I've come across this patch in downstream review (although I really have zero background in s390x), and Cornelia suggested I might want to repeat my comments on the upstream list too:
On 05/04/18 09:25, Cornelia Huck wrote: > From: Collin Walling <wall...@linux.ibm.com> > > Rename the loadparm char array in main.c to loadparm_str and > increased the size by one byte to account for a null termination > when converting the loadparm string to an int via atoui. We > also allow the boot menu to be enabled when loadparm is set to > an empty string or a series of spaces. > > Signed-off-by: Collin Walling <wall...@linux.ibm.com> > Reported-by: Vasily Gorbik <g...@linux.ibm.com> > Reviewed-by: Thomas Huth <th...@redhat.com> > Reviewed-by: Janosch Frank <fran...@linux.ibm.com> > Signed-off-by: Thomas Huth <th...@redhat.com> > --- > hw/s390x/ipl.c | 4 ++++ > pc-bios/s390-ccw/main.c | 14 +++++++------- > 2 files changed, 11 insertions(+), 7 deletions(-) > > diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c > index fb554ab156..150f6c0582 100644 > --- a/hw/s390x/ipl.c > +++ b/hw/s390x/ipl.c > @@ -373,6 +373,10 @@ int s390_ipl_set_loadparm(uint8_t *loadparm) > loadparm[i] = ascii2ebcdic[(uint8_t) lp[i]]; > } > > + if (i < 8) { > + memset(loadparm + i, 0x40, 8 - i); /* fill with EBCDIC spaces */ > + } > + > g_free(lp); > return 0; > } > diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c > index 9d9f8cf4d3..26f9adf84a 100644 > --- a/pc-bios/s390-ccw/main.c > +++ b/pc-bios/s390-ccw/main.c > @@ -15,11 +15,11 @@ > char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); > static SubChannelId blk_schid = { .one = 1 }; > IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE))); > -static char loadparm[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; > +static char loadparm_str[9] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 }; > QemuIplParameters qipl; > > #define LOADPARM_PROMPT "PROMPT " > -#define LOADPARM_EMPTY "........" > +#define LOADPARM_EMPTY " " > #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL) > > /* > @@ -45,7 +45,7 @@ void panic(const char *string) > > unsigned int get_loadparm_index(void) > { > - return atoui(loadparm); > + return atoui(loadparm_str); > } > > static bool find_dev(Schib *schib, int dev_no) > @@ -80,13 +80,13 @@ static bool find_dev(Schib *schib, int dev_no) > > static void menu_setup(void) > { > - if (memcmp(loadparm, LOADPARM_PROMPT, 8) == 0) { > + if (memcmp(loadparm_str, LOADPARM_PROMPT, 8) == 0) { > menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0); > return; > } > > /* If loadparm was set to any other value, then do not enable menu */ > - if (memcmp(loadparm, LOADPARM_EMPTY, 8) != 0) { > + if (memcmp(loadparm_str, LOADPARM_EMPTY, 8) != 0) { > return; > } > > @@ -116,8 +116,8 @@ static void virtio_setup(void) > */ > enable_mss_facility(); > > - sclp_get_loadparm_ascii(loadparm); > - memcpy(ldp + 10, loadparm, 8); > + sclp_get_loadparm_ascii(loadparm_str); > + memcpy(ldp + 10, loadparm_str, 8); > sclp_print(ldp); > > memcpy(&qipl, early_qipl, sizeof(QemuIplParameters)); > So here I said, "There are a bunch of naked 8 constants; those should all be (sizeof loadparm_str - 1), I think. Should be a separate patch, of course." Thanks Laszlo