On 4/6/2026 8:49 PM, Dylan Hatch wrote: > The .sframe in kernel modules is built without SFRAME_F_FDE_SORTED set. > In order to allow sframe PC lookup in modules, add a code path to handle > unsorted FDE tables by doing a simple linear search. > > Signed-off-by: Dylan Hatch <[email protected]>
With my below two minor comments considered: Reviewed-by: Jens Remus <[email protected]> > diff --git a/include/linux/sframe.h b/include/linux/sframe.h > @@ -64,6 +64,7 @@ struct sframe_section { > unsigned long text_start; > unsigned long text_end; > > + bool fdes_sorted; > unsigned long fdes_start; > unsigned long fres_start; > unsigned long fres_end; The struct would be smaller if the bool fdes_sorted flag would be inserted after the unsigned int num_fdes field: $ pahole -C sframe_section kernel/unwind/sframe.o Yours: size: 96 With bool fdes_sorted moved after unsigned int num_fdes: size: 88 > diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c > @@ -179,9 +179,34 @@ static __always_inline int __read_fde(struct > sframe_section *sec, > return -EFAULT; > } > > -static __always_inline int __find_fde(struct sframe_section *sec, > - unsigned long ip, > - struct sframe_fde_internal *fde) > +static __always_inline int __find_fde_unsorted(struct sframe_section *sec, > + unsigned long ip, > + struct sframe_fde_internal *fde) > +{ > + struct sframe_fde_v3 *cur, *start, *end; > + > + start = (struct sframe_fde_v3 *)sec->fdes_start; > + end = start + sec->num_fdes; > + > + for (cur = start; cur < end; cur++) { > + s64 func_off; > + u32 func_size; > + unsigned long func_addr; > + > + DATA_GET(sec, func_off, &cur->func_start_off, s64, Efault); > + DATA_GET(sec, func_size, &cur->func_size, u32, Efault); > + func_addr = (unsigned long)cur + func_off; > + > + if (ip >= func_addr && ip < func_addr + func_size) > + return __read_fde(sec, cur - start, fde); > + } __find_fde() (now __find_fde_sorted()) returns -EINVAL, if no FDE is found: return -EINVAL; > +Efault: > + return -EFAULT; > +} Regards, Jens -- Jens Remus Linux on Z Development (D3303) [email protected] / [email protected] IBM Deutschland Research & Development GmbH; Vorsitzender des Aufsichtsrats: Wolfgang Wendt; Geschäftsführung: David Faller; Sitz der Gesellschaft: Ehningen; Registergericht: Amtsgericht Stuttgart, HRB 243294 IBM Data Privacy Statement: https://www.ibm.com/privacy/
