Hi Linus,
On Wed, Jun 19, 2024 at 01:25:02PM -0700, Linus Torvalds wrote:
> I've pushed out four branches based on 6.10-rc4, because I think it's
> pretty ready. But I'll rebase them if people have commentary that
> needs addressing, so don't treat them as some kind of stable base yet.
> My plan is to merge them during the next merge window unless somebody
> screams.
>
> The branches are:
>
> arm64-uaccess:
> arm64: access_ok() optimization
> arm64: start using 'asm goto' for put_user()
> arm64: start using 'asm goto' for get_user() when available
> runtime-constants:
> arm64: add 'runtime constant' support
> runtime constants: add x86 architecture support
> runtime constants: add default dummy infrastructure
> vfs: dcache: move hashlen_hash() from callers into d_hash()
Apologies, the arm64 branches/patches have been on my TODO list for
review/test/benchmark for the last couple of weeks, but I haven't had
both the time and machine availability to do so.
Looking at the arm64 runtime constants patch, I see there's a redundant
store in __runtime_fixup_16(), which I think is just a leftover from
applying the last roudn or feedback:
+/* 16-bit immediate for wide move (movz and movk) in bits 5..20 */
+static inline void __runtime_fixup_16(__le32 *p, unsigned int val)
+{
+ u32 insn = le32_to_cpu(*p);
+ insn &= 0xffe0001f;
+ insn |= (val & 0xffff) << 5;
+ *p = insn;
+ *p = cpu_to_le32(insn);
+}
... i.e. the first assignment to '*p' should go; the compiler should be
smart enough to elide it entirely, but it shouldn't be there.
For the sake of review, would you be happy to post the uaccess and
runtime-constants patches to the list again? I think there might be some
remaining issues with (real) PAN and we might need to do a bit more
preparatory work there.
Mark.
