From c18df0adabf8400c1825b90382d06df5edc303fa Mon Sep 17 00:00:00 2001
From: David Daney <david.daney@cavium.com>
Date: Tue, 20 Sep 2016 11:46:35 -0700
Subject: [PATCH 1/2] arm64: Call numa_store_cpu_info() earlier.
The wq_numa_init() function makes a private CPU to node map by calling
cpu_to_node() early in the boot process, before the non-boot CPUs are
brought online. Since the default implementation of cpu_to_node()
returns zero for CPUs that have never been brought online, the
workqueue system's view is that *all* CPUs are on node zero.
When the unbound workqueue for a non-zero node is created, the
tsk_cpus_allowed() for the worker threads is the empty set because
there are, in the view of the workqueue system, no CPUs on non-zero
nodes. The code in try_to_wake_up() using this empty cpumask ends up
using the cpumask empty set value of NR_CPUS as an index into the
per-CPU area pointer array, and gets garbage as it is one past the end
of the array. This results in:
[ 0.881970] Unable to handle kernel paging request at virtual address fffffb1008b926a4
[ 1.970095] pgd = fffffc00094b0000
[ 1.973530] [fffffb1008b926a4] *pgd=0000000000000000, *pud=0000000000000000, *pmd=0000000000000000
[ 1.982610] Internal error: Oops: 96000004 [#1] SMP
[ 1.987541] Modules linked in:
[ 1.990631] CPU: 48 PID: 295 Comm: cpuhp/48 Tainted: G W 4.8.0-rc6-preempt-vol+ #9
[ 1.999435] Hardware name: Cavium ThunderX CN88XX board (DT)
[ 2.005159] task: fffffe0fe89cc300 task.stack: fffffe0fe8b8c000
[ 2.011158] PC is at try_to_wake_up+0x194/0x34c
[ 2.015737] LR is at try_to_wake_up+0x150/0x34c
[ 2.020318] pc : [<fffffc00080e7468>] lr : [<fffffc00080e7424>] pstate: 600000c5
[ 2.027803] sp : fffffe0fe8b8fb10
[ 2.031149] x29: fffffe0fe8b8fb10 x28: 0000000000000000
[ 2.036522] x27: fffffc0008c63bc8 x26: 0000000000001000
[ 2.041896] x25: fffffc0008c63c80 x24: fffffc0008bfb200
[ 2.047270] x23: 00000000000000c0 x22: 0000000000000004
[ 2.052642] x21: fffffe0fe89d25bc x20: 0000000000001000
[ 2.058014] x19: fffffe0fe89d1d00 x18: 0000000000000000
[ 2.063386] x17: 0000000000000000 x16: 0000000000000000
[ 2.068760] x15: 0000000000000018 x14: 0000000000000000
[ 2.074133] x13: 0000000000000000 x12: 0000000000000000
[ 2.079505] x11: 0000000000000000 x10: 0000000000000000
[ 2.084879] x9 : 0000000000000000 x8 : 0000000000000000
[ 2.090251] x7 : 0000000000000040 x6 : 0000000000000000
[ 2.095621] x5 : ffffffffffffffff x4 : 0000000000000000
[ 2.100991] x3 : 0000000000000000 x2 : 0000000000000000
[ 2.106364] x1 : fffffc0008be4c24 x0 : ffffff0ffffada80
[ 2.111737]
[ 2.113236] Process cpuhp/48 (pid: 295, stack limit = 0xfffffe0fe8b8c020)
[ 2.120102] Stack: (0xfffffe0fe8b8fb10 to 0xfffffe0fe8b90000)
[ 2.125914] fb00: fffffe0fe8b8fb80 fffffc00080e7648
.
.
.
[ 2.442859] Call trace:
[ 2.445327] Exception stack(0xfffffe0fe8b8f940 to 0xfffffe0fe8b8fa70)
[ 2.451843] f940: fffffe0fe89d1d00 0000040000000000 fffffe0fe8b8fb10 fffffc00080e7468
[ 2.459767] f960: fffffe0fe8b8f980 fffffc00080e4958 ffffff0ff91ab200 fffffc00080e4b64
[ 2.467690] f980: fffffe0fe8b8f9d0 fffffc00080e515c fffffe0fe8b8fa80 0000000000000000
[ 2.475614] f9a0: fffffe0fe8b8f9d0 fffffc00080e58e4 fffffe0fe8b8fa80 0000000000000000
[ 2.483540] f9c0: fffffe0fe8d10000 0000000000000040 fffffe0fe8b8fa50 fffffc00080e5ac4
[ 2.491465] f9e0: ffffff0ffffada80 fffffc0008be4c24 0000000000000000 0000000000000000
[ 2.499387] fa00: 0000000000000000 ffffffffffffffff 0000000000000000 0000000000000040
[ 2.507309] fa20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 2.515233] fa40: 0000000000000000 0000000000000000 0000000000000000 0000000000000018
[ 2.523156] fa60: 0000000000000000 0000000000000000
[ 2.528089] [<fffffc00080e7468>] try_to_wake_up+0x194/0x34c
[ 2.533723] [<fffffc00080e7648>] wake_up_process+0x28/0x34
[ 2.539275] [<fffffc00080d3764>] create_worker+0x110/0x19c
[ 2.544824] [<fffffc00080d69dc>] alloc_unbound_pwq+0x3cc/0x4b0
[ 2.550724] [<fffffc00080d6bcc>] wq_update_unbound_numa+0x10c/0x1e4
[ 2.557066] [<fffffc00080d7d78>] workqueue_online_cpu+0x220/0x28c
[ 2.563234] [<fffffc00080bd288>] cpuhp_invoke_callback+0x6c/0x168
[ 2.569398] [<fffffc00080bdf74>] cpuhp_up_callbacks+0x44/0xe4
[ 2.575210] [<fffffc00080be194>] cpuhp_thread_fun+0x13c/0x148
[ 2.581027] [<fffffc00080dfbac>] smpboot_thread_fn+0x19c/0x1a8
[ 2.586929] [<fffffc00080dbd64>] kthread+0xdc/0xf0
[ 2.591776] [<fffffc0008083380>] ret_from_fork+0x10/0x50
[ 2.597147] Code: b00057e1 91304021 91005021 b8626822 (b8606821)
[ 2.603464] ---[ end trace 58c0cd36b88802bc ]---
[ 2.608138] Kernel panic - not syncing: Fatal exception
Fix by moving call to numa_store_cpu_info() for all CPUs into
smp_prepare_cpus(), which happens before wq_numa_init(). Since
smp_store_cpu_info() now contains only a single function call,
simplify by removing the function and out-lining its contents.
