Messages in this thread Patch in this message | | | From | Björn Töpel <> | Subject | Re: [PATCH 4/7] riscv: Simplify text patching loops | Date | Mon, 19 Feb 2024 14:03:18 +0100 |
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Samuel Holland <samuel.holland@sifive.com> writes:
> This reduces the number of variables and makes the code easier to parse. > > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> > --- > > arch/riscv/kernel/patch.c | 21 +++++++++++---------- > 1 file changed, 11 insertions(+), 10 deletions(-) > > diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c > index bccd9ed04a05..7f030b46eae5 100644 > --- a/arch/riscv/kernel/patch.c > +++ b/arch/riscv/kernel/patch.c > @@ -155,7 +155,6 @@ NOKPROBE_SYMBOL(__patch_insn_write); > > static int patch_insn_set(void *addr, u8 c, size_t len) > { > - size_t patched = 0; > size_t size; > int ret = 0; > > @@ -163,11 +162,12 @@ static int patch_insn_set(void *addr, u8 c, size_t len) > * __patch_insn_set() can only work on 2 pages at a time so call it in a > * loop with len <= 2 * PAGE_SIZE. > */ > - while (patched < len && !ret) { > - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); > - ret = __patch_insn_set(addr + patched, c, size); > + while (len && !ret) { > + size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr), len); > + ret = __patch_insn_set(addr, c, size);
While you're at it, do: ret = __patch_insn_set(addr, c, size); if (ret) return ret; ... return 0; }
and simplify the while-loop predicate?
> > - patched += size; > + addr += size; > + len -= size; > } > > return ret; > @@ -190,7 +190,6 @@ NOKPROBE_SYMBOL(patch_text_set_nosync); > > int patch_insn_write(void *addr, const void *insn, size_t len) > { > - size_t patched = 0; > size_t size; > int ret = 0; > > @@ -198,11 +197,13 @@ int patch_insn_write(void *addr, const void *insn, size_t len) > * Copy the instructions to the destination address, two pages at a time > * because __patch_insn_write() can only handle len <= 2 * PAGE_SIZE. > */ > - while (patched < len && !ret) { > - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched); > - ret = __patch_insn_write(addr + patched, insn + patched, size); > + while (len && !ret) { > + size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr), len); > + ret = __patch_insn_write(addr, insn, size);
Same comment as above.
Björn
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