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Groups > linux.kernel > #1258172
| From | Jiri Slaby <jslaby@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.12 025/123] ARM: 8429/1: disable GCC SRA optimization |
| Date | 2015-10-28 15:30 +0100 |
| Message-ID | <qozTK-3KE-65@gated-at.bofh.it> (permalink) |
| References | <qozqF-3k6-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit a077224fd35b2f7fbc93f14cf67074fc792fbac2 upstream.
While working on the 32-bit ARM port of UEFI, I noticed a strange
corruption in the kernel log. The following snprintf() statement
(in drivers/firmware/efi/efi.c:efi_md_typeattr_format())
snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
was producing the following output in the log:
| | | | | |WB|WT|WC|UC]
| | | | | |WB|WT|WC|UC]
| | | | | |WB|WT|WC|UC]
|RUN| | | | |WB|WT|WC|UC]*
|RUN| | | | |WB|WT|WC|UC]*
| | | | | |WB|WT|WC|UC]
|RUN| | | | |WB|WT|WC|UC]*
| | | | | |WB|WT|WC|UC]
|RUN| | | | | | | |UC]
|RUN| | | | | | | |UC]
As it turns out, this is caused by incorrect code being emitted for
the string() function in lib/vsprintf.c. The following code
if (!(spec.flags & LEFT)) {
while (len < spec.field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
}
for (i = 0; i < len; ++i) {
if (buf < end)
*buf = *s;
++buf; ++s;
}
while (len < spec.field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
when called with len == 0, triggers an issue in the GCC SRA optimization
pass (Scalar Replacement of Aggregates), which handles promotion of signed
struct members incorrectly. This is a known but as yet unresolved issue.
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular
case, it is causing the second while loop to be executed erroneously a
single time, causing the additional space characters to be printed.
So disable the optimization by passing -fno-ipa-sra.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/arm/Makefile | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index db50b626be98..a4254e8ab36c 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -55,6 +55,14 @@ endif
comma = ,
+#
+# The Scalar Replacement of Aggregates (SRA) optimization pass in GCC 4.9 and
+# later may result in code being generated that handles signed short and signed
+# char struct members incorrectly. So disable it.
+# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932)
+#
+KBUILD_CFLAGS += $(call cc-option,-fno-ipa-sra)
+
# This selects which instruction set is used.
# Note that GCC does not numerically define an architecture version
# macro, but instead defines a whole series of macros which makes
--
2.6.2
--
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[PATCH 3.12 001/123] x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 027/123] ARM: dts: omap5-uevm.dts: fix i2c5 pinctrl offsets Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 035/123] arc,hexagon: Delete asm/barrier.h Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 037/123] spi: Fix documentation of spi_alloc_master() Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 029/123] x86/apic: Serialize LVTT and TSC_DEADLINE writes Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 026/123] windfarm: decrement client count when unregistering Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:00 +0100
[PATCH 3.12 021/123] perf stat: Get correct cpu id for print_aggr Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 030/123] x86/platform: Fix Geode LX timekeeping in the generic x86 build Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 031/123] x86/mm: Set NX on gap between __ex_table and rodata Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 033/123] arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 032/123] x86/xen: Support kexec/kdump in HVM guests by doing a soft reset Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
Re: [PATCH 3.12 032/123] x86/xen: Support kexec/kdump in HVM guests by doing a soft reset Luis Henriques <luis.henriques@canonical.com> - 2015-10-28 16:30 +0100
Re: [PATCH 3.12 032/123] x86/xen: Support kexec/kdump in HVM guests by doing a soft reset Jiri Slaby <jslaby@suse.cz> - 2015-10-28 16:40 +0100
[PATCH 3.12 022/123] perf header: Fixup reading of HEADER_NRCPUS feature Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 034/123] arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 025/123] ARM: 8429/1: disable GCC SRA optimization Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 028/123] dmaengine: dw: properly read DWC_PARAMS register Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:30 +0100
[PATCH 3.12 014/123] ARM: 7880/1: Clear the IT state independent of the Thumb-2 mode Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 036/123] sched/core: Fix TASK_DEAD race in finish_task_switch() Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 012/123] s390/3270: redraw screen on unsolicited device end Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 013/123] Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 023/123] hwmon: (nct6775) Swap STEP_UP_TIME and STEP_DOWN_TIME registers for most chips Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 017/123] kvm: fix zero length mmio searching Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 018/123] scsi: fix scsi_error_handler vs. scsi_host_dev_release race Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 002/123] x86/paravirt: Replace the paravirt nop with a bona fide empty function Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 020/123] perf hists: Update the column width for the "srcline" sort key Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 019/123] iser-target: remove command with state ISTATE_REMOVE Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 024/123] ARM: fix Thumb2 signal handling when ARMv6 is enabled Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 016/123] ALSA: hda - Control SPDIF out pin on MacBookPro 11,2 Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 015/123] net: add length argument to skb_copy_and_csum_datagram_iovec Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:40 +0100
[PATCH 3.12 004/123] rcu: Reject memory-order-induced stall-warning false positives Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 005/123] sched: Fix cpu_active_mask/cpu_online_mask race Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 007/123] xhci: rework cycle bit checking for new dequeue pointers Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 006/123] xhci: Workaround for PME stuck issues in Intel xhci Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 009/123] USB: usbtmc: add device quirk for Rigol DS6104 Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
Re: [PATCH 3.12 009/123] USB: usbtmc: add device quirk for Rigol DS6104 Teunis van Beelen <teuniz@gmail.com> - 2015-10-28 16:40 +0100
[PATCH 3.12 008/123] usb: core: Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 010/123] client MUST ignore EncryptionKeyLength if CAP_EXTENDED_SECURITY is set Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 011/123] iommu/amd: Handle integer overflow in dma_ops_area_alloc Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
[PATCH 3.12 003/123] jbd2: avoid infinite loop when destroying aborted journal Jiri Slaby <jslaby@suse.cz> - 2015-10-28 15:50 +0100
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