Re: [PATCH v2 3/5] gdbstub: Save target's siginfo

[Gustavo Romero]

Hi Alex,

On 3/7/24 7:33 PM, Alex Bennée wrote:
> Richard Henderson <richard.henderson@linaro.org> writes:
>
> > On 3/7/24 08:26, Gustavo Romero wrote:
> > > Save target's siginfo into gdbserver_state so it can be used later, for
> > > example, in any stub that requires the target's si_signo and si_code.
> > > This change affects only linux-user mode.
> > > Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
> > > Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> > > ---
> > >    gdbstub/internals.h    |  3 +++
> > >    gdbstub/user-target.c  |  3 ++-
> > >    gdbstub/user.c         | 14 ++++++++++----
> > >    include/gdbstub/user.h |  6 +++++-
> > >    linux-user/main.c      |  2 +-
> > >    linux-user/signal.c    |  5 ++++-
> > >    6 files changed, 25 insertions(+), 8 deletions(-)
> > > diff --git a/gdbstub/internals.h b/gdbstub/internals.h
> > > index 56b7c13b75..a7cc69dab3 100644
> > > --- a/gdbstub/internals.h
> > > +++ b/gdbstub/internals.h
> > > @@ -58,6 +58,9 @@ typedef struct GDBState {
> > >        int line_csum; /* checksum at the end of the packet */
> > >        GByteArray *last_packet;
> > >        int signal;
> > > +#ifdef CONFIG_USER_ONLY
> > > +    uint8_t siginfo[MAX_SIGINFO_LENGTH];
> > > +#endif
> >
> > If we this in GDBUserState in user.c -- no need for ifdefs then.
>
> Although it does break on FreeBSD's user target:
>
>    FAILED: libqemu-arm-bsd-user.fa.p/gdbstub_user-target.c.o
>    cc -m64 -mcx16 -Ilibqemu-arm-bsd-user.fa.p -I. -I.. -Itarget/arm -I../target/arm 
> -I../common-user/host/x86_64 -I../bsd-user/include -Ibsd-user/freebsd -I../bsd-user/freebsd 
> -I../bsd-user/host/x86_64 -Ibsd-user -I../bsd-user -I../bsd-user/arm -Iqapi -Itrace -Iui 
> -Iui/shader -I/usr/local/include/capstone -I/usr/local/include/glib-2.0 
> -I/usr/local/lib/glib-2.0/include -I/usr/local/include -fdiagnostics-color=auto -Wall -Winvalid-pch 
> -Werror -std=gnu11 -O2 -g -fstack-protector-strong -Wempty-body -Wendif-labels 
> -Wexpansion-to-defined -Wformat-security -Wformat-y2k -Wignored-qualifiers -Winit-self 
> -Wmissing-format-attribute -Wmissing-prototypes -Wnested-externs -Wold-style-definition 
> -Wredundant-decls -Wstrict-prototypes -Wtype-limits -Wundef -Wvla -Wwrite-strings 
> -Wno-gnu-variable-sized-type-not-at-end -Wno-initializer-overrides -Wno-missing-include-dirs 
> -Wno-psabi -Wno-shift-negative-value -Wno-string-plus-int -Wno-tautological-type-limit-compare 
> -Wno-typedef-redefinition -Wthread-safety -iquote . -iquote /tmp/cirrus-ci-build -iquote 
> /tmp/cirrus-ci-build/include -iquote /tmp/cirrus-ci-build/host/include/x86_64 -iquote 
> /tmp/cirrus-ci-build/host/include/generic -iquote /tmp/cirrus-ci-build/tcg/i386 -pthread 
> -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv 
> -ftrivial-auto-var-init=zero -fPIE -DNEED_CPU_H 
> '-DCONFIG_TARGET="arm-bsd-user-config-target.h"' 
> '-DCONFIG_DEVICES="arm-bsd-user-config-devices.h"' -MD -MQ 
> libqemu-arm-bsd-user.fa.p/gdbstub_user-target.c.o -MF 
> libqemu-arm-bsd-user.fa.p/gdbstub_user-target.c.o.d -o 
> libqemu-arm-bsd-user.fa.p/gdbstub_user-target.c.o -c ../gdbstub/user-target.c
>    In file included from ../gdbstub/user-target.c:18:
>    ../gdbstub/internals.h:62:21: error: use of undeclared identifier 
> 'MAX_SIGINFO_LENGTH'
>       62 |     uint8_t siginfo[MAX_SIGINFO_LENGTH];
>          |                     ^
>    1 error generated.
>    [2084/6731] Compiling C object libqemu-arm
>
> See: https://gitlab.com/stsquad/qemu/-/jobs/6345829419

argh, I've tested all targets for linux-user, but missed bsd-user. I've tried
once to build it but that requires a BSD-like host, which I don't have at the
moment, then I forgot about it... Let me setup one and review the change in
the light of the comments from you and Richard.

Thanks!


Cheers,
Gustavo