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From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Ingo Molnar" <mingo@kernel.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH 3.16 17/86] jump_label/x86: Work around asm build bug on older/backported GCCs
Date: Thu, 16 May 2019 16:55:33 +0100 [thread overview]
Message-ID: <lsq.1558022133.153636021@decadent.org.uk> (raw)
In-Reply-To: <lsq.1558022132.52852998@decadent.org.uk>
3.16.68-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra <peterz@infradead.org>
commit d420acd816c07c7be31bd19d09cbcb16e5572fa6 upstream.
Boris reported that gcc version 4.4.4 20100503 (Red Hat
4.4.4-2) fails to build linux-next kernels that have
this fresh commit via the locking tree:
11276d5306b8 ("locking/static_keys: Add a new static_key interface")
The problem appears to be that even though @key and @branch are
compile time constants, it doesn't see the following expression
as an immediate value:
&((char *)key)[branch]
More recent GCCs don't appear to have this problem.
In particular, Red Hat backported the 'asm goto' feature into 4.4,
'normal' 4.4 compilers will not have this feature and thus not
run into this asm.
The workaround is to supply both values to the asm as immediates
and do the addition in asm.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/include/asm/jump_label.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/x86/include/asm/jump_label.h
+++ b/arch/x86/include/asm/jump_label.h
@@ -22,9 +22,9 @@ static __always_inline bool arch_static_
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
- _ASM_PTR "1b, %l[l_yes], %c0 \n\t"
+ _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
".popsection \n\t"
- : : "i" (&((char *)key)[branch]) : : l_yes);
+ : : "i" (key), "i" (branch) : : l_yes);
return false;
l_yes:
@@ -38,9 +38,9 @@ static __always_inline bool arch_static_
"2:\n\t"
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
- _ASM_PTR "1b, %l[l_yes], %c0 \n\t"
+ _ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
".popsection \n\t"
- : : "i" (&((char *)key)[branch]) : : l_yes);
+ : : "i" (key), "i" (branch) : : l_yes);
return false;
l_yes:
next prev parent reply other threads:[~2019-05-16 16:04 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 15:55 [PATCH 3.16 00/86] 3.16.68-rc1 review Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 04/86] MIPS: jump_label.c: Correct the span of the J instruction Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 01/86] x86/cpufeature: Add bug flags to /proc/cpuinfo Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 08/86] jump_label: Allow asm/jump_label.h to be included in assembly Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 07/86] s390/jump label: use different nop instruction Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 10/86] module, jump_label: Fix module locking Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 02/86] module: add within_module() function Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 03/86] jump_label: Fix small typos in the documentation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 09/86] jump_label: Allow jump labels to be used in assembly Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 05/86] MIPS: jump_label.c: Handle the microMIPS J instruction encoding Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 06/86] s390/jump label: add sanity checks Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 75/86] x86/speculation: Move arch_smt_update() call to after mitigation decisions Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 43/86] x86/speculation: Rework SMT state change Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 78/86] x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 68/86] x86/speculation/mds: Conditionally clear CPU buffers on idle entry Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 32/86] x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 63/86] x86/speculation/mds: Add basic bug infrastructure for MDS Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 34/86] x86/speculation: Update the TIF_SSBD comment Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 64/86] x86/speculation/mds: Add BUG_MSBDS_ONLY Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 79/86] cpu/speculation: Add 'mitigations=' cmdline option Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 66/86] x86/speculation/mds: Add mds_clear_cpu_buffers() Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 76/86] x86/speculation/mds: Add SMT warning message Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 21/86] x86/asm: Error out if asm/jump_label.h is included inappropriately Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 51/86] x86/speculation: Avoid __switch_to_xtra() calls Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 45/86] x86/speculation: Mark string arrays const correctly Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 41/86] x86/Kconfig: Select SCHED_SMT if SMP enabled Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 14/86] locking/static_keys: Rework update logic Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 77/86] x86/speculation/mds: Fix comment Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 27/86] x86/speculation: Support Enhanced IBRS on future CPUs Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 38/86] x86/speculation: Disable STIBP when enhanced IBRS is in use Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 31/86] x86/speculation: Apply IBPB more strictly to avoid cross-process data leak Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 33/86] x86/speculation: Propagate information about RSB filling mitigation to sysfs Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 70/86] x86/speculation/l1tf: Document l1tf in sysfs Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 16/86] jump label, locking/static_keys: