Re: [PATCH v8 04/15] hw/i386/pc: replace use of strtol with qemu_strtol in x86_load_linux()

[Philippe Mathieu-Daudé]

On 10/11/19 9:26 AM, Sergio Lopez wrote:
> Philippe Mathieu-Daudé <address@hidden> writes:
>
> > Hi Sergio,
> >
> > On 10/10/19 4:31 PM, Sergio Lopez wrote:
> > > Follow checkpatch.pl recommendation and replace the use of strtol with
> > > qemu_strtol in x86_load_linux().
> > >
> > > Signed-off-by: Sergio Lopez <address@hidden>
> > > ---
> > >    hw/i386/pc.c | 11 +++++++++--
> > >    1 file changed, 9 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > > index 77e86bfc3d..e6bcc3ff42 100644
> > > --- a/hw/i386/pc.c
> > > +++ b/hw/i386/pc.c
> > > @@ -68,6 +68,7 @@
> > >    #include "qemu/config-file.h"
> > >    #include "qemu/error-report.h"
> > >    #include "qemu/option.h"
> > > +#include "qemu/cutils.h"
> > >    #include "hw/acpi/acpi.h"
> > >    #include "hw/acpi/cpu_hotplug.h"
> > >    #include "hw/boards.h"
> > > @@ -1201,7 +1202,8 @@ static void x86_load_linux(PCMachineState *pcms,
> > >        /* handle vga= parameter */
> > >        vmode = strstr(kernel_cmdline, "vga=");
> > >        if (vmode) {
> > > -        unsigned int video_mode;
> > > +        long video_mode;
> >
> > Why do you change 'video_mode' to a signed type?
>
> qemu_strtol fourth argument is a pointer to long int. According to
> "linux/Documentation/admin-guide/svga.rst", valid video modes are in the
> in the range of 0x0 to 0xffff (matching the stw_p below), so this change
> shouldn't be a problem.

Why not simply use qemu_strtoui() then? Later stw_p() implicitly cast 
this to uint16_t anyway.

Any thought from other reviewers? Do we care? I'm feeling being a pain 
with Sergio :/

> > > +        int ret;
> > >            /* skip "vga=" */
> > >            vmode += 4;
> > >            if (!strncmp(vmode, "normal", 6)) {
> > > @@ -1211,7 +1213,12 @@ static void x86_load_linux(PCMachineState *pcms,
> > >            } else if (!strncmp(vmode, "ask", 3)) {
> > >                video_mode = 0xfffd;
> > >            } else {
> > > -            video_mode = strtol(vmode, NULL, 0);
> > > +            ret = qemu_strtol(vmode, NULL, 0, &video_mode);
> > > +            if (ret != 0) {
> > > +                fprintf(stderr, "qemu: can't parse 'vga' parameter: %s\n",
> > > +                        strerror(-ret));
> > > +                exit(1);
> > > +            }
> > >            }
> > >            stw_p(header + 0x1fa, video_mode);
> > >        }