From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, "Maciej W. Rozycki" <macro@mips.com>,
Ralf Baechle <ralf@linux-mips.org>,
linux-mips@linux-mips.org, James Hogan <jhogan@kernel.org>
Subject: [PATCH 4.4 27/37] MIPS: prctl: Disallow FRE without FR with PR_SET_FP_MODE requests
Date: Tue, 5 Jun 2018 19:01:32 +0200 [thread overview]
Message-ID: <20180605170110.460357621@linuxfoundation.org> (raw)
In-Reply-To: <20180605170108.884872354@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Maciej W. Rozycki <macro@mips.com>
commit 28e4213dd331e944e7fca1954a946829162ed9d4 upstream.
Having PR_FP_MODE_FRE (i.e. Config5.FRE) set without PR_FP_MODE_FR (i.e.
Status.FR) is not supported as the lone purpose of Config5.FRE is to
emulate Status.FR=0 handling on FPU hardware that has Status.FR=1
hardwired[1][2]. Also we do not handle this case elsewhere, and assume
throughout our code that TIF_HYBRID_FPREGS and TIF_32BIT_FPREGS cannot
be set both at once for a task, leading to inconsistent behaviour if
this does happen.
Return unsuccessfully then from prctl(2) PR_SET_FP_MODE calls requesting
PR_FP_MODE_FRE to be set with PR_FP_MODE_FR clear. This corresponds to
modes allowed by `mips_set_personality_fp'.
References:
[1] "MIPS Architecture For Programmers, Vol. III: MIPS32 / microMIPS32
Privileged Resource Architecture", Imagination Technologies,
Document Number: MD00090, Revision 6.02, July 10, 2015, Table 9.69
"Config5 Register Field Descriptions", p. 262
[2] "MIPS Architecture For Programmers, Volume III: MIPS64 / microMIPS64
Privileged Resource Architecture", Imagination Technologies,
Document Number: MD00091, Revision 6.03, December 22, 2015, Table
9.72 "Config5 Register Field Descriptions", p. 288
Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/19327/
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/kernel/process.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -680,6 +680,10 @@ int mips_set_process_fp_mode(struct task
if (value & ~known_bits)
return -EOPNOTSUPP;
+ /* Setting FRE without FR is not supported. */
+ if ((value & (PR_FP_MODE_FR | PR_FP_MODE_FRE)) == PR_FP_MODE_FRE)
+ return -EOPNOTSUPP;
+
/* Avoid inadvertently triggering emulation */
if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu &&
!(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64))
next prev parent reply other threads:[~2018-06-05 17:25 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-05 17:01 [PATCH 4.4 00/37] 4.4.136-stable review Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 01/37] arm64: lse: Add early clobbers to some input/output asm operands Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 02/37] powerpc/64s: Clear PCR on boot Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 03/37] USB: serial: cp210x: use tcflag_t to fix incompatible pointer type Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 04/37] sh: New gcc support Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 05/37] xfs: detect agfl count corruption and reset agfl Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 06/37] Revert "ima: limit file hash setting by user to fix and log modes" Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 07/37] Input: elan_i2c_smbus - fix corrupted stack Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 08/37] tracing: Fix crash when freeing instances with event triggers Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 09/37] selinux: KASAN: slab-out-of-bounds in xattr_getsecurity Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 10/37] cfg80211: further limit wiphy names to 64 bytes Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 11/37] rtlwifi: rtl8192cu: Remove variable self-assignment in rf.c Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 12/37] ASoC: Intel: sst: remove redundant variable dma_dev_name Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 13/37] irda: fix overly long udelay() Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 14/37] tcp: avoid integer overflows in tcp_rcv_space_adjust() Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 15/37] i2c: rcar: make sure clocks are on when doing clock calculation Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 16/37] i2c: rcar: rework hw init Greg Kroah-Hartman
2018-06-18 18:46 ` Ben Hutchings
2018-06-25 10:05 ` Fabrizio Castro
2018-06-05 17:01 ` [PATCH 4.4 17/37] i2c: rcar: remove unused IOERROR state Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 18/37] i2c: rcar: remove spinlock Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 19/37] i2c: rcar: refactor setup of a msg Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 20/37] i2c: rcar: init new messages in irq Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 21/37] i2c: rcar: dont issue stop when HW does it automatically Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 22/37] i2c: rcar: check master irqs before slave irqs Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 23/37] i2c: rcar: revoke START request early Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 24/37] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 25/37] iio:kfifo_buf: check for uint overflow Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 26/37] MIPS: ptrace: Fix PTRACE_PEEKUSR requests for 64-bit FGRs Greg Kroah-Hartman
2018-06-05 17:01 ` Greg Kroah-Hartman [this message]
2018-06-05 17:01 ` [PATCH 4.4 28/37] scsi: scsi_transport_srp: Fix shost to rport translation Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 29/37] stm class: Use vmalloc for the master map Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 30/37] hwtracing: stm: fix build error on some arches Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 32/37] Kbuild: change CC_OPTIMIZE_FOR_SIZE definition Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 33/37] fix io_destroy()/aio_complete() race Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 34/37] mm: fix the NULL mapping case in __isolate_lru_page() Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 35/37] sparc64: Add __multi3 for gcc 7.x and later Greg Kroah-Hartman
2018-06-05 17:01 ` [PATCH 4.4 36/37] sparc64: Dont clibber fixed registers in __multi4 Greg Kroah-Hartman
2018-06-05 21:59 ` [PATCH 4.4 00/37] 4.4.136-stable review Shuah Khan
2018-06-06 0:30 ` Nathan Chancellor
2018-06-06 8:19 ` Greg Kroah-Hartman
2018-06-06 11:18 ` Naresh Kamboju
2018-06-06 12:15 ` Greg Kroah-Hartman
2018-06-06 13:28 ` Guenter Roeck
2018-06-06 13:31 ` Greg Kroah-Hartman
2018-06-06 15:01 ` Guenter Roeck
2018-06-06 15:35 ` Greg Kroah-Hartman
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