From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Victor Kamensky <kamensky@cisco.com>,
Bruce Ashfield <bruce.ashfield@gmail.com>,
Paul Burton <paulburton@kernel.org>,
linux-mips@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>,
James Hogan <jhogan@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
richard.purdie@linuxfoundation.org,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.4 10/58] mips: vdso: fix 'jalr t9' crash in vdso code
Date: Thu, 5 Mar 2020 12:13:31 -0500 [thread overview]
Message-ID: <20200305171420.29595-10-sashal@kernel.org> (raw)
In-Reply-To: <20200305171420.29595-1-sashal@kernel.org>
From: Victor Kamensky <kamensky@cisco.com>
[ Upstream commit d3f703c4359ff06619b2322b91f69710453e6b6d ]
Observed that when kernel is built with Yocto mips64-poky-linux-gcc,
and mips64-poky-linux-gnun32-gcc toolchain, resulting vdso contains
'jalr t9' instructions in its code and since in vdso case nobody
sets GOT table code crashes when instruction reached. On other hand
observed that when kernel is built mips-poky-linux-gcc toolchain, the
same 'jalr t9' instruction are replaced with PC relative function
calls using 'bal' instructions.
The difference boils down to -mrelax-pic-calls and -mexplicit-relocs
gcc options that gets different default values depending on gcc
target triplets and corresponding binutils. -mrelax-pic-calls got
enabled by default only in mips-poky-linux-gcc case. MIPS binutils
ld relies on R_MIPS_JALR relocation to convert 'jalr t9' into 'bal'
and such relocation is generated only if -mrelax-pic-calls option
is on.
Please note 'jalr t9' conversion to 'bal' can happen only to static
functions. These static PIC calls use mips local GOT entries that
are supposed to be filled with start of DSO value by run-time linker
(missing in VDSO case) and they do not have dynamic relocations.
Global mips GOT entries must have dynamic relocations and they should
be prevented by cmd_vdso_check Makefile rule.
Solution call out -mrelax-pic-calls and -mexplicit-relocs options
explicitly while compiling MIPS vdso code. That would get correct
and consistent between different toolchains behaviour.
Reported-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: richard.purdie@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/vdso/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
index 996a934ece7d6..3fa4bbe1bae53 100644
--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -29,6 +29,7 @@ endif
cflags-vdso := $(ccflags-vdso) \
$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
-O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
+ -mrelax-pic-calls -mexplicit-relocs \
-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
$(call cc-option, -fno-asynchronous-unwind-tables) \
$(call cc-option, -fno-stack-protector)
--
2.20.1
next prev parent reply other threads:[~2020-03-05 17:21 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-05 17:13 [PATCH AUTOSEL 5.4 01/58] ACPI: watchdog: Allow disabling WDAT at boot Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 02/58] HID: apple: Add support for recent firmware on Magic Keyboards Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 03/58] HID: core: fix off-by-one memset in hid_report_raw_event() Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 04/58] HID: core: increase HID report buffer size to 8KiB Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 05/58] HID: hiddev: Fix race in in hiddev_disconnect() Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 06/58] HID: alps: Fix an error handling path in 'alps_input_configured()' Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 07/58] i2c: altera: Fix potential integer overflow Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 08/58] ACPI: watchdog: Set default timeout in probe Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 09/58] HID: i2c-hid: add Trekstor Surfbook E11B to descriptor override Sasha Levin
2020-03-05 17:13 ` Sasha Levin [this message]
2020-08-29 13:08 ` [PATCH AUTOSEL 5.4 10/58] mips: vdso: fix 'jalr t9' crash in vdso code Hauke Mehrtens
2020-08-29 13:56 ` Sasha Levin
2020-08-29 14:37 ` Hauke Mehrtens
2020-08-30 2:23 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 11/58] MIPS: Disable VDSO time functionality on microMIPS Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 12/58] mips: vdso: add build time check that no 'jalr t9' calls left Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 13/58] MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()' Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 14/58] HID: hid-bigbenff: fix general protection fault caused by double kfree Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 15/58] HID: hid-bigbenff: call hid_hw_stop() in case of error Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 16/58] HID: hid-bigbenff: fix race condition for scheduled work during removal Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 17/58] MIPS: vdso: Wrap -mexplicit-relocs in cc-option Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 18/58] selftests/rseq: Fix out-of-tree compilation Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 19/58] tracing: Fix number printing bug in print_synth_event() Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 20/58] nl80211: fix potential leak in AP start Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 21/58] cfg80211: check reg_rule for NULL in handle_channel_custom() Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 22/58] mac80211: Remove a redundant mutex unlock Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 23/58] scsi: libfc: free response frame from GPN_ID Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 24/58] netfilter: ipset: Fix "INFO: rcu detected stall in hash_xxx" reports Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 25/58] netfilter: ipset: Fix forceadd evaluation path Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 26/58] vhost: Check docket sk_family instead of call getname Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 27/58] net: usb: qmi_wwan: restore mtu min/max values after raw_ip switch Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 28/58] hv_netvsc: Fix unwanted wakeup in netvsc_attach() Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 29/58] net: ks8851-ml: Fix IRQ handling and locking Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 30/58] mac80211: rx: avoid RCU list traversal under mutex Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 31/58] net: ll_temac: Fix race condition causing TX hang Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 32/58] net: ll_temac: Add more error handling of dma_map_single() calls Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 33/58] net: ll_temac: Fix RX buffer descriptor handling on GFP_ATOMIC pressure Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 34/58] net: ll_temac: Handle DMA halt condition caused by buffer underrun Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 35/58] blk-mq: insert passthrough request into hctx->dispatch directly Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 36/58] drm/amdgpu: fix memory leak during TDR test(v2) Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 37/58] kbuild: fix DT binding schema rule to detect command line changes Sasha Levin
2020-03-05 17:13 ` [PATCH AUTOSEL 5.4 38/58] kbuild: add dtbs_check to PHONY Sasha Levin
2020-03-05 17:14 ` [PATCH AUTOSEL 5.4 39/58] kbuild: add dt_binding_check to PHONY in a correct place Sasha Levin
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