NAME
uwx_get_reg() — read a register from current frame's context
SYNOPSIS
#include <uwx.h>
int uwx_get_reg(
struct uwx_env *env,
int regid,
uint64_t *valp
);
DESCRIPTION
uwx_get_reg()
is part of the Unwind Express Library for Integrity systems; see
uwx(3X).
uwx_get_reg()
reads the value of a register from the context of the current frame.
Parameters
- env
A pointer to an unwind environment object.
- regid
An identifier for the register to be read.
This parameter must be one of the following values:
- UWX_REG_IP
The instruction pointer (IP).
- UWX_REG_SP
The stack pointer (SP).
- UWX_REG_BSP
The backing store pointer (BSP).
This value defines the point in the backing store where
the current frame's GR32 would be saved.
- UWX_REG_CFM
The current frame marker (CFM) and epilogue counter (ar.ec),
combined into one register as they are stored in ar.pfs.
- UWX_REG_RP
The return pointer (RP, the previous frame's IP).
- UWX_REG_PSP
The previous stack pointer (PSP, the previous frame's SP).
- UWX_REG_PFS
The previous frame state (PFS, the previous frame's CFM and ar.ec).
Note that this is not necessarily the same as
UWX_REG_AR_PFS,
as the previous frame's state may have been saved to a different register
prior to making a function call.
Asking for this register will locate the true previous frame state,
whether it is currently in ar.pfs or saved in a different register.
- UWX_REG_PREDS
Predicate registers PR0-PR63.
Only the preserved predicates have meaningful values.
- UWX_REG_PRIUNAT
The NaT bits for GR4-7 in the current frame.
- UWX_REG_AR_RNAT
The RSE NaT collection register (ar.rnat).
- UWX_REG_AR_UNAT
The User NaT collection register (ar.unat).
- UWX_REG_AR_FPSR
The floating-point status register (ar.fpsr).
- UWX_REG_AR_LC
The loop counter register (ar.lc).
- UWX_REG_AR_PFS
The previous function state register (ar.pfs).
Note that this is not necessarily the same as UWX_REG_PFS,
as the previous frame's state may have been saved to a different register
prior to making a function call.
Asking for this register will return the contents of the ar.pfs
register for the current frame.
- UWX_REG_GR(x)
General register
GRx.
Only registers GR4-GR7 (the preserved GRs)
and GR32-GR127 (the stacked GRs) may be read.
- UWX_REG_BR(x)
Branch register
BRx.
Only registers BR1-BR5 (the preserved BRs) may be read.
- UWX_REG_FR(x)
Floating-point register
GRx.
Only registers FR2-FR5 and FR16-31 (the preserved FRs)
may be read.
- valp
Pointer to the return buffer where the value is written.
The buffer must be 16 bytes long for floating-point values,
or 8 bytes long for all other values.
RETURN VALUE
uwx_get_reg()
returns
UWX_OK
on success.
See
uwx(3X)
for error codes.
AUTHOR
The Unwind Express Library was developed by Hewlett-Packard.
SEE ALSO
uwx(3X),
uwx_add_to_bsp(3X),
uwx_find_source_info(3X),
uwx_find_symbol(3X),
uwx_free(3X),
uwx_get_abi_context_code(3X),
uwx_get_funcstart(3X),
uwx_get_module_info(3X),
uwx_get_nat(3X),
uwx_get_source_info(3X),
uwx_get_sym_info(3X),
uwx_init(3X),
uwx_init_context(3X),
uwx_register_alloc_cb(3X),
uwx_register_callbacks(3X),
uwx_release_symbol_cache(3X),
uwx_self_do_context_frame(3X),
uwx_self_free_info(3X),
uwx_self_init_context(3X),
uwx_self_init_info(3X),
uwx_set_nofr(3X),
uwx_set_remote(3X),
uwx_step(3X),
uwx_step_inline(3X).
Printable version
