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Message-ID: <ZzkSB7QETdOd1S2X@krava>
Date: Sat, 16 Nov 2024 22:43:35 +0100
From: Jiri Olsa <olsajiri@...il.com>
To: Andrii Nakryiko <andrii.nakryiko@...il.com>
Cc: Oleg Nesterov <oleg@...hat.com>, Peter Zijlstra <peterz@...radead.org>,
Andrii Nakryiko <andrii@...nel.org>, bpf@...r.kernel.org,
Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
John Fastabend <john.fastabend@...il.com>,
Hao Luo <haoluo@...gle.com>, Steven Rostedt <rostedt@...dmis.org>,
Masami Hiramatsu <mhiramat@...nel.org>,
Alan Maguire <alan.maguire@...cle.com>,
linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org
Subject: Re: [RFC perf/core 04/11] uprobes: Add data argument to
uprobe_write_opcode function
On Thu, Nov 14, 2024 at 03:41:08PM -0800, Andrii Nakryiko wrote:
> On Tue, Nov 5, 2024 at 5:34 AM Jiri Olsa <jolsa@...nel.org> wrote:
> >
> > Adding data argument to uprobe_write_opcode function and passing
> > it to newly added arch overloaded functions:
> >
> > arch_uprobe_verify_opcode
> > arch_uprobe_is_register
> >
> > This way each architecture can provide custmized verification.
> >
> > Signed-off-by: Jiri Olsa <jolsa@...nel.org>
> > ---
> > include/linux/uprobes.h | 6 +++++-
> > kernel/events/uprobes.c | 25 +++++++++++++++++++------
> > 2 files changed, 24 insertions(+), 7 deletions(-)
> >
> > diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
> > index 7d23a4fee6f4..be306028ed59 100644
> > --- a/include/linux/uprobes.h
> > +++ b/include/linux/uprobes.h
> > @@ -182,7 +182,7 @@ extern bool is_trap_insn(uprobe_opcode_t *insn);
> > extern unsigned long uprobe_get_swbp_addr(struct pt_regs *regs);
> > extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs);
> > extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
> > - unsigned long vaddr, uprobe_opcode_t *insn, int len);
> > + unsigned long vaddr, uprobe_opcode_t *insn, int len, void *data);
> > extern struct uprobe *uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc);
> > extern int uprobe_apply(struct uprobe *uprobe, struct uprobe_consumer *uc, bool);
> > extern void uprobe_unregister_nosync(struct uprobe *uprobe, struct uprobe_consumer *uc);
> > @@ -215,6 +215,10 @@ extern void uprobe_handle_trampoline(struct pt_regs *regs);
> > extern void *arch_uretprobe_trampoline(unsigned long *psize);
> > extern unsigned long uprobe_get_trampoline_vaddr(void);
> > extern void uprobe_copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len);
> > +extern int uprobe_verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode);
> > +extern int arch_uprobe_verify_opcode(struct page *page, unsigned long vaddr,
> > + uprobe_opcode_t *new_opcode, void *data);
> > +extern bool arch_uprobe_is_register(uprobe_opcode_t *insn, int len, void *data);
> > #else /* !CONFIG_UPROBES */
> > struct uprobes_state {
> > };
> > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> > index 3e275717789b..944d9df1f081 100644
> > --- a/kernel/events/uprobes.c
> > +++ b/kernel/events/uprobes.c
> > @@ -264,7 +264,13 @@ static void copy_to_page(struct page *page, unsigned long vaddr, const void *src
> > kunmap_atomic(kaddr);
> > }
> >
> > -static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)
> > +__weak bool arch_uprobe_is_register(uprobe_opcode_t *insn, int len, void *data)
> > +{
> > + return is_swbp_insn(insn);
> > +}
> > +
> > +int uprobe_verify_opcode(struct page *page, unsigned long vaddr,
> > + uprobe_opcode_t *new_opcode)
> > {
> > uprobe_opcode_t old_opcode;
> > bool is_swbp;
> > @@ -292,6 +298,12 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
> > return 1;
> > }
> >
> > +__weak int arch_uprobe_verify_opcode(struct page *page, unsigned long vaddr,
> > + uprobe_opcode_t *new_opcode, void *data)
>
> why wrapping lines? even original longer code was single line
hm, adding 'uprobe_opcode_t *new_opcode' would make the line over 100 chars,
but right, surrouding code is not strict ;-) ok
jirka
>
>
> > +{
> > + return uprobe_verify_opcode(page, vaddr, new_opcode);
> > +}
> > +
> > static struct delayed_uprobe *
> > delayed_uprobe_check(struct uprobe *uprobe, struct mm_struct *mm)
> > {
> > @@ -471,7 +483,8 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm,
> > * Return 0 (success) or a negative errno.
> > */
> > int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
> > - unsigned long vaddr, uprobe_opcode_t *insn, int len)
> > + unsigned long vaddr, uprobe_opcode_t *insn, int len,
> > + void *data)
> > {
> > struct uprobe *uprobe;
> > struct page *old_page, *new_page;
> > @@ -480,7 +493,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
> > bool orig_page_huge = false;
> > unsigned int gup_flags = FOLL_FORCE;
> >
> > - is_register = is_swbp_insn(insn);
> > + is_register = arch_uprobe_is_register(insn, len, data);
> > uprobe = container_of(auprobe, struct uprobe, arch);
> >
> > retry:
> > @@ -491,7 +504,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
> > if (IS_ERR(old_page))
> > return PTR_ERR(old_page);
> >
> > - ret = verify_opcode(old_page, vaddr, insn);
> > + ret = arch_uprobe_verify_opcode(old_page, vaddr, insn, data);
> > if (ret <= 0)
> > goto put_old;
> >
> > @@ -584,7 +597,7 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned
> > {
> > uprobe_opcode_t insn = UPROBE_SWBP_INSN;
> >
> > - return uprobe_write_opcode(auprobe, mm, vaddr, &insn, UPROBE_SWBP_INSN_SIZE);
> > + return uprobe_write_opcode(auprobe, mm, vaddr, &insn, UPROBE_SWBP_INSN_SIZE, NULL);
> > }
> >
> > /**
> > @@ -600,7 +613,7 @@ int __weak
> > set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
> > {
> > return uprobe_write_opcode(auprobe, mm, vaddr,
> > - (uprobe_opcode_t *)&auprobe->insn, UPROBE_SWBP_INSN_SIZE);
> > + (uprobe_opcode_t *)&auprobe->insn, UPROBE_SWBP_INSN_SIZE, NULL);
> > }
> >
> > /* uprobe should have guaranteed positive refcount */
> > --
> > 2.47.0
> >
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