From: Brian Cain <bcain@quicinc.com>
To: Al Viro <viro@zeniv.linux.org.uk>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-alpha@vger.kernel.org" <linux-alpha@vger.kernel.org>,
"linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>,
"linux-hexagon@vger.kernel.org" <linux-hexagon@vger.kernel.org>,
"linux-m68k@lists.linux-m68k.org"
<linux-m68k@lists.linux-m68k.org>,
Michal Simek <monstr@monstr.eu>,
Dinh Nguyen <dinguyen@kernel.org>,
"openrisc@lists.librecores.org" <openrisc@lists.librecores.org>,
"linux-parisc@vger.kernel.org" <linux-parisc@vger.kernel.org>,
"linux-riscv@lists.infradead.org"
<linux-riscv@lists.infradead.org>,
"sparclinux@vger.kernel.org" <sparclinux@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: RE: [PATCH 02/10] hexagon: fix livelock in uaccess
Date: Fri, 10 Feb 2023 02:59:41 +0000 [thread overview]
Message-ID: <SN6PR02MB4205D40B41246B41EA8FD069B8DE9@SN6PR02MB4205.namprd02.prod.outlook.com> (raw)
In-Reply-To: <Y9l0LyAA3zAGeT51@ZenIV>
> -----Original Message-----
> From: Al Viro <viro@ftp.linux.org.uk> On Behalf Of Al Viro
> Sent: Tuesday, January 31, 2023 2:04 PM
> To: linux-arch@vger.kernel.org
> Cc: linux-alpha@vger.kernel.org; linux-ia64@vger.kernel.org; linux-
> hexagon@vger.kernel.org; linux-m68k@lists.linux-m68k.org; Michal Simek
> <monstr@monstr.eu>; Dinh Nguyen <dinguyen@kernel.org>;
> openrisc@lists.librecores.org; linux-parisc@vger.kernel.org; linux-
> riscv@lists.infradead.org; sparclinux@vger.kernel.org; Linus Torvalds
> <torvalds@linux-foundation.org>
> Subject: [PATCH 02/10] hexagon: fix livelock in uaccess
>
> WARNING: This email originated from outside of Qualcomm. Please be wary of
> any links or attachments, and do not enable macros.
>
> hexagon equivalent of 26178ec11ef3 "x86: mm: consolidate
> VM_FAULT_RETRY handling"
> If e.g. get_user() triggers a page fault and a fatal signal is caught, we might
> end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing
> anything
> to page tables. In such case we must *not* return to the faulting insn -
> that would repeat the entire thing without making any progress; what we
> need
> instead is to treat that as failed (user) memory access.
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> arch/hexagon/mm/vm_fault.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
> index f73c7cbfe326..4b578d02fd01 100644
> --- a/arch/hexagon/mm/vm_fault.c
> +++ b/arch/hexagon/mm/vm_fault.c
> @@ -93,8 +93,11 @@ void do_page_fault(unsigned long address, long cause,
> struct pt_regs *regs)
>
> fault = handle_mm_fault(vma, address, flags, regs);
>
> - if (fault_signal_pending(fault, regs))
> + if (fault_signal_pending(fault, regs)) {
> + if (!user_mode(regs))
> + goto no_context;
> return;
> + }
>
> /* The fault is fully completed (including releasing mmap lock) */
> if (fault & VM_FAULT_COMPLETED)
> --
> 2.30.2
Acked-by: Brian Cain <bcain@quicinc.com>
next prev parent reply other threads:[~2023-02-10 2:59 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-31 20:02 [RFC][PATCHSET] VM_FAULT_RETRY fixes Al Viro
2023-01-31 20:03 ` [PATCH 01/10] alpha: fix livelock in uaccess Al Viro
2023-03-07 0:48 ` patchwork-bot+linux-riscv
2023-01-31 20:03 ` [PATCH 02/10] hexagon: " Al Viro
2023-02-10 2:59 ` Brian Cain [this message]
2023-01-31 20:04 ` [PATCH 03/10] ia64: " Al Viro
2023-01-31 20:04 ` [PATCH 04/10] m68k: " Al Viro
2023-02-05 6:18 ` Finn Thain
2023-02-05 18:51 ` Linus Torvalds
2023-02-07 3:07 ` Finn Thain
2023-02-05 20:39 ` Al Viro
2023-02-05 20:41 ` Linus Torvalds
2023-02-06 12:08 ` Geert Uytterhoeven
2023-01-31 20:05 ` [PATCH 05/10] microblaze: " Al Viro
2023-01-31 20:05 ` [PATCH 06/10] nios2: " Al Viro
2023-01-31 20:06 ` [PATCH 07/10] openrisc: " Al Viro
2023-01-31 20:06 ` [PATCH 08/10] parisc: " Al Viro
2023-02-06 16:58 ` Helge Deller
2023-02-28 17:34 ` Al Viro
2023-02-28 15:22 ` Guenter Roeck
2023-02-28 19:18 ` Michael Schmitz
2023-01-31 20:06 ` [PATCH 09/10] riscv: " Al Viro
2023-02-06 20:06 ` Björn Töpel
2023-02-07 16:11 ` Geert Uytterhoeven
2023-01-31 20:07 ` [PATCH 10/10] sparc: " Al Viro
2023-01-31 20:24 ` [RFC][PATCHSET] VM_FAULT_RETRY fixes Linus Torvalds
2023-01-31 21:10 ` Al Viro
2023-01-31 21:19 ` Linus Torvalds
2023-01-31 21:49 ` Al Viro
2023-02-01 0:00 ` Linus Torvalds
2023-02-01 19:48 ` Peter Xu
2023-02-01 22:18 ` Al Viro
2023-02-02 0:57 ` Al Viro
2023-02-02 22:56 ` Peter Xu
2023-02-04 0:26 ` Al Viro
2023-02-05 5:10 ` Al Viro
2023-02-01 8:21 ` Helge Deller
2023-02-01 19:51 ` Linus Torvalds
2023-02-02 6:58 ` Al Viro
2023-02-02 8:54 ` Michael Cree
2023-02-02 9:56 ` John Paul Adrian Glaubitz
2023-02-02 15:20 ` Al Viro
2023-02-02 20:20 ` Al Viro
2023-02-02 20:34 ` Linus Torvalds
2023-02-01 10:50 ` Mark Rutland
2023-02-06 12:08 ` Geert Uytterhoeven
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