Update docs Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 81/86] x86/speculation/mds: Add 'mitigations=' support for MDS Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 44/86] x86/speculation: Reorder the spec_v2 code Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 60/86] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 35/86] x86/speculation: Clean up spectre_v2_parse_cmdline() Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 18/86] locking/static_keys: Fix a silly typo Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 80/86] x86/speculation: Support 'mitigations=' cmdline option Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 40/86] x86/speculation: Reorganize speculation control MSRs update Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 30/86] x86/cpu: Sanitize FAM6_ATOM naming Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 58/86] x86/speculation: Add seccomp Spectre v2 user space protection mode Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 39/86] x86/speculation: Rename SSBD update functions Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 50/86] x86/process: Consolidate and simplify switch_to_xtra() code Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 37/86] x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common() Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 82/86] x86/mds: Add MDSUM variant to the MDS documentation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 36/86] x86/speculation: Remove unnecessary ret variable in cpu_show_common() Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 52/86] x86/speculation: Prepare for conditional IBPB in switch_mm() Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 54/86] x86/speculation: Prepare arch_smt_update() for PRCTL mode Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 69/86] x86/speculation/mds: Add mitigation control for MDS Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 28/86] x86/speculation: Simplify the CPU bug detection logic Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 71/86] x86/speculation/mds: Add sysfs reporting for MDS Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 57/86] x86/speculation: Enable prctl mode for spectre_v2_user Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 86/86] x86/bugs: Change L1TF mitigation string to match upstream Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 59/86] x86/speculation: Provide IBPB always command line options Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 48/86] x86/speculation: Add command line control for indirect branch speculation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 83/86] Documentation: Correct the possible MDS sysfs values Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 23/86] x86/headers: Don't include asm/processor.h in asm/atomic.h Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 22/86] x86/asm: Add asm macros for static keys/jump labels Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 29/86] x86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 74/86] Documentation: Add MDS vulnerability documentation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 24/86] x86/cpufeature: Carve out X86_FEATURE_* Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 62/86] x86/speculation: Consolidate CPU whitelists Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 73/86] Documentation: Move L1TF to separate directory Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 19/86] locking/static_keys: Fix up the static keys documentation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 15/86] locking/static_keys: Add a new static_key interface Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 49/86] x86/speculation: Prepare for per task indirect branch speculation control Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 46/86] x86/speculataion: Mark command line parser data __initdata Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 53/86] x86/speculation: Split out TIF update Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 11/86] jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 85/86] x86/cpu/bugs: Use __initconst for 'const' init data Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 13/86] jump_label: Add jump_entry_key() helper Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 61/86] x86/msr-index: Cleanup bit defines Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 55/86] x86/speculation: Prevent stale SPEC_CTRL msr content Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 84/86] x86/speculation/mds: Fix documentation typo Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 67/86] x86/speculation/mds: Clear CPU buffers on exit to user Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 65/86] x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 56/86] x86/speculation: Add prctl() control for indirect branch speculation Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 12/86] jump_label, locking/static_keys: Rename JUMP_LABEL_TYPE_* and related helpers to the static_key* pattern Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 47/86] x86/speculation: Unify conditional spectre v2 print functions Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 26/86] locking/static_keys: Provide DECLARE and well as DEFINE macros Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 25/86] locking/static_key: Fix concurrent static_key_slow_inc() Ben Hutchings
2019-05-16 15:55 ` Ben Hutchings [this message]
2019-05-16 15:55 ` [PATCH 3.16 20/86] jump_label: make static_key_enabled() work on static_key_true/false types too Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 72/86] x86/speculation/mds: Add mitigation mode VMWERV Ben Hutchings
2019-05-16 15:55 ` [PATCH 3.16 42/86] sched: Add sched_smt_active() Ben Hutchings
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