Current comm */
> > + FETCH_OP_FOFFS, /* File offset: .immediate */
> > + // Stage 2 (dereference) op
> > + FETCH_OP_DEREF, /* Dereference: .offset */
> > + // Stage 3 (store) ops
> > + FETCH_OP_ST_RAW, /* Raw: .size */
> > + FETCH_OP_ST_MEM, /* Mem: .offset, .size */
> > + FETCH_OP_ST_STRING, /* String: .offset, .size */
> > + // Stage 4 (modify) op
> > + FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
> > + FETCH_OP_END,
> > };
> >
> > +struct fetch_insn {
> > + enum fetch_op op;
> > + union {
> > + unsigned int param;
> > + struct {
> > + unsigned int size;
> > + int offset;
> > + };
> > + struct {
> > + unsigned char basesize;
> > + unsigned char lshift;
> > + unsigned char rshift;
> > + };
> > + unsigned long immediate;
> > + };
> > +};
> > +
> > +/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
> > +#define FETCH_INSN_MAX 16
> > +
> > /* Fetch type information table */
> > struct fetch_type {
> > const char *name; /* Name of type */
> > @@ -118,13 +143,6 @@ struct fetch_type {
> > print_type_func_t print; /* Print functions */
> > const char *fmt; /* Fromat string */
> > const char *fmttype; /* Name in format file */
> > - /* Fetch functions */
> > - fetch_func_t fetch[FETCH_MTD_END];
> > -};
> > -
> > -struct fetch_param {
> > - fetch_func_t fn;
> > - void *data;
> > };
> >
> > /* For defining macros, define string/string_size types */
> > @@ -154,66 +172,12 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
> >
> > DECLARE_BASIC_PRINT_TYPE_FUNC(string);
> >
> > -#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
> > -
> > -/* Declare macro for basic types */
> > -#define DECLARE_FETCH_FUNC(method, type) \
> > -extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \
> > - void *data, void *dest)
> > -
> > -#define DECLARE_BASIC_FETCH_FUNCS(method) \
> > -DECLARE_FETCH_FUNC(method, u8); \
> > -DECLARE_FETCH_FUNC(method, u16); \
> > -DECLARE_FETCH_FUNC(method, u32); \
> > -DECLARE_FETCH_FUNC(method, u64)
> > -
> > -DECLARE_BASIC_FETCH_FUNCS(reg);
> > -#define fetch_reg_string NULL
> > -#define fetch_reg_string_size NULL
> > -
> > -DECLARE_BASIC_FETCH_FUNCS(retval);
> > -#define fetch_retval_string NULL
> > -#define fetch_retval_string_size NULL
> > -
> > -DECLARE_BASIC_FETCH_FUNCS(symbol);
> > -DECLARE_FETCH_FUNC(symbol, string);
> > -DECLARE_FETCH_FUNC(symbol, string_size);
> > -
> > -DECLARE_BASIC_FETCH_FUNCS(deref);
> > -DECLARE_FETCH_FUNC(deref, string);
> > -DECLARE_FETCH_FUNC(deref, string_size);
> > -
> > -DECLARE_BASIC_FETCH_FUNCS(bitfield);
> > -#define fetch_bitfield_string NULL
> > -#define fetch_bitfield_string_size NULL
> > -
> > -/* comm only makes sense as a string */
> > -#define fetch_comm_u8 NULL
> > -#define fetch_comm_u16 NULL
> > -#define fetch_comm_u32 NULL
> > -#define fetch_comm_u64 NULL
> > -DECLARE_FETCH_FUNC(comm, string);
> > -DECLARE_FETCH_FUNC(comm, string_size);
> > -
> > -/*
> > - * Define macro for basic types - we don't need to define s* types, because
> > - * we have to care only about bitwidth at recording time.
