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

From: Namhyung Kim
Date: Thu Feb 22 2018 - 23:30:16 EST

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)
* unify fetch type table

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;
>