Commit ee44f4e7 authored Jan 09, 2026 by Heiko Carstens

s390/traps: Copy monitor code to pt_regs



In case of a monitor call program check the CPU stores the monitor code to
lowcore. Let the program check handler copy it to the pt_regs structure so
it can be used by the monitor call exception handler.

Instead of increasing the pt_regs size add a union which contains both
orig_gpr2 and monitor_code, since orig_gpr2 is not used in case of a
program check.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

parent 8cbfd136

arch/s390/include/asm/ptrace.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -120,7 +120,10 @@ struct pt_regs {
		unsigned long gprs[NUM_GPRS];
		};
		};
		union {
		unsigned long orig_gpr2;
		unsigned long monitor_code;
		};
		union {
		struct {
		unsigned int int_code;

arch/s390/kernel/traps.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -298,6 +298,7 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
		teid.val = lc->trans_exc_code;
		regs->int_code = lc->pgm_int_code;
		regs->int_parm_long = teid.val;
		regs->monitor_code = lc->monitor_code;
		/*
		* In case of a guest fault, short-circuit the fault handler and return.
		* This way the sie64a() function will return 0; fault address and