linux/arch/arm64
Will Deacon a454483137 arm64: fpsimd: Fix copying of FP state from signal frame into task struct
Commit 9de52a755c ("arm64: fpsimd: Fix failure to restore FPSIMD
state after signals") fixed an issue reported in our FPSIMD signal
restore code but inadvertently introduced another issue which tends to
manifest as random SEGVs in userspace.

The problem is that when we copy the struct fpsimd_state from the kernel
stack (populated from the signal frame) into the struct held in the
current thread_struct, we blindly copy uninitialised stack into the
"cpu" field, which means that context-switching of the FP registers is
no longer reliable.

This patch fixes the problem by copying only the user_fpsimd member of
struct fpsimd_state. We should really rework the function prototypes
to take struct user_fpsimd_state * instead, but let's just get this
fixed for now.

Cc: Dave Martin <Dave.Martin@arm.com>
Fixes: 9de52a755c ("arm64: fpsimd: Fix failure to restore FPSIMD state after signals")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-15 16:12:35 +00:00
..
boot Amlogic fixes for v4.15-rc 2017-12-09 20:23:29 -08:00
configs arm64: defconfig: enable CONFIG_GPIO_UNIPHIER 2017-10-30 14:41:54 +01:00
crypto License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
include arm64/sve: Report SVE to userspace via CPUID only if supported 2017-12-14 15:14:30 +00:00
kernel arm64: fpsimd: Fix copying of FP state from signal frame into task struct 2017-12-15 16:12:35 +00:00
kvm arm64: Add software workaround for Falkor erratum 1041 2017-12-12 11:45:19 +00:00
lib arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
mm arm64: fix CONFIG_DEBUG_WX address reporting 2017-12-14 10:18:23 +00:00
net bpf, arm64: implement jiting of BPF_J{LT, LE, SLT, SLE} 2017-08-09 16:53:56 -07:00
xen
Kconfig arm64: Add software workaround for Falkor erratum 1041 2017-12-12 11:45:19 +00:00
Kconfig.debug
Kconfig.platforms ARM: SoC driver updates for v4.15 2017-11-16 16:05:01 -08:00
Makefile arm64: ftrace: emit ftrace-mod.o contents through code 2017-12-01 13:04:59 +00:00