| Message ID | 20210616011209.1446045-9-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | linux-user: Move signal trampolines to new page | expand |
+Helge On 6/16/21 3:11 AM, Richard Henderson wrote: > We cannot use a raw sigtramp page for hppa, > but must wait for full vdso support. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/hppa/target_signal.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h > index 7f525362e9..d558119ee7 100644 > --- a/linux-user/hppa/target_signal.h > +++ b/linux-user/hppa/target_signal.h > @@ -71,4 +71,18 @@ typedef struct target_sigaltstack { > /* mask for all SS_xxx flags */ > #define TARGET_SS_FLAG_BITS TARGET_SS_AUTODISARM > > +/* > + * We cannot use a bare sigtramp page for hppa-linux. > + * > + * Unlike other guests where we use the instructions at PC to validate > + * an offset from SP, the hppa libgcc signal frame fallback unwinding uses > + * the PC address itself to find the frame. This is due to the fact that > + * the hppa grows the stack upward, and the frame is of unknown size. > + * > + * TODO: We should be able to use a VDSO to address this, by providing > + * proper unwind info for the sigtramp code, at which point the fallback > + * unwinder will not be used. > + */ > +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 > + > #endif /* HPPA_TARGET_SIGNAL_H */ > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Richard Henderson <richard.henderson@linaro.org> writes: > We cannot use a raw sigtramp page for hppa, > but must wait for full vdso support. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > --- > linux-user/hppa/target_signal.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h > index 7f525362e9..d558119ee7 100644 > --- a/linux-user/hppa/target_signal.h > +++ b/linux-user/hppa/target_signal.h > @@ -71,4 +71,18 @@ typedef struct target_sigaltstack { > /* mask for all SS_xxx flags */ > #define TARGET_SS_FLAG_BITS TARGET_SS_AUTODISARM > > +/* > + * We cannot use a bare sigtramp page for hppa-linux. > + * > + * Unlike other guests where we use the instructions at PC to validate > + * an offset from SP, the hppa libgcc signal frame fallback unwinding uses > + * the PC address itself to find the frame. This is due to the fact that > + * the hppa grows the stack upward, and the frame is of unknown size. > + * > + * TODO: We should be able to use a VDSO to address this, by providing > + * proper unwind info for the sigtramp code, at which point the fallback > + * unwinder will not be used. > + */ > +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 > + > #endif /* HPPA_TARGET_SIGNAL_H */ -- Alex Bennée
diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h index 7f525362e9..d558119ee7 100644 --- a/linux-user/hppa/target_signal.h +++ b/linux-user/hppa/target_signal.h @@ -71,4 +71,18 @@ typedef struct target_sigaltstack { /* mask for all SS_xxx flags */ #define TARGET_SS_FLAG_BITS TARGET_SS_AUTODISARM +/* + * We cannot use a bare sigtramp page for hppa-linux. + * + * Unlike other guests where we use the instructions at PC to validate + * an offset from SP, the hppa libgcc signal frame fallback unwinding uses + * the PC address itself to find the frame. This is due to the fact that + * the hppa grows the stack upward, and the frame is of unknown size. + * + * TODO: We should be able to use a VDSO to address this, by providing + * proper unwind info for the sigtramp code, at which point the fallback + * unwinder will not be used. + */ +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 + #endif /* HPPA_TARGET_SIGNAL_H */
We cannot use a raw sigtramp page for hppa, but must wait for full vdso support. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/hppa/target_signal.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) -- 2.25.1