From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Xin Li <xin3.li@intel.com>, Dave Hansen <dave.hansen@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Cooper <Andrew.Cooper3@citrix.com>,
Peter Zijlstra <peterz@infradead.org>,
Brian Gerst <brgerst@gmail.com>, Borislav Petkov <bp@alien8.de>,
Shuah Khan <shuah@kernel.org>, Ingo Molnar <mingo@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
x86 Mailing List <x86@kernel.org>,
Linux Kselftest Mailing List <linux-kselftest@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v1 1/2] selftests/x86: sysret_rip: Handle syscall in a FRED system
Date: Fri, 27 Jan 2023 03:16:25 +0700 [thread overview]
Message-ID: <Y9LfmQ/r1/pEP+uv@biznet-home.integral.gnuweeb.org> (raw)
In-Reply-To: <8f5c24df-514d-5d89-f58f-ec8c3eb1e049@zytor.com>
[ Resending, missed Xin Li from the Cc list... ]
On Mon, Jan 23, 2023 at 05:40:23PM -0800, H. Peter Anvin wrote:
> So as per Andrew's comment, add:
>
> register void * rsp asm("%rsp");
>
> ...
>
> "+r" (rsp) /* clobber the redzone */
>
> ... as the right way to avoid redzone problems.
I played with this more. I found something wrong with this. This doesn't
work for me. The compiler still uses red zone despite I use "+r" (rsp).
What did I do wrong?
-----
ammarfaizi2@integral2:/tmp$ gcc -fno-stack-protector -O2 -Wall -Wextra test.c -o test
ammarfaizi2@integral2:/tmp$ objdump --no-show-raw-insn -d test | grep "a_leaf_func_with_red_zone>:" -A8
0000000000001180 <a_leaf_func_with_red_zone>:
1180: endbr64
1184: mov $0x1,%eax
1189: mov %rax,-0x8(%rsp) ## BUG!!!
118e: pushf
118f: pop %rax
1190: mov -0x8(%rsp),%rax ## BUG!!!
1195: ret
ammarfaizi2@integral2:/tmp$ clang -O2 -Wall -Wextra test.c -o test
ammarfaizi2@integral2:/tmp$ objdump --no-show-raw-insn -d test | grep "a_leaf_func_with_red_zone>:" -A6
0000000000001140 <a_leaf_func_with_red_zone>:
1140: mov $0x1,%eax
1145: mov %rax,-0x8(%rsp) ## BUG!!!
114a: pushf
114b: pop %rax
114c: mov -0x8(%rsp),%rax ## BUG!!!
1151: ret
-----
ammarfaizi2@integral2:~$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
ammarfaizi2@integral2:~$ clang --version
Ubuntu clang version 16.0.0 (++20230124031324+d63e492562f2-1~exp1~20230124151444.705)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
-----
test.c:
#include <stdio.h>
static inline void clobber_redzone(void)
{
register void *rsp __asm__("%rsp");
unsigned long rflags;
__asm__ volatile ("pushf; popq %1"
: "+r" (rsp), "=r" (rflags));
}
static inline void set_red_zone(long *mem, long val)
{
__asm__ volatile ("movq %[val], %[mem]"
: [mem] "=m" (*mem)
: [val] "r" (val));
}
static inline long get_red_zone(long *mem)
{
long ret;
__asm__ volatile ("movq %[in], %[out]"
: [out] "=r" (ret)
: [in] "m" (*mem));
return ret;
}
__attribute__((__noinline__))
long a_leaf_func_with_red_zone(void)
{
long x;
set_red_zone(&x, 1);
clobber_redzone();
/* The correct retval is 1 */
return get_red_zone(&x);
}
int main(void)
{
printf("ret = %ld\n", a_leaf_func_with_red_zone());
return 0;
}
--
Ammar Faizi
next prev parent reply other threads:[~2023-01-26 20:16 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <SA1PR11MB6734FA9139B9C9F6CC2ED123A8C59@SA1PR11MB6734.namprd11.prod.outlook.com>
2023-01-20 17:45 ` the x86 sysret_rip test fails on the Intel FRED architecture Dave Hansen
[not found] ` <eb81f7f2-d266-d999-b41a-e6eae086e731@citrix.com>
2023-01-20 20:50 ` H. Peter Anvin
2023-01-20 21:10 ` Andrew Cooper
2023-01-20 21:17 ` H. Peter Anvin
2023-01-20 21:29 ` Andrew Cooper
2023-01-21 4:59 ` H. Peter Anvin
2023-01-21 16:46 ` Dave Hansen
2023-01-21 21:47 ` Brian Gerst
2023-01-22 3:01 ` Li, Xin3
2023-01-22 3:28 ` H. Peter Anvin
2023-01-22 3:38 ` Li, Xin3
2023-01-22 4:34 ` Dave Hansen
2023-01-22 4:44 ` H. Peter Anvin
2023-01-22 8:22 ` Li, Xin3
2023-01-22 8:54 ` Ammar Faizi
2023-01-22 9:40 ` H. Peter Anvin
2023-01-22 23:45 ` H. Peter Anvin
2023-01-23 9:02 ` Ammar Faizi
2023-01-23 19:43 ` H. Peter Anvin
2023-01-23 23:43 ` Ammar Faizi
2023-01-23 23:58 ` H. Peter Anvin
2023-01-24 0:26 ` [RFC PATCH v1 0/2] selftests/x86: sysret_rip update for FRED system Ammar Faizi
