| Message ID | 20240702234155.2106399-2-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | target/arm: Fix unwind from dc zva and FEAT_MOPS | expand |
On Wed, 3 Jul 2024 at 00:43, Richard Henderson <richard.henderson@linaro.org> wrote: > > Add wrappers that set and clear helper_retaddr around the > host memory operation. This cannot fail for system mode, > but might raise SIGSEGV for user mode. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > include/exec/cpu_ldst.h | 40 ++++++++++++++++++++++++++++++++++++++++ > accel/tcg/user-exec.c | 22 ++++++++++++++++++++++ > 2 files changed, 62 insertions(+) > > diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h > index 71009f84f5..baf4f9367d 100644 > --- a/include/exec/cpu_ldst.h > +++ b/include/exec/cpu_ldst.h > @@ -379,4 +379,44 @@ void *tlb_vaddr_to_host(CPUArchState *env, abi_ptr addr, > MMUAccessType access_type, int mmu_idx); > #endif > > +/** > + * memset_ra: > + * @p: host pointer > + * @c: data > + * @n: length > + * @ra: unwind return address > + * > + * Like system memset(p,c,n), except manages @ra for the calling > + * helper in the event of a signal. To be used with the result > + * of tlb_vaddr_to_host to resolve the host pointer. > + */ > +#ifdef CONFIG_USER_ONLY > +void *memset_ra(void *p, int c, size_t n, uintptr_t ra); > +#else > +static inline void *memset_ra(void *p, int c, size_t n, uintptr_t ra) > +{ > + return memset(p, c, n); > +} > +#endif > + > +/** > + * memmove_ra: > + * @d: host destination pointer > + * @s: host source pointer > + * @n: length > + * @ra: unwind return address > + * > + * Like system memmove(d,s,n), except manages @ra for the calling > + * helper in the event of a signal. To be used with the result of > + * tlb_vaddr_to_host to resolve the host pointer. > + */ > +#ifdef CONFIG_USER_ONLY > +void *memmove_ra(void *d, const void *s, size_t n, uintptr_t ra); > +#else > +static inline void *memmove_ra(void *d, const void *s, size_t n, uintptr_t ra) > +{ > + return memmove(d, s, n); > +} > +#endif I guess these make sense. I feel like they're a function where the caller needs to be quite careful about what they're doing (e.g. not to use them in a way that the memmove or memset would cross a page boundary if other guest register state needs to be kept in sync with the reported fault address), but I can't think of a useful non-architecture-specific warning that would be worth putting in the doc comments. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> thanks -- PMM
diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h index 71009f84f5..baf4f9367d 100644 --- a/include/exec/cpu_ldst.h +++ b/include/exec/cpu_ldst.h @@ -379,4 +379,44 @@ void *tlb_vaddr_to_host(CPUArchState *env, abi_ptr addr, MMUAccessType access_type, int mmu_idx); #endif +/** + * memset_ra: + * @p: host pointer + * @c: data + * @n: length + * @ra: unwind return address + * + * Like system memset(p,c,n), except manages @ra for the calling + * helper in the event of a signal. To be used with the result + * of tlb_vaddr_to_host to resolve the host pointer. + */ +#ifdef CONFIG_USER_ONLY +void *memset_ra(void *p, int c, size_t n, uintptr_t ra); +#else +static inline void *memset_ra(void *p, int c, size_t n, uintptr_t ra) +{ + return memset(p, c, n); +} +#endif + +/** + * memmove_ra: + * @d: host destination pointer + * @s: host source pointer + * @n: length + * @ra: unwind return address + * + * Like system memmove(d,s,n), except manages @ra for the calling + * helper in the event of a signal. To be used with the result of + * tlb_vaddr_to_host to resolve the host pointer. + */ +#ifdef CONFIG_USER_ONLY +void *memmove_ra(void *d, const void *s, size_t n, uintptr_t ra); +#else +static inline void *memmove_ra(void *d, const void *s, size_t n, uintptr_t ra) +{ + return memmove(d, s, n); +} +#endif + #endif /* CPU_LDST_H */ diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index 80d24540ed..a73da42e3a 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -1289,3 +1289,25 @@ static void *atomic_mmu_lookup(CPUState *cpu, vaddr addr, MemOpIdx oi, #define DATA_SIZE 16 #include "atomic_template.h" #endif + +void *memset_ra(void *p, int c, size_t n, uintptr_t ra) +{ + void *r; + + set_helper_retaddr(ra); + r = memset(p, c, n); + clear_helper_retaddr(); + + return r; +} + +void *memmove_ra(void *d, const void *s, size_t n, uintptr_t ra) +{ + void *r; + + set_helper_retaddr(ra); + r = memmove(d, s, n); + clear_helper_retaddr(); + + return r; +}
Add wrappers that set and clear helper_retaddr around the host memory operation. This cannot fail for system mode, but might raise SIGSEGV for user mode. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- include/exec/cpu_ldst.h | 40 ++++++++++++++++++++++++++++++++++++++++ accel/tcg/user-exec.c | 22 ++++++++++++++++++++++ 2 files changed, 62 insertions(+)