> > - */
> > -#define DEFINE_BASIC_FETCH_FUNCS(method) \
> > -DEFINE_FETCH_##method(u8) \
> > -DEFINE_FETCH_##method(u16) \
> > -DEFINE_FETCH_##method(u32) \
> > -DEFINE_FETCH_##method(u64)
> > -
> > /* Default (unsigned long) fetch type */
> > #define __DEFAULT_FETCH_TYPE(t) x##t
> > #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
> > #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
> > #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
> >
> > -#define ASSIGN_FETCH_FUNC(method, type) \
> > - [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
> > -
> > #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
> > {.name = _name, \
> > .size = _size, \
> > @@ -221,17 +185,6 @@ DEFINE_FETCH_##method(u64)
> > .print = PRINT_TYPE_FUNC_NAME(ptype), \
> > .fmt = PRINT_TYPE_FMT_NAME(ptype), \
> > .fmttype = _fmttype, \
> > - .fetch = { \
> > -ASSIGN_FETCH_FUNC(reg, ftype), \
> > -ASSIGN_FETCH_FUNC(stack, ftype), \
> > -ASSIGN_FETCH_FUNC(retval, ftype), \
> > -ASSIGN_FETCH_FUNC(comm, ftype), \
> > -ASSIGN_FETCH_FUNC(memory, ftype), \
> > -ASSIGN_FETCH_FUNC(symbol, ftype), \
> > -ASSIGN_FETCH_FUNC(deref, ftype), \
> > -ASSIGN_FETCH_FUNC(bitfield, ftype), \
> > -ASSIGN_FETCH_FUNC(file_offset, ftype), \
> > - } \
> > }
> >
> > #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
> > @@ -243,42 +196,10 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \
> >
> > #define ASSIGN_FETCH_TYPE_END {}
> >
> > -#define FETCH_TYPE_STRING 0
> > -#define FETCH_TYPE_STRSIZE 1
> > -
> > #ifdef CONFIG_KPROBE_EVENTS
> > -struct symbol_cache;
> > -unsigned long update_symbol_cache(struct symbol_cache *sc);
> > -void free_symbol_cache(struct symbol_cache *sc);
> > -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
> > bool trace_kprobe_on_func_entry(struct trace_event_call *call);
> > bool trace_kprobe_error_injectable(struct trace_event_call *call);
> > #else
> > -/* uprobes do not support symbol fetch methods */
> > -#define fetch_symbol_u8 NULL
> > -#define fetch_symbol_u16 NULL
> > -#define fetch_symbol_u32 NULL
> > -#define fetch_symbol_u64 NULL
> > -#define fetch_symbol_string NULL
> > -#define fetch_symbol_string_size NULL
> > -
> > -struct symbol_cache {
> > -};
> > -static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
> > -{
> > - return 0;
> > -}
> > -
> > -static inline void __used free_symbol_cache(struct symbol_cache *sc)
> > -{
> > -}
> > -
> > -static inline struct symbol_cache * __used
> > -alloc_symbol_cache(const char *sym, long offset)
> > -{
> > - return NULL;
> > -}
> > -
> > static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
> > {
> > return false;
> > @@ -291,8 +212,8 @@ static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
> > #endif /* CONFIG_KPROBE_EVENTS */
> >
> > struct probe_arg {
> > - struct fetch_param fetch;
> > - struct fetch_param fetch_size;
> > + struct fetch_insn *code;
> > + bool dynamic;/* Dynamic array (string) is used */
> > unsigned int offset; /* Offset from argument entry */
> > const char *name; /* Name of this argument */
> > const char *comm; /* Command of this argument */
> > @@ -324,12 +245,6 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp)
> > return !!(tp->flags & TP_FLAG_REGISTERED);
> > }
> >
> > -static nokprobe_inline void call_fetch(struct fetch_param *fprm,
> > - struct pt_regs *regs, void *dest)
> > -{
> > - return fprm->fn(regs, fprm->data, dest);
> > -}
> > -
> > /* Check the name is good for event/group/fields */
> > static inline bool is_good_name(const char *name)
> > {
> > @@ -355,8 +270,7 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
> > }
> >
> > extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
