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Diffstat (limited to 'Documentation/trace/fprobetrace.rst')
| -rw-r--r-- | Documentation/trace/fprobetrace.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/trace/fprobetrace.rst b/Documentation/trace/fprobetrace.rst index b4c2ca3d02c1..3439bc9bd351 100644 --- a/Documentation/trace/fprobetrace.rst +++ b/Documentation/trace/fprobetrace.rst @@ -50,13 +50,23 @@ Synopsis of fprobe-events $argN : Fetch the Nth function argument. (N >= 1) (\*2) $retval : Fetch return value.(\*3) $comm : Fetch current task comm. + $current : Fetch the address of the current task_struct. +|-[u]OFFS(FETCHARG) : Fetch memory at FETCHARG +|- OFFS address.(\*4)(\*5) + this_cpu_read(FETCHARG) : Read the value of the per-CPU variable FETCHARG on the current CPU. + this_cpu_ptr(FETCHARG) : Get the address of the per-CPU variable FETCHARG on the current CPU. \IMM : Store an immediate value to the argument. NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types (x8/x16/x32/x64), "char", "string", "ustring", "symbol", "symstr" and bitfield are supported. + (STRUCT[,ASGN])FIELD->MEMBER[->MEMBER] : If BTF is supported, typecast FIELD to + a pointer to STRUCT and then derference the pointer defined by + ->MEMBER. ASGN can be specified optionally. If ASGN is specified, + FIELD will be cast to the same offset position as the ASGN member, + rather than to the beginning of the STRUCT. + (STRUCT[,ASGN])(FETCHARG)->MEMBER[->MEMBER] : typecast can nest, so the above can + also be used with another FETCHARG instead of FIELD. (\*1) This is available only when BTF is enabled. (\*2) only for the probe on function entry (offs == 0). Note, this argument access |