2023-01-24 0:26 ` [RFC PATCH v1 1/2] selftests/x86: sysret_rip: Handle syscall in a " Ammar Faizi
2023-01-24 1:40 ` H. Peter Anvin
2023-01-24 2:31 ` Ammar Faizi
2023-01-26 20:08 ` Ammar Faizi
2023-02-15 9:17 ` Andrew Cooper
2023-02-15 10:29 ` Andrew Cooper
2023-02-15 10:44 ` Ammar Faizi
2023-02-15 10:42 ` Ammar Faizi
2023-01-26 20:16 ` Ammar Faizi [this message]
2023-01-24 0:26 ` [RFC PATCH v1 2/2] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-23 23:53 ` the x86 sysret_rip test fails on the Intel FRED architecture Andrew Cooper
2023-01-24 0:01 ` H. Peter Anvin
2023-01-24 2:27 ` [RFC PATCH v2 0/2] selftests/x86: sysret_rip update for FRED system Ammar Faizi
2023-01-24 2:27 ` [RFC PATCH v2 1/2] selftests/x86: sysret_rip: Handle syscall in a " Ammar Faizi
2023-01-24 5:44 ` H. Peter Anvin
2023-01-24 2:27 ` [RFC PATCH v2 2/2] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-24 6:16 ` H. Peter Anvin
2023-01-24 6:41 ` Ammar Faizi
2023-01-24 6:47 ` Ammar Faizi
2023-01-24 9:07 ` H. Peter Anvin
2023-01-24 9:12 ` Ammar Faizi
2023-01-24 10:09 ` [RFC PATCH v3 0/2] selftests/x86: sysret_rip update for FRED system Ammar Faizi
2023-01-24 10:09 ` [RFC PATCH v3 1/2] selftests/x86: sysret_rip: Handle syscall in a " Ammar Faizi
2023-01-24 10:09 ` [RFC PATCH v3 2/2] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-24 20:59 ` H. Peter Anvin
2023-01-25 3:29 ` Ammar Faizi
2023-01-24 21:32 ` [RFC PATCH v3 0/2] selftests/x86: sysret_rip update for FRED system Li, Xin3
2023-01-24 21:37 ` H. Peter Anvin
2023-01-24 23:20 ` Li, Xin3
2023-01-25 3:27 ` Ammar Faizi
2023-01-24 21:51 ` Andrew Cooper
2023-01-24 23:58 ` Li, Xin3
2023-01-25 3:22 ` [RFC PATCH v4 0/2] sysret_rip update for the Intel FRED architecture Ammar Faizi
2023-01-25 3:22 ` [RFC PATCH v4 1/2] selftests/x86: sysret_rip: Handle syscall in a FRED system Ammar Faizi
2023-01-25 3:37 ` Ammar Faizi
2023-01-25 3:44 ` Ammar Faizi
2023-01-25 3:22 ` [RFC PATCH v4 2/2] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-25 3:49 ` [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture Ammar Faizi
2023-01-25 3:49 ` [RFC PATCH v5 1/2] selftests/x86: sysret_rip: Handle syscall in a FRED system Ammar Faizi
2023-01-25 8:39 ` H. Peter Anvin
2023-01-25 8:53 ` Ammar Faizi
2023-01-25 9:57 ` Ammar Faizi
2023-01-25 10:01 ` Ammar Faizi
2023-01-25 10:17 ` H. Peter Anvin
2023-01-25 11:37 ` Ammar Faizi
2023-01-25 17:25 ` H. Peter Anvin
2023-01-25 3:49 ` [RFC PATCH v5 2/2] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-25 8:22 ` [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture Li, Xin3
2023-01-25 8:32 ` Ammar Faizi
2023-01-25 17:07 ` Li, Xin3
2023-01-25 17:24 ` H. Peter Anvin
2023-01-25 17:41 ` Ammar Faizi
2023-01-25 17:48 ` Li, Xin3
2023-02-15 7:42 ` Li, Xin3
2023-02-15 7:51 ` Ammar Faizi
2023-02-18 4:27 ` Ammar Faizi
2023-02-18 4:51 ` H. Peter Anvin
2023-01-25 21:17 ` [RFC PATCH v6 0/3] " Ammar Faizi
2023-01-25 21:17 ` [RFC PATCH v6 1/3] selftests/x86: sysret_rip: Handle syscall in a FRED system Ammar Faizi
2023-01-25 23:01 ` Ammar Faizi
2023-01-25 21:17 ` [RFC PATCH v6 2/3] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-25 21:17 ` [RFC PATCH v6 3/3] selftests/x86: sysret_rip: Test opportunistic SYSRET Ammar Faizi
2023-01-25 23:24 ` [RFC PATCH v7 0/3] sysret_rip update for the Intel FRED architecture Ammar Faizi
2023-01-25 23:24 ` [RFC PATCH v7 1/3] selftests/x86: sysret_rip: Handle syscall in a FRED system Ammar Faizi
2023-01-25 23:24 ` [RFC PATCH v7 2/3] selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` Ammar Faizi
2023-01-25 23:24 ` [RFC PATCH v7 3/3] selftests/x86: sysret_rip: Test SYSRET with a signal handler Ammar Faizi
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=Y9LfmQ/r1/pEP+uv@biznet-home.integral.gnuweeb.org \
--to=ammarfaizi2@gnuweeb.org \
--cc=Andrew.Cooper3@citrix.com \
--cc=bp@alien8.de \
--cc=brgerst@gmail.com \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=xin3.li@intel.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).