On 27.06.2018 16:31, Janosch Frank wrote:
> Right now we only catch the exceptions that we really expect to
> receive. Let's at least catch all of them and abort if any of the
> unexpected ones fell on our foot.
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> ---
>
> I hope I understood you correctly, as assembly is not my strongest
> language skill.
>
> ---
> lib/s390x/interrupt.c | 24 +++++++++++++++++++++
> s390x/cstart64.S | 58 ++++++++++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 79 insertions(+), 3 deletions(-)
>
> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
> index bc44e3a..848d5f2 100644
> --- a/lib/s390x/interrupt.c
> +++ b/lib/s390x/interrupt.c
> @@ -104,3 +104,27 @@ void handle_pgm_int(void)
> pgm_int_expected = false;
> fixup_pgm_int();
> }
> +
> +void handle_ext_int(void)
> +{
> + report_abort("Unexpected external call interrupt: at %#lx",
> + lc->ext_old_psw.addr);
> +}
> +
> +void handle_mcck_int(void)
> +{
> + report_abort("Unexpected machine check interrupt: at %#lx",
> + lc->mcck_old_psw.addr);
> +}
> +
> +void handle_io_int(void)
> +{
> + report_abort("Unexpected io interrupt: at %#lx",
> + lc->io_old_psw.addr);
> +}
> +
> +void handle_svc_int(void)
> +{
> + report_abort("Unexpected service call interrupt: at %#lx",
> + lc->svc_old_psw.addr);
> +}
We need prototypes for these in lib/s390x/asm/interrupt.h if I'm not wrong.
> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
> index 9a26ed3..3ead2d2 100644
> --- a/s390x/cstart64.S
> +++ b/s390x/cstart64.S
> @@ -26,6 +26,18 @@ init_psw_cont:
> /* setup pgm interrupt handler */
> larl %r1, pgm_int_psw
> mvc GEN_LC_PGM_NEW_PSW(16), 0(%r1)
> + /* setup ext interrupt handler */
> + larl %r1, ext_int_psw
> + mvc GEN_LC_EXT_NEW_PSW(16), 0(%r1)
> + /* setup mcck interrupt handler */
> + larl %r1, mcck_int_psw
> + mvc GEN_LC_MCCK_NEW_PSW(16), 0(%r1)
> + /* setup io interrupt handler */
> + larl %r1, ext_int_psw
> + mvc GEN_LC_IO_NEW_PSW(16), 0(%r1)
> + /* setup svc interrupt handler */
> + larl %r1, mcck_int_psw
> + mvc GEN_LC_SVC_NEW_PSW(16), 0(%r1)
> /* setup cr0, enabling e.g. AFP-register control */
> larl %r1, initital_cr0
> lctlg %c0, %c0, 0(%r1)
> @@ -42,7 +54,7 @@ init_psw_cont:
> /* call exit() */
> j exit
>
> -pgm_int:
> +.macro SAVE_REGS
I remember that macros are also intended (looking at e.g.
arch/s390/kernel/entry.S)
> /* save grs 0-15 */
> stmg %r0, %r15, GEN_LC_SW_INT_GRS
> /* save fprs 0-15 + fpc */
> @@ -64,8 +76,9 @@ pgm_int:
> std %f14, 112(%r1)
> std %f15, 120(%r1)
> stfpc GEN_LC_SW_INT_FPC
> - /* call our c handler */
> - brasl %r14, handle_pgm_int
> +.endm
> +
> +.macro RESTORE_REGS
> /* restore fprs 0-15 + fpc */
> larl %r1, GEN_LC_SW_INT_FPRS
> ld %f0, 0(%r1)
> @@ -87,13 +100,52 @@ pgm_int:
> lfpc GEN_LC_SW_INT_FPC
> /* restore grs 0-15 */
> lmg %r0, %r15, GEN_LC_SW_INT_GRS
> +.endm
> +
> +.section .text
> +pgm_int:
> + SAVE_REGS
> + brasl %r14, handle_pgm_int
> + RESTORE_REGS
> lpswe GEN_LC_PGM_OLD_PSW
>
> +ext_int:
> + SAVE_REGS
> + brasl %r14, handle_ext_int
> + RESTORE_REGS
> + lpswe GEN_LC_EXT_OLD_PSW
> +
> +mcck_int:
> + SAVE_REGS
> + brasl %r14, handle_mcck_int
> + RESTORE_REGS
> + lpswe GEN_LC_MCCK_OLD_PSW
> +
> +io_int:
> + SAVE_REGS
> + brasl %r14, handle_io_int
> + RESTORE_REGS
> + lpswe GEN_LC_IO_OLD_PSW
> +
> +svc_int:
> + SAVE_REGS
> + brasl %r14, handle_svc_int
> + RESTORE_REGS
> + lpswe GEN_LC_SVC_OLD_PSW
> +
> .align 8
> initital_psw:
> .quad 0x0000000180000000, init_psw_cont
> pgm_int_psw:
> .quad 0x0000000180000000, pgm_int
> +ext_int_psw:
> + .quad 0x0000000180000000, ext_int
> +mcck_int_psw:
> + .quad 0x0000000180000000, mcck_int
> +io_int_psw:
> + .quad 0x0000000180000000, io_int
> +svc_int_psw:
> + .quad 0x0000000180000000, svc_int
> initital_cr0:
> /* enable AFP-register control, so FP regs (+BFP instr) can be used */
> .quad 0x0000000000040000
>
Apart from that, looks good to me.
--
Thanks,
David / dhildenb