Suggested-by: Robert Richter <rric@kernel.org>
Fixes: 1a2db300348b ("arm64, numa: Add NUMA support for arm64 platforms.")
Cc: <stable@vger.kernel.org> # 4.7.x-
Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Tested-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/kernel/smp.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d93d433525047..3ff173e925823 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -201,12 +201,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
return ret;
}
-static void smp_store_cpu_info(unsigned int cpuid)
-{
- store_cpu_topology(cpuid);
- numa_store_cpu_info(cpuid);
-}
-
/*
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
@@ -254,7 +248,7 @@ asmlinkage void secondary_start_kernel(void)
*/
notify_cpu_starting(cpu);
- smp_store_cpu_info(cpu);
+ store_cpu_topology(cpu);
/*
* OK, now it's safe to let the boot CPU continue. Wait for
@@ -689,10 +683,13 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
{
int err;
unsigned int cpu;
+ unsigned int this_cpu;
init_cpu_topology();
- smp_store_cpu_info(smp_processor_id());
+ this_cpu = smp_processor_id();
+ store_cpu_topology(this_cpu);
+ numa_store_cpu_info(this_cpu);
/*
* If UP is mandated by "nosmp" (which implies "maxcpus=0"), don't set
@@ -719,6 +716,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
continue;
set_cpu_present(cpu, true);
+ numa_store_cpu_info(cpu);
}
}
From 67787b68ec48c239d5ec12f9bf5adaf5c459517a Mon Sep 17 00:00:00 2001
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
Date: Fri, 23 Sep 2016 16:42:08 +0900
Subject: [PATCH 2/2] arm64: kgdb: handle read-only text / modules
Handle read-only cases when CONFIG_DEBUG_RODATA (4.0) or
CONFIG_DEBUG_SET_MODULE_RONX (3.18) are enabled by using
aarch64_insn_write() instead of probe_kernel_write() as introduced by
commit 2f896d586610 ("arm64: use fixmap for text patching") in 4.0.
Fixes: 11d91a770f1f ("arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support")
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/include/asm/debug-monitors.h | 2 --
arch/arm64/kernel/kgdb.c | 36 ++++++++++++++++---------
2 files changed, 24 insertions(+), 14 deletions(-)
diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 4b6b3f72a2158..b71420a12f261 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -61,8 +61,6 @@
#define AARCH64_BREAK_KGDB_DYN_DBG \
(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
-#define KGDB_DYN_BRK_INS_BYTE(x) \
- ((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
#define CACHE_FLUSH_IS_SAFE 1
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index 8c57f6496e56d..e017a9493b92e 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -19,10 +19,13 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/bug.h>
#include <linux/irq.h>
#include <linux/kdebug.h>
#include <linux/kgdb.h>
#include <linux/kprobes.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
#include <asm/traps.h>
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
@@ -338,15 +341,24 @@ void kgdb_arch_exit(void)
unregister_die_notifier(&kgdb_notifier);
}
-/*
- * ARM instructions are always in LE.
- * Break instruction is encoded in LE format
- */
-struct kgdb_arch arch_kgdb_ops = {
- .gdb_bpt_instr = {
- KGDB_DYN_BRK_INS_BYTE(0),
- KGDB_DYN_BRK_INS_BYTE(1),
- KGDB_DYN_BRK_INS_BYTE(2),
- KGDB_DYN_BRK_INS_BYTE(3),
- }
-};
+struct kgdb_arch arch_kgdb_ops;
+
+int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
+{
+ int err;
+
+ BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
+
+ err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
+ if (err)
+ return err;
+
+ return aarch64_insn_write((void *)bpt->bpt_addr,
+ (u32)AARCH64_BREAK_KGDB_DYN_DBG);
+}
+
+int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
+{
+ return aarch64_insn_write((void *)bpt->bpt_addr,
+ *(u32 *)bpt->saved_instr);
+}