On Sun, Mar 06, 2022 at 07:59:24PM +0100, soe...@soeren-tempel.net wrote: > From: Sören Tempel <soeren+...@soeren-tempel.net> > > The .regs member is primarily intended to be used in conjunction with > ptrace. Since this code is not using ptrace, using .regs is a bad idea. > Furthermore, the code currently fails to compile on musl since the > pt_regs type (used by .regs) is in an incomplete type which has to be > completed by inclusion of the asm/ptrace.h Kernel header. Contrary to > glibc, this header is not indirectly included by musl through other > header files. > > This patch fixes compilation of this code with musl libc by accessing > the register values via .gp_regs/.gregs (depending on 32-bit or 64-bit > PowerPC) instead of using .regs. For more details, see > https://gcc.gnu.org/pipermail/gcc-patches/2022-March/591261.html > > For the offsets in gp_regs refer to the Kernel asm/ptrace.h header. > > This patch has been tested on Alpine Linux ppc64le (uses musl libc). > > Signed-off-by: Sören Tempel <soe...@soeren-tempel.net> > > ChangeLog: > > * libgo/runtime/go-signal.c (defined): Use .gp_regs/.gregs > to access ppc64/ppc32 registers. > (dumpregs): Ditto. > --- > Changes since v1: Use .gp_regs/.gregs instead of .regs based on > feedback by Rich Felker, thereby avoiding the need to include > asm/ptrace.h for struct pt_regs. > > libgo/runtime/go-signal.c | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/libgo/runtime/go-signal.c b/libgo/runtime/go-signal.c > index d30d1603adc..647ad606019 100644 > --- a/libgo/runtime/go-signal.c > +++ b/libgo/runtime/go-signal.c > @@ -224,7 +224,11 @@ getSiginfo(siginfo_t *info, void *context > __attribute__((unused))) > #elif defined(__alpha__) && defined(__linux__) > ret.sigpc = ((ucontext_t*)(context))->uc_mcontext.sc_pc; > #elif defined(__PPC__) && defined(__linux__) > - ret.sigpc = ((ucontext_t*)(context))->uc_mcontext.regs->nip; > +#ifdef __PPC64__ > + ret.sigpc = ((ucontext_t*)(context))->uc_mcontext.gp_regs[32]; > +#else > + ret.sigpc = ((ucontext_t*)(context))->uc_mcontext.gregs[32]; > +#endif > #elif defined(__PPC__) && defined(_AIX) > ret.sigpc = ((ucontext_t*)(context))->uc_mcontext.jmp_context.iar; > #elif defined(__aarch64__) && defined(__linux__) > @@ -338,16 +342,21 @@ dumpregs(siginfo_t *info __attribute__((unused)), void > *context __attribute__((u > #elif defined(__PPC__) && defined(__LITTLE_ENDIAN__) && defined(__linux__) > { > mcontext_t *m = &((ucontext_t*)(context))->uc_mcontext; > +#ifdef __PPC64__ > + greg_t *gp = &m->gp_regs; > +#else > + greg_t *gp = &m->gregs; > +#endif
Have you tried compiling this? It looks like it's a constraint violation because gregset_t has array type and & will produce a pointer to the array type rather than a pointer to the first element. You should drop the & to get the pointer to the first element. Rich
