| PSTACK_ITER(3PROC) | Process Control Library Functions | PSTACK_ITER(3PROC) |
Pstack_iter —
iterate process stack frames
Process Control Library (libproc, -lproc)
#include
<libproc.h>
int
Pstack_iter(struct ps_prochandle
*P, const prgregset_t regs,
proc_stack_f *func, void
*data);
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.
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.
See LOCKING in libproc(3LIB).
| May 11, 2016 | OmniOS |