> > - struct probe_arg *parg, bool is_return, bool is_kprobe,
> > - const struct fetch_type *ftbl);
> > + struct probe_arg *parg, bool is_return, bool is_kprobe);
> >
> > extern int traceprobe_conflict_field_name(const char *name,
> > struct probe_arg *args, int narg);
> > @@ -366,68 +280,6 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg);
> >
> > extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
> >
> > -/* Sum up total data length for dynamic arraies (strings) */
> > -static nokprobe_inline int
> > -__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
> > -{
> > - int i, ret = 0;
> > - u32 len;
> > -
> > - for (i = 0; i < tp->nr_args; i++)
> > - if (unlikely(tp->args[i].fetch_size.fn)) {
> > - call_fetch(&tp->args[i].fetch_size, regs, &len);
> > - ret += len;
> > - }
> > -
> > - return ret;
> > -}
> > -
> > -/* Store the value of each argument */
> > -static nokprobe_inline void
> > -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
> > - u8 *data, int maxlen)
> > -{
> > - int i;
> > - u32 end = tp->size;
> > - u32 *dl; /* Data (relative) location */
> > -
> > - for (i = 0; i < tp->nr_args; i++) {
> > - if (unlikely(tp->args[i].fetch_size.fn)) {
> > - /*
> > - * First, we set the relative location and
> > - * maximum data length to *dl
> > - */
> > - dl = (u32 *)(data + tp->args[i].offset);
> > - *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
> > - /* Then try to fetch string or dynamic array data */
> > - call_fetch(&tp->args[i].fetch, regs, dl);
> > - /* Reduce maximum length */
> > - end += get_rloc_len(*dl);
> > - maxlen -= get_rloc_len(*dl);
> > - /* Trick here, convert data_rloc to data_loc */
> > - *dl = convert_rloc_to_loc(*dl,
> > - ent_size + tp->args[i].offset);
> > - } else
> > - /* Just fetching data normally */
> > - call_fetch(&tp->args[i].fetch, regs,
> > - data + tp->args[i].offset);
> > - }
> > -}
> > -
> > -static inline int
> > -print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
> > - u8 *data, void *field)
> > -{
> > - int i;
> > -
> > - for (i = 0; i < nr_args; i++) {
> > - trace_seq_printf(s, " %s=", args[i].name);
> > - if (!args[i].type->print(s, data + args[i].offset, field))
> > - return -ENOMEM;
> > - }
> > - return 0;
> > -}
> > -
> > extern int set_print_fmt(struct trace_probe *tp, bool is_return);
> >
> > #ifdef CONFIG_PERF_EVENTS
> > diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
> > new file mode 100644
> > index 000000000000..c8a5272abf01
> > --- /dev/null
> > +++ b/kernel/trace/trace_probe_tmpl.h
> > @@ -0,0 +1,120 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Traceprobe fetch helper inlines
> > + */
> > +
> > +static nokprobe_inline void
> > +fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
> > +{
> > + switch (code->size) {
> > + case 1:
> > + *(u8 *)buf = (u8)val;
> > + break;
> > + case 2:
> > + *(u16 *)buf = (u16)val;
> > + break;
> > + case 4:
> > + *(u32 *)buf = (u32)val;
> > + break;
> > + case 8:
> > + //TBD: 32bit signed
> > + *(u64 *)buf = (u64)val;
> > + break;
> > + default:
> > + *(unsigned long *)buf = val;
> > + }
> > +}
> > +
> > +static nokprobe_inline void
> > +fetch_apply_bitfield(struct fetch_insn *code, void *buf)
> > +{
> > + switch (code->basesize) {
> > + case 1:
> > + *(u8 *)buf <<= code->lshift;
> > + *(u8 *)buf >>= code->rshift;
> > + break;
> > + case 2:
> > + *(u16 *)buf <<= code->lshift;
> > + *(u16 *)buf >>= code->rshift;
> > + break;
> > + case 4:
> > + *(u32 *)buf <<= code->lshift;
> > + *(u32 *)buf >>= code->rshift;
> > + break;
> > + case 8:
> > + *(u64 *)buf <<= code->lshift;
> > + *(u64 *)buf >>= code->rshift;
> > + break;
> > + }
> > +}
