From: Mark Rutland <mark.rutland@arm.com>
To: He Zhe <zhe.he@windriver.com>
Cc: catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de,
bp@alien8.de, dave.hansen@linux.intel.com, keescook@chromium.org,
alexander.shishkin@linux.intel.com, jolsa@kernel.org,
namhyung@kernel.org, benh@kernel.crashing.org, paulus@samba.org,
borntraeger@linux.ibm.com, svens@linux.ibm.com, hpa@zytor.com,
x86@kernel.org, linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC 1/8] stacktrace: Change callback prototype to pass more information
Date: Tue, 19 Apr 2022 14:09:14 +0100 [thread overview]
Message-ID: <Yl60euwfis+u92cA@FVFF77S0Q05N> (raw)
In-Reply-To: <20220418132217.1573072-2-zhe.he@windriver.com>
On Mon, Apr 18, 2022 at 09:22:10PM +0800, He Zhe wrote:
> Currently stack_trace_consume_fn can only have pc of each frame of the
> stack. Copying-beyond-the-frame-detection also needs fp of current and
> previous frame. Other detection algorithm in the future may need more
> information of the frame.
>
> We define a frame_info to include them all.
>
>
> Signed-off-by: He Zhe <zhe.he@windriver.com>
> ---
> include/linux/stacktrace.h | 9 ++++++++-
> kernel/stacktrace.c | 10 +++++-----
> 2 files changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
> index 97455880ac41..5a61bfafe6f0 100644
> --- a/include/linux/stacktrace.h
> +++ b/include/linux/stacktrace.h
> @@ -10,15 +10,22 @@ struct pt_regs;
>
> #ifdef CONFIG_ARCH_STACKWALK
>
> +struct frame_info {
> + unsigned long pc;
> + unsigned long fp;
> + unsigned long prev_fp;
> +};
I don't think this should be exposed through a generic interface; the `fp` and
`prev_fp` values are only meaningful with arch-specific knowledge, and they're
*very* easy to misuse (e.g. when transitioning from one stack to another).
There's also a bunch of other information one may or may not want, depending on
what you're trying to achieve.
I am happy to have an arch-specific internal unwinder where we can access this
information, and *maybe* it makes sense to have a generic API that passes some
opaque token, but I don't think we should make the structure generic.
Thanks,
Mark.
> +
> /**
> * stack_trace_consume_fn - Callback for arch_stack_walk()
> * @cookie: Caller supplied pointer handed back by arch_stack_walk()
> * @addr: The stack entry address to consume
> + * @fi: The frame information to consume
> *
> * Return: True, if the entry was consumed or skipped
> * False, if there is no space left to store
> */
> -typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr);
> +typedef bool (*stack_trace_consume_fn)(void *cookie, struct frame_info *fi);
> /**
> * arch_stack_walk - Architecture specific function to walk the stack
> * @consume_entry: Callback which is invoked by the architecture code for
> diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
> index 9ed5ce989415..2d0a2812e92b 100644
> --- a/kernel/stacktrace.c
> +++ b/kernel/stacktrace.c
> @@ -79,7 +79,7 @@ struct stacktrace_cookie {
> unsigned int len;
> };
>
> -static bool stack_trace_consume_entry(void *cookie, unsigned long addr)
> +static bool stack_trace_consume_entry(void *cookie, struct frame_info *fi)
> {
> struct stacktrace_cookie *c = cookie;
>
> @@ -90,15 +90,15 @@ static bool stack_trace_consume_entry(void *cookie, unsigned long addr)
> c->skip--;
> return true;
> }
> - c->store[c->len++] = addr;
> + c->store[c->len++] = fi->pc;
> return c->len < c->size;
> }
>
> -static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr)
> +static bool stack_trace_consume_entry_nosched(void *cookie, struct frame_info *fi)
> {
> - if (in_sched_functions(addr))
> + if (in_sched_functions(fi->pc))
> return true;
> - return stack_trace_consume_entry(cookie, addr);
> + return stack_trace_consume_entry(cookie, fi);
> }
>
> /**
> --
> 2.25.1
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-04-19 13:57 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-18 13:22 [PATCH RFC 0/8] hardened usercopy and stacktrace improvement He Zhe
2022-04-18 13:22 ` [PATCH RFC 1/8] stacktrace: Change callback prototype to pass more information He Zhe
2022-04-19 13:09 ` Mark Rutland [this message]
2022-04-19 14:13 ` He Zhe
2022-04-18 13:22 ` [PATCH RFC 2/8] arm64: stacktrace: Add arch_within_stack_frames He Zhe
2022-04-18 21:59 ` Kees Cook
2022-04-19 14:01 ` He Zhe
2022-04-20 7:32 ` David Laight
2022-04-19 14:40 ` Mark Rutland
2022-04-21 9:20 ` He Zhe
2022-04-18 13:22 ` [PATCH RFC 3/8] arm64: stacktrace: Make callbacks use new prototype with frame info He Zhe
2022-04-18 13:22 ` [PATCH RFC 4/8] powerpc: " He Zhe
2022-04-18 13:22 ` [PATCH RFC 5/8] riscv: " He Zhe
2022-04-18 13:22 ` [PATCH RFC 6/8] s390: " He Zhe
2022-04-18 13:22 ` [PATCH RFC 7/8] x86: " He Zhe
2022-04-18 13:22 ` [PATCH RFC 8/8] lkdtm: usercopy: Make USERCOPY_STACK_FRAME_x able to work for all archs He Zhe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Yl60euwfis+u92cA@FVFF77S0Q05N \
--to=mark.rutland@arm.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=benh@kernel.crashing.org \
--cc=borntraeger@linux.ibm.com \
--cc=bp@alien8.de \
--cc=catalin.marinas@arm.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jolsa@kernel.org \
--cc=keescook@chromium.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=linux-s390@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=namhyung@kernel.org \
--cc=paulus@samba.org \
--cc=svens@linux.ibm.com \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
--cc=x86@kernel.org \
--cc=zhe.he@windriver.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).