From: Jiashuo Liang <liangjs@pku.edu.cn>
To: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org, Jiashuo Liang <liangjs@pku.edu.cn>
Subject: [PATCH] x86/fault: Fix wrong signal when vsyscall fails with pkey
Date: Wed, 28 Jul 2021 19:44:13 +0800 [thread overview]
Message-ID: <20210728114413.287611-1-liangjs@pku.edu.cn> (raw)
The function __bad_area_nosemaphore calls kernelmode_fixup_or_oops with
parameter "signal" being "pkey", which will send a signal numbered "pkey".
When emulating vsyscall, the kernel may fail to access user-given memory
pages that are protected by pkey. In such a case, the kernel should send a
SIGSEGV signal with si_code=SEGV_PKUERR and si_pkey=pkey.
So a new parameter "pkey" is added to kernelmode_fixup_or_oops to fix it.
Signed-off-by: Jiashuo Liang <liangjs@pku.edu.cn>
---
arch/x86/mm/fault.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index b2eefdefc108..883294282e1e 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -710,7 +710,8 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code,
static noinline void
kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, int signal, int si_code)
+ unsigned long address, int signal, int si_code,
+ u32 pkey)
{
WARN_ON_ONCE(user_mode(regs));
@@ -735,8 +736,12 @@ kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,
set_signal_archinfo(address, error_code);
- /* XXX: hwpoison faults will set the wrong code. */
- force_sig_fault(signal, si_code, (void __user *)address);
+ if (si_code == SEGV_PKUERR) {
+ force_sig_pkuerr((void __user *)address, pkey);
+ } else {
+ /* XXX: hwpoison faults will set the wrong code. */
+ force_sig_fault(signal, si_code, (void __user *)address);
+ }
}
/*
@@ -798,7 +803,8 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
struct task_struct *tsk = current;
if (!user_mode(regs)) {
- kernelmode_fixup_or_oops(regs, error_code, address, pkey, si_code);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGSEGV, si_code, pkey);
return;
}
@@ -930,7 +936,8 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
{
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
- kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, BUS_ADRERR);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGBUS, BUS_ADRERR, 0);
return;
}
@@ -1396,7 +1403,7 @@ void do_user_addr_fault(struct pt_regs *regs,
*/
if (!user_mode(regs))
kernelmode_fixup_or_oops(regs, error_code, address,
- SIGBUS, BUS_ADRERR);
+ SIGBUS, BUS_ADRERR, 0);
return;
}
@@ -1416,7 +1423,7 @@ void do_user_addr_fault(struct pt_regs *regs,
return;
if (fatal_signal_pending(current) && !user_mode(regs)) {
- kernelmode_fixup_or_oops(regs, error_code, address, 0, 0);
+ kernelmode_fixup_or_oops(regs, error_code, address, 0, 0, 0);
return;
}
@@ -1424,7 +1431,7 @@ void do_user_addr_fault(struct pt_regs *regs,
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
kernelmode_fixup_or_oops(regs, error_code, address,
- SIGSEGV, SEGV_MAPERR);
+ SIGSEGV, SEGV_MAPERR, 0);
return;
}
--
2.32.0
next reply other threads:[~2021-07-28 11:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-28 11:44 Jiashuo Liang [this message]
2021-07-28 17:57 ` [PATCH] x86/fault: Fix wrong signal when vsyscall fails with pkey Dave Hansen
2021-07-29 6:24 ` Jiashuo Liang
2021-07-29 14:02 ` Dave Hansen
2021-08-11 0:58 ` Jiashuo Liang
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=20210728114413.287611-1-liangjs@pku.edu.cn \
--to=liangjs@pku.edu.cn \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.