> > +
> > +/* Define this for each callsite */
> > +static int
> > +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,
> > + void *dest, bool pre);
> > +
> > +/* Sum up total data length for dynamic arraies (strings) */
> > +static nokprobe_inline int
> > +__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
> > +{
> > + struct probe_arg *arg;
> > + int i, ret = 0;
> > + u32 len;
> > +
> > + for (i = 0; i < tp->nr_args; i++) {
> > + arg = tp->args + i;
> > + if (unlikely(arg->dynamic)) {
> > + process_fetch_insn(arg->code, regs, &len, true);
> > + ret += len;
> > + }
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +/* Store the value of each argument */
> > +static nokprobe_inline void
> > +store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
> > + u8 *data, int maxlen)
> > +{
> > + struct probe_arg *arg;
> > + u32 end = tp->size;
> > + u32 *dl; /* Data (relative) location */
> > + int i;
> > +
> > + for (i = 0; i < tp->nr_args; i++) {
> > + arg = tp->args + i;
> > + if (unlikely(arg->dynamic)) {
> > + /*
> > + * First, we set the relative location and
> > + * maximum data length to *dl
> > + */
> > + dl = (u32 *)(data + arg->offset);
> > + *dl = make_data_rloc(maxlen, end - arg->offset);
> > + /* Then try to fetch string or dynamic array data */
> > + process_fetch_insn(arg->code, regs, dl, false);
> > + /* Reduce maximum length */
> > + end += get_rloc_len(*dl);
> > + maxlen -= get_rloc_len(*dl);
> > + /* Trick here, convert data_rloc to data_loc */
> > + *dl = convert_rloc_to_loc(*dl, ent_size + arg->offset);
> > + } else
> > + /* Just fetching data normally */
> > + process_fetch_insn(arg->code, regs, data + arg->offset,
> > + false);
> > + }
> > +}
> > +
> > +static inline int
> > +print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
> > + u8 *data, void *field)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < nr_args; i++) {
> > + trace_seq_printf(s, " %s=", args[i].name);
> > + if (!args[i].type->print(s, data + args[i].offset, field))
> > + return -ENOMEM;
> > + }
> > + return 0;
> > +}
> > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> > index 887da2bb63aa..9fc0123c721f 100644
> > --- a/kernel/trace/trace_uprobe.c
> > +++ b/kernel/trace/trace_uprobe.c
> > @@ -27,6 +27,7 @@
> > #include <linux/rculist.h>
> >
> > #include "trace_probe.h"
> > +#include "trace_probe_tmpl.h"
> >
> > #define UPROBE_EVENT_SYSTEM "uprobes"
> >
> > @@ -109,37 +110,19 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
> > /*
> > * Uprobes-specific fetch functions
> > */
> > -#define DEFINE_FETCH_stack(type) \
> > -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
> > - void *offset, void *dest) \
> > -{ \
> > - *(type *)dest = (type)get_user_stack_nth(regs, \
> > - ((unsigned long)offset)); \
> > -}
> > -DEFINE_BASIC_FETCH_FUNCS(stack)
> > -/* No string on the stack entry */
> > -#define fetch_stack_string NULL
> > -#define fetch_stack_string_size NULL
> > -
> > -#define DEFINE_FETCH_memory(type) \
> > -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
> > - void *addr, void *dest) \
> > -{ \
> > - type retval; \
> > - void __user *vaddr = (void __force __user *) addr; \
> > - \
> > - if (copy_from_user(&retval, vaddr, sizeof(type))) \
> > - *(type *)dest = 0; \
> > - else \
> > - *(type *) dest = retval; \
> > +static nokprobe_inline int
> > +probe_user_read(void *dest, void *src, size_t size)
> > +{
> > + void __user *vaddr = (void __force __user *)src;
> > +
> > + return copy_from_user(dest, vaddr, size);
> > }
> > -DEFINE_BASIC_FETCH_FUNCS(memory)
> > /*
> > * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
> > * length and relative data location.
