From: Willy Tarreau <w@1wt.eu>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ed Swierk <eswierk@skyportsystems.com>,
linux-mips@linux-mips.org, Ralf Baechle <ralf@linux-mips.org>,
Ben Hutchings <ben@decadent.org.uk>, Willy Tarreau <w@1wt.eu>
Subject: [PATCH 2.6.32 37/42] MIPS: Fix restart of indirect syscalls
Date: Sat, 23 Jan 2016 15:12:58 +0100 [thread overview]
Message-ID: <20160123141223.589159555@1wt.eu> (raw)
In-Reply-To: <aa387f55227cb730b41e3d621bf460ff@local>
2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------
From: Ed Swierk <eswierk@skyportsystems.com>
commit e967ef022e00bb7c2e5b1a42007abfdd52055050 upstream.
When 32-bit MIPS userspace invokes a syscall indirectly via syscall(number,
arg1, ..., arg7), the kernel looks up the actual syscall based on the given
number, shifts the other arguments to the left, and jumps to the syscall.
If the syscall is interrupted by a signal and indicates it needs to be
restarted by the kernel (by returning ERESTARTNOINTR for example), the
syscall must be called directly, since the number is no longer the first
argument, and the other arguments are now staged for a direct call.
Before shifting the arguments, store the syscall number in pt_regs->regs[2].
This gets copied temporarily into pt_regs->regs[0] after the syscall returns.
If the syscall needs to be restarted, handle_signal()/do_signal() copies the
number back to pt_regs->reg[2], which ends up in $v0 once control returns to
userspace.
Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8929/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 08f865bba9c705aef95268a33393698e5385587e)
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
arch/mips/kernel/scall32-o32.S | 1 +
arch/mips/kernel/scall64-o32.S | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index b72c554..44194c1 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -194,6 +194,7 @@ illegal_syscall:
sll t1, t0, 3
beqz v0, einval
lw t2, sys_call_table(t1) # syscall routine
+ sw a0, PT_R2(sp) # call routine directly on restart
/* Some syscalls like execve get their arguments from struct pt_regs
and claim zero arguments in the syscall table. Thus we have to
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 33ed571..1f7c01f 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -180,6 +180,7 @@ LEAF(sys32_syscall)
dsll t1, t0, 3
beqz v0, einval
ld t2, sys_call_table(t1) # syscall routine
+ sd a0, PT_R2(sp) # call routine directly on restart
move a0, a1 # shift argument registers
move a1, a2
--
1.7.12.2.21.g234cd45.dirty
next prev parent reply other threads:[~2016-01-23 14:12 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <aa387f55227cb730b41e3d621bf460ff@local>
2016-01-23 14:12 ` [PATCH 2.6.32 01/42] ip6mr: call del_timer_sync() in ip6mr_free_table() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 02/42] isdn_ppp: Add checks for allocation failure in isdn_ppp_open() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 04/42] RDS: fix race condition when sending a message on unbound socket Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 05/42] unix: avoid use-after-free in ep_remove_wait_queue Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 06/42] ext4: Fix null dereference in ext4_fill_super() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 07/42] Revert "net: add length argument to skb_copy_and_csum_datagram_iovec" Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 08/42] udp: properly support MSG_PEEK with truncated buffers Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 09/42] KEYS: Fix race between read and revoke Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 11/42] net: fix warnings in make htmldocs by moving macro definition out of field declaration Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 12/42] bluetooth: Validate socket address length in sco_sock_bind() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 13/42] sctp: translate host order to network order when setting a hmacid Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 14/42] fuse: break infinite loop in fuse_fill_write_pages() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 15/42] fix sysvfs symlinks Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 16/42] vfs: Avoid softlockups with sendfile(2) Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 17/42] ext4: Fix handling of extended tv_sec Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 18/42] nfs: if we have no valid attrs, then dont declare the attribute cache valid Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 19/42] wan/x25: Fix use-after-free in x25_asy_open_tty() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 20/42] ipv4: igmp: Allow removing groups from a removed interface Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 21/42] sched/core: Remove false-positive warning from wake_up_process() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 22/42] ipmi: move timer init to before irq is setup Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 23/42] tcp: initialize tp->copied_seq in case of cross SYN connection Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 24/42] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 25/42] sctp: update the netstamp_needed counter when copying sockets Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 26/42] af_unix: fix a fatal race with bit fields Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 27/42] rfkill: copy the name into the rfkill struct Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 28/42] ses: Fix problems with simple enclosures Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 29/42] ses: fix additional element traversal bug Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 30/42] tty: Fix GPF in flush_to_ldisc() Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 31/42] mISDN: fix a loop count Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 32/42] ser_gigaset: fix deallocation of platform device structure Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 33/42] spi: fix parent-device reference leak Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 34/42] s390/dis: Fix handling of format specifiers Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 35/42] USB: ipaq.c: fix a timeout loop Willy Tarreau
2016-01-23 14:12 ` [PATCH 2.6.32 36/42] USB: fix invalid memory access in hub_activate() Willy Tarreau
2016-01-23 14:12 ` Willy Tarreau [this message]
2016-01-23 14:12 ` [PATCH 2.6.32 38/42] parisc: Fix syscall restarts Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 39/42] ipv6/addrlabel: fix ip6addrlbl_get() Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 40/42] mm/memory_hotplug.c: check for missing sections in test_pages_in_a_zone() Willy Tarreau
2016-01-23 18:13 ` Ben Hutchings
2016-01-23 18:29 ` Willy Tarreau
2016-01-23 19:05 ` Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 41/42] KVM: x86: Reload pit counters for all channels when restoring state Willy Tarreau
2016-01-23 14:13 ` [PATCH 2.6.32 42/42] kvm: x86: only channel 0 of the i8254 is linked to the HPET Willy Tarreau
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