On Mon, Jun 5, 2023 at 6:42 PM Song Liu <song@xxxxxxxxxx> wrote: > > On Mon, Jun 5, 2023 at 12:40 AM Puranjay Mohan <puranjay12@xxxxxxxxx> wrote: > > > > This will be used by BPF JIT compiler to dump JITed binary to a RX huge > > page, and thus allow multiple BPF programs sharing the a huge (2MB) > > page. > > > > The bpf_prog_pack allocator that implements the above feature allocates > > a RX/RW buffer pair. The JITed code is written to the RW buffer and then > > this function will be used to copy the code from RW to RX buffer. > > > > Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx> > > Acked-by: Song Liu <song@xxxxxxxxxx> > > With a nit below. > > > --- > > arch/arm64/include/asm/patching.h | 1 + > > arch/arm64/kernel/patching.c | 39 +++++++++++++++++++++++++++++++ > > 2 files changed, 40 insertions(+) > > > > diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h > > index 68908b82b168..dba9eb392bf1 100644 > > --- a/arch/arm64/include/asm/patching.h > > +++ b/arch/arm64/include/asm/patching.h > > @@ -8,6 +8,7 @@ int aarch64_insn_read(void *addr, u32 *insnp); > > int aarch64_insn_write(void *addr, u32 insn); > > > > int aarch64_insn_write_literal_u64(void *addr, u64 val); > > +void *aarch64_insn_copy(void *addr, const void *opcode, size_t len); > > > > int aarch64_insn_patch_text_nosync(void *addr, u32 insn); > > int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); > > diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c > > index b4835f6d594b..48c710f6a1ff 100644 > > --- a/arch/arm64/kernel/patching.c > > +++ b/arch/arm64/kernel/patching.c > > @@ -105,6 +105,45 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val) > > return ret; > > } > > > > +/** > > + * aarch64_insn_copy - Copy instructions into (an unused part of) RX memory > > + * @addr: address to modify > > + * @opcode: source of the copy > > + * @len: length to copy > > + * > > + * Useful for JITs to dump new code blocks into unused regions of RX memory. > > + */ > > nit: > I understand "addr" and "opcode" are used by x86 text_poke_copy(). But maybe > we should call them "dst" and "src" or "to" and "from" or something similar? Sure, I will call it "dst" and "src" in the next version. Thanks, Puranjay
