PSTACK_ITER(3PROC) Process Control Library Functions PSTACK_ITER(3PROC)
NAME
Pstack_iter - iterate process stack frames
LIBRARY
Process Control Library (libproc, -lproc)
SYNOPSIS
#include <libproc.h> int Pstack_iter(
struct ps_prochandle *P,
const prgregset_t regs,
proc_stack_f *func,
void *data);
DESCRIPTION
The
Pstack_iter() function iterates over the stack frames in the process
P starting at the point defined by
regs.
For each valid stack frame encountered, the callback function
func is
invoked with
data passed as argument. The full signature of
proc_stack_f is defined in
libproc(3LIB). With each callback, a register set, argument
set, and argument count will be provided. In that register set, only a
subset of the registers will be valid, which include the frame pointer,
program counter, and on SPARC systems, the next program counter. These
registers can be accessed with the constants
R_FP,
R_PC, and
R_nPC respectively. These correspond to the registers
%ebp and
%eip on i386,
%rbp and
%rip on amd64,
%fp,
%pc, and
%npc on both SPARC and SPARCv9.
Callers will receive a callback for the first stack frame indicated by
regs and then will receive a subsequent callback for each caller of that frame
until no such frame can be found. Stack frames that logically come after
the frame indicated by
regs will not receive callbacks.
The compiler can either facilitate or stymie the iteration of the stack.
Programs that have been compiled in such a way as to omit the frame pointer
will result in truncated stacks. Similarly, if the initial set of
registers passed in via
regs is invalid, then the ability to iterate the
stack will be limited. The return value of
func controls whether or not
iteration continues. If
func returns
0 then iteration continues. However,
if
func returns non-zero, then iteration will halt and that value will be
used as the return value of the
Pstack_iter() function. Because
Pstack_iter() returns
-1 on internal failure it is recommended the callback
function not return
-1 to indicate an error. Thus the caller may
distinguish between the failure of the callback function and the failure of
the
Pstack_iter() function.
RETURN VALUES
Upon successful completion, the
Pstack_iter() function returns
0. If there
was an internal error then
-1 is returned. Otherwise, if the callback
function
func returns non-zero, then its return value will be returned
instead.
INTERFACE STABILITY
UncommittedMT-LEVEL See
LOCKING in
libproc(3LIB).
SEE ALSO
libproc(3LIB),
proc(5)illumos May 11, 2016 illumos