| Message ID | mpt36fz730h.fsf@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix unchecked use of tree_to_uhwi in tree-ssa-strlen.c | expand |
On 10/11/19 8:47 AM, Richard Sandiford wrote: > r273783 introduced an unchecked use of tree_to_uhwi. This is > tested by the SVE ACLE patches, but could potentially trigger > in non-SVE cases too. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install? I wasn't able to come up with a C test case that triggers the bug but the fix seems obviously safe and correct to me. Thanks for handling it! Martin > > Richard > > > 2019-10-11 Richard Sandiford <richard.sandiford@arm.com> > > gcc/ > * tree-ssa-strlen.c (count_nonzero_bytes): Check tree_fits_uhwi_p > before using tree_to_uhwi. > > Index: gcc/tree-ssa-strlen.c > =================================================================== > --- gcc/tree-ssa-strlen.c 2019-10-11 15:43:51.127514545 +0100 > +++ gcc/tree-ssa-strlen.c 2019-10-11 15:46:11.718524445 +0100 > @@ -4026,10 +4026,10 @@ count_nonzero_bytes (tree exp, unsigned > > /* The size of the MEM_REF access determines the number of bytes. */ > tree type = TREE_TYPE (exp); > - if (tree typesize = TYPE_SIZE_UNIT (type)) > - nbytes = tree_to_uhwi (typesize); > - else > + tree typesize = TYPE_SIZE_UNIT (type); > + if (!typesize || !tree_fits_uhwi_p (typesize)) > return false; > + nbytes = tree_to_uhwi (typesize); > > /* Handle MEM_REF = SSA_NAME types of assignments. */ > return count_nonzero_bytes (arg, offset, nbytes, lenrange, nulterm, >
On Fri, Oct 11, 2019 at 4:47 PM Richard Sandiford <richard.sandiford@arm.com> wrote: > > r273783 introduced an unchecked use of tree_to_uhwi. This is > tested by the SVE ACLE patches, but could potentially trigger > in non-SVE cases too. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install? OK. Richard. > Richard > > > 2019-10-11 Richard Sandiford <richard.sandiford@arm.com> > > gcc/ > * tree-ssa-strlen.c (count_nonzero_bytes): Check tree_fits_uhwi_p > before using tree_to_uhwi. > > Index: gcc/tree-ssa-strlen.c > =================================================================== > --- gcc/tree-ssa-strlen.c 2019-10-11 15:43:51.127514545 +0100 > +++ gcc/tree-ssa-strlen.c 2019-10-11 15:46:11.718524445 +0100 > @@ -4026,10 +4026,10 @@ count_nonzero_bytes (tree exp, unsigned > > /* The size of the MEM_REF access determines the number of bytes. */ > tree type = TREE_TYPE (exp); > - if (tree typesize = TYPE_SIZE_UNIT (type)) > - nbytes = tree_to_uhwi (typesize); > - else > + tree typesize = TYPE_SIZE_UNIT (type); > + if (!typesize || !tree_fits_uhwi_p (typesize)) > return false; > + nbytes = tree_to_uhwi (typesize); > > /* Handle MEM_REF = SSA_NAME types of assignments. */ > return count_nonzero_bytes (arg, offset, nbytes, lenrange, nulterm,
Index: gcc/tree-ssa-strlen.c =================================================================== --- gcc/tree-ssa-strlen.c 2019-10-11 15:43:51.127514545 +0100 +++ gcc/tree-ssa-strlen.c 2019-10-11 15:46:11.718524445 +0100 @@ -4026,10 +4026,10 @@ count_nonzero_bytes (tree exp, unsigned /* The size of the MEM_REF access determines the number of bytes. */ tree type = TREE_TYPE (exp); - if (tree typesize = TYPE_SIZE_UNIT (type)) - nbytes = tree_to_uhwi (typesize); - else + tree typesize = TYPE_SIZE_UNIT (type); + if (!typesize || !tree_fits_uhwi_p (typesize)) return false; + nbytes = tree_to_uhwi (typesize); /* Handle MEM_REF = SSA_NAME types of assignments. */ return count_nonzero_bytes (arg, offset, nbytes, lenrange, nulterm,