systemtap/rhbz1972805.patch

53 lines
2.2 KiB
Diff

commit 5409ddea1a007384b9c71a78e8dd2cbca1fc5424
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Thu Jul 1 14:41:06 2021 -0400
rhbz1972805: add basic syscall-in-ptregs support for s390x
Akin to commit 7be7af0fda36 for ARM, add basic syscalls via
tracepoints / CONTEXT->sregs support for s390x. The argno=6 case is
funny because for syscalls they travel in registers, whereas normally
they hop onto the stack.
diff --git a/tapset/s390/registers.stp b/tapset/s390/registers.stp
index b3986cdd9..cbe7e8483 100644
--- a/tapset/s390/registers.stp
+++ b/tapset/s390/registers.stp
@@ -136,7 +136,10 @@ function uarch_bytes:long() {
function _stp_get_register_by_offset:long (offset:long) %{ /* pure */
long value;
struct pt_regs *regs;
- regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
+ if (CONTEXT->sregs)
+ regs = CONTEXT->sregs;
+ else
+ regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
if (!regs) {
CONTEXT->last_error = "No registers available in this context";
return;
@@ -169,9 +172,10 @@ function _stp_sign_extend32:long (value:long) {
}
function _stp_register:long (name:string, sign_extend:long) {
- assert(registers_valid(), "cannot access CPU registers in this context")
+ # don't assert this: will get *regs state checked in _stp_get_register_by_offset, and better
+ # assert(registers_valid(), "cannot access CPU registers in this context")
offset = _reg_offsets[name]
- assert(offset != 0 || (name in _reg_offsets), "Unknown register: " . name)
+ assert(offset != 0 || (name in _reg_offsets), "Unknown register: " . name)
value = _stp_get_register_by_offset(offset)
if (probing_32bit_app()) {
if (sign_extend)
@@ -235,8 +239,10 @@ function _stp_arg2:long (argnum:long, sign_extend:long, truncate:long,
val = u_register("r5")
else if (argnum == 5)
val = u_register("r6")
+ else if (argnum == 6 && %{ CONTEXT->sregs != NULL %} ) // linux syscall arg6 goes into r7
+ val = u_register("r7")
else if (argnum >= 6)
- val = _stp_get_kernel_stack_param(argnum - 6)
+ val = _stp_get_kernel_stack_param(argnum - 6);
if ((truncate || @__compat_task) && !force64) {
/* High bits may be garbage. */