> > */
> > -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
> > - void *addr, void *dest)
> > +static nokprobe_inline void
> > +fetch_store_string(unsigned long addr, void *dest)
> > {
> > long ret;
> > u32 rloc = *(u32 *)dest;
> > @@ -160,8 +143,9 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
> > }
> > }
> >
> > -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
> > - void *addr, void *dest)
> > +/* Return the length of string -- including null terminal byte */
> > +static nokprobe_inline void
> > +fetch_store_strlen(unsigned long addr, void *dest)
> > {
> > int len;
> > void __user *vaddr = (void __force __user *) addr;
> > @@ -174,7 +158,7 @@ static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
> > *(u32 *)dest = len;
> > }
> >
> > -static unsigned long translate_user_vaddr(void *file_offset)
> > +static unsigned long translate_user_vaddr(unsigned long file_offset)
> > {
> > unsigned long base_addr;
> > struct uprobe_dispatch_data *udd;
> > @@ -182,44 +166,79 @@ static unsigned long translate_user_vaddr(void *file_offset)
> > udd = (void *) current->utask->vaddr;
> >
> > base_addr = udd->bp_addr - udd->tu->offset;
> > - return base_addr + (unsigned long)file_offset;
> > + return base_addr + file_offset;
> > }
> >
> > -#define DEFINE_FETCH_file_offset(type) \
> > -static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
> > - void *offset, void *dest)\
> > -{ \
> > - void *vaddr = (void *)translate_user_vaddr(offset); \
> > - \
> > - FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
> > +/* Note that we don't verify it, since the code does not come from user space */
> > +static int
> > +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
> > + bool pre)
> > +{
> > + unsigned long val;
> > + int ret;
> > +
> > + /* 1st stage: get value from context */
> > + switch (code->op) {
> > + case FETCH_OP_REG:
> > + val = regs_get_register(regs, code->param);
> > + break;
> > + case FETCH_OP_STACK:
> > + val = get_user_stack_nth(regs, code->param);
> > + break;
> > + case FETCH_OP_STACKP:
> > + val = user_stack_pointer(regs);
> > + break;
> > + case FETCH_OP_RETVAL:
> > + val = regs_return_value(regs);
> > + break;
> > + case FETCH_OP_IMM:
> > + val = code->immediate;
> > + break;
> > + case FETCH_OP_FOFFS:
> > + val = translate_user_vaddr(code->immediate);
> > + break;
> > + default:
> > + return -EILSEQ;
> > + }
> > + code++;
> > +
> > + /* 2nd stage: dereference memory if needed */
> > + while (code->op == FETCH_OP_DEREF) {
> > + ret = probe_user_read(&val, (void *)val + code->offset,
> > + sizeof(val));
> > + if (ret)
> > + return ret;
> > + code++;
> > + }
> > +
> > + /* 3rd stage: store value to buffer */
> > + switch (code->op) {
> > + case FETCH_OP_ST_RAW:
> > + fetch_store_raw(val, code, dest);
> > + break;
> > + case FETCH_OP_ST_MEM:
> > + probe_user_read(dest, (void *)val + code->offset, code->size);
> > + break;
> > + case FETCH_OP_ST_STRING:
> > + if (pre)
> > + fetch_store_strlen(val + code->offset, dest);
> > + else
> > + fetch_store_string(val + code->offset, dest);
> > + break;
> > + default:
> > + return -EILSEQ;
> > + }
> > + code++;
> > +
> > + /* 4th stage: modify stored value if needed */
> > + if (code->op == FETCH_OP_MOD_BF) {
> > + fetch_apply_bitfield(code, dest);
> > + code++;
> > + }
> > +
> > + return code->op == FETCH_OP_END ? 0 : -EILSEQ;
> > }
> > -DEFINE_BASIC_FETCH_FUNCS(file_offset)
> > -DEFINE_FETCH_file_offset(string)
> > -DEFINE_FETCH_file_offset(string_size)
> > -
> > -/* Fetch type information table */
> > -static const struct fetch_type uprobes_fetch_type_table[] = {
> > - /* Special types */
> > - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
> > - sizeof(u32), 1, "__data_loc char[]"),
> > - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
> > - string_size, sizeof(u32), 0, "u32"),
> > - /* Basic types */
> > - ASSIGN_FETCH_TYPE(u8, u8, 0),
> > - ASSIGN_FETCH_TYPE(u16, u16, 0),
> > - ASSIGN_FETCH_TYPE(u32, u32, 0),
> > - ASSIGN_FETCH_TYPE(u64, u64, 0),
> > - ASSIGN_FETCH_TYPE(s8, u8, 1),
> > - ASSIGN_FETCH_TYPE(s16, u16, 1),
> > - ASSIGN_FETCH_TYPE(s32, u32, 1),
> > - ASSIGN_FETCH_TYPE(s64, u64, 1),
> > - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
> > - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
> > -
> > - ASSIGN_FETCH_TYPE_END
> > -};
> > +NOKPROBE_SYMBOL(process_fetch_insn)
> >
> > static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
> > {
> > @@ -538,8 +557,7 @@ static int create_trace_uprobe(int argc, char **argv)
> >
> > /* Parse fetch argument */
> > ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
> > - is_return, false,
> > - uprobes_fetch_type_table);
> > + is_return, false);
> > if (ret) {
> > pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
> > goto error;
> >


--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>