Patch "MIPS: Save static registers before sysmips" has been added to the 4.9-stable tree
Subsystems (2)
This is a note to let you know that I've just added the patch titled
MIPS: Save static registers before sysmips
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-save-static-registers-before-sysmips.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
49955d84cd9ccdca5a16a495e448e1a06fad9e49Mon Sep 17 00:00:00 2001
From: James Hogan <[email protected]>
Date: Wed, 31 May 2017 16:19:48 +0100
Subject: MIPS: Save static registers before sysmips
From: James Hogan <[email protected]>
commit 49955d84cd9ccdca5a16a495e448e1a06fad9e49 upstream.
The MIPS sysmips system call handler may return directly from the MIPS_ATOMIC_SET case (mips_atomic_set()) to syscall_exit. This path restores the static (callee saved) registers, however they won't have been saved on entry to the system call.
Use the save_static_function() macro to create a __sys_sysmips wrapper function which saves the static registers before calling sys_sysmips, so that the correct static register state is restored by syscall_exit.
Patchwork: https://patchwork.linux-mips.org/patch/16149/
--- arch/mips/kernel/scall32-o32.S | 2 +- arch/mips/kernel/scall64-64.S | 2 +- arch/mips/kernel/scall64-n32.S | 2 +- arch/mips/kernel/scall64-o32.S | 2 +- arch/mips/kernel/syscall.c | 6 ++++++ 5 files changed, 10 insertions(+), 4 deletions(-)
arch/mips/kernel/scall32-o32.S +1 -1
@@ -371,7 +371,7 @@ EXPORT(sys_call_table) PTR sys_writev PTR sys_cacheflush PTR sys_cachectl - PTR sys_sysmips + PTR __sys_sysmips PTR sys_ni_syscall /* 4150 */ PTR sys_getsid PTR sys_fdatasync
arch/mips/kernel/scall64-64.S +1 -1
@@ -311,7 +311,7 @@ EXPORT(sys_call_table) PTR sys_sched_getaffinity PTR sys_cacheflush PTR sys_cachectl - PTR sys_sysmips + PTR __sys_sysmips PTR sys_io_setup /* 5200 */ PTR sys_io_destroy PTR sys_io_getevents
arch/mips/kernel/scall64-n32.S +1 -1
@@ -302,7 +302,7 @@ EXPORT(sysn32_call_table) PTR compat_sys_sched_getaffinity PTR sys_cacheflush PTR sys_cachectl - PTR sys_sysmips + PTR __sys_sysmips PTR compat_sys_io_setup /* 6200 */ PTR sys_io_destroy PTR compat_sys_io_getevents
arch/mips/kernel/scall64-o32.S +1 -1
@@ -371,7 +371,7 @@ EXPORT(sys32_call_table) PTR compat_sys_writev PTR sys_cacheflush PTR sys_cachectl - PTR sys_sysmips + PTR __sys_sysmips PTR sys_ni_syscall /* 4150 */ PTR sys_getsid PTR sys_fdatasync
arch/mips/kernel/syscall.c +6 -0
@@ -202,6 +202,12 @@ static inline int mips_atomic_set(unsignunreachable (); } +/* +* mips_atomic_set() normally returns directly via syscall_exit potentially +* clobbering static registers, so be sure to preserve them. +*/ +save_static_function (sys_sysmips); + SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2) {switch (cmd) {
Patches currently in stable-queue which might be from [email protected] are
queue-4.9/mips-send-sigill-for-bposge32-in-__compute_return_epc_for_insn.patch queue-4.9/mips-actually-decode-jalx-in-__compute_return_epc_for_insn.patch queue-4.9/mips-fix-mips_atomic_set-retry-condition.patch queue-4.9/mips-fix-a-typo-s-preset-present-in-r2-to-r6-emulation-error-message.patch queue-4.9/mips-fix-mips_atomic_set-with-eva.patch queue-4.9/mips-save-static-registers-before-sysmips.patch queue-4.9/mips-fix-unaligned-pc-interpretation-in-compute_return_epc.patch queue-4.9/mips-fix-mips-i-isa-proc-cpuinfo-reporting.patch queue-4.9/mips-rename-sigill_r6-to-sigill_r2r6-in-__compute_return_epc_for_insn.patch queue-4.9/mips-negate-error-syscall-return-in-trace.patch queue-4.9/mips-send-sigill-for-r6-branches-in-__compute_return_epc_for_insn.patch queue-4.9/mips-send-sigill-for-linked-branches-in-__compute_return_epc_for_insn.patch queue-4.9/mips-math-emu-prevent-wrong-isa-mode-instruction-emulation.patch