linux-toradex.git/arch, branch v4.9.27 Linux kernel for Apalis and Colibri modules ftrace/x86: Fix triple fault with graph tracing and suspend-to-ram 2017-05-03T15:36:39+00:00 Josh Poimboeuf jpoimboe@redhat.com 2017-04-13T22:53:55+00:00 6d10a6cfe85e86f6cc48fbd2e0a8ef6efbc9f9c9 commit 34a477e5297cbaa6ecc6e17c042a866e1cbe80d6 upstream. On x86-32, with CONFIG_FIRMWARE and multiple CPUs, if you enable function graph tracing and then suspend to RAM, it will triple fault and reboot when it resumes. The first fault happens when booting a secondary CPU: startup_32_smp() load_ucode_ap() prepare_ftrace_return() ftrace_graph_is_dead() (accesses 'kill_ftrace_graph') The early head_32.S code calls into load_ucode_ap(), which has an an ftrace hook, so it calls prepare_ftrace_return(), which calls ftrace_graph_is_dead(), which tries to access the global 'kill_ftrace_graph' variable with a virtual address, causing a fault because the CPU is still in real mode. The fix is to add a check in prepare_ftrace_return() to make sure it's running in protected mode before continuing. The check makes sure the stack pointer is a virtual kernel address. It's a bit of a hack, but it's not very intrusive and it works well enough. For reference, here are a few other (more difficult) ways this could have potentially been fixed: - Move startup_32_smp()'s call to load_ucode_ap() down to *after* paging is enabled. (No idea what that would break.) - Track down load_ucode_ap()'s entire callee tree and mark all the functions 'notrace'. (Probably not realistic.) - Pause graph tracing in ftrace_suspend_notifier_call() or bringup_cpu() or __cpu_up(), and ensure that the pause facility can be queried from real mode. Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net> Cc: linux-acpi@vger.kernel.org Cc: Borislav Petkov <bp@alien8.de> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/5c1272269a580660703ed2eccf44308e790c7a98.1492123841.git.jpoimboe@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 34a477e5297cbaa6ecc6e17c042a866e1cbe80d6 upstream.

On x86-32, with CONFIG_FIRMWARE and multiple CPUs, if you enable function
graph tracing and then suspend to RAM, it will triple fault and reboot when
it resumes.

The first fault happens when booting a secondary CPU:

startup_32_smp()
  load_ucode_ap()
    prepare_ftrace_return()
      ftrace_graph_is_dead()
        (accesses 'kill_ftrace_graph')

The early head_32.S code calls into load_ucode_ap(), which has an an
ftrace hook, so it calls prepare_ftrace_return(), which calls
ftrace_graph_is_dead(), which tries to access the global
'kill_ftrace_graph' variable with a virtual address, causing a fault
because the CPU is still in real mode.

The fix is to add a check in prepare_ftrace_return() to make sure it's
running in protected mode before continuing.  The check makes sure the
stack pointer is a virtual kernel address.  It's a bit of a hack, but
it's not very intrusive and it works well enough.

For reference, here are a few other (more difficult) ways this could
have potentially been fixed:

- Move startup_32_smp()'s call to load_ucode_ap() down to *after* paging
  is enabled.  (No idea what that would break.)

- Track down load_ucode_ap()'s entire callee tree and mark all the
  functions 'notrace'.  (Probably not realistic.)

- Pause graph tracing in ftrace_suspend_notifier_call() or bringup_cpu()
  or __cpu_up(), and ensure that the pause facility can be queried from
  real mode.

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: linux-acpi@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/5c1272269a580660703ed2eccf44308e790c7a98.1492123841.git.jpoimboe@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARCv2: save r30 on kernel entry as gcc uses it for code-gen 2017-05-03T15:36:39+00:00 Vineet Gupta vgupta@synopsys.com 2017-01-09T03:45:48+00:00 9cbf4337a51dfc886e15a526cb47660404eb2a61 commit ecd43afdbe72017aefe48080631eb625e177ef4d upstream. This is not exposed to userspace debugers yet, which can be done independently as a seperate patch ! Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ecd43afdbe72017aefe48080631eb625e177ef4d upstream.

This is not exposed to userspace debugers yet, which can be done
independently as a seperate patch !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: Avoid BUG warning in arch_check_elf 2017-05-03T15:36:38+00:00 James Cowgill James.Cowgill@imgtec.com 2017-04-11T12:51:07+00:00 92f0ddece7dabeb47a7ce0ecf3f67c1e6fea1cf8 commit c46f59e90226fa5bfcc83650edebe84ae47d454b upstream. arch_check_elf contains a usage of current_cpu_data that will call smp_processor_id() with preemption enabled and therefore triggers a "BUG: using smp_processor_id() in preemptible" warning when an fpxx executable is loaded. As a follow-up to commit b244614a60ab ("MIPS: Avoid a BUG warning during prctl(PR_SET_FP_MODE, ...)"), apply the same fix to arch_check_elf by using raw_current_cpu_data instead. The rationale quoted from the previous commit: "It is assumed throughout the kernel that if any CPU has an FPU, then all CPUs would have an FPU as well, so it is safe to perform the check with preemption enabled - change the code to use raw_ variant of the check to avoid the warning." Fixes: 46490b572544 ("MIPS: kernel: elf: Improve the overall ABI and FPU mode checks") Signed-off-by: James Cowgill <James.Cowgill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15951/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c46f59e90226fa5bfcc83650edebe84ae47d454b upstream.

arch_check_elf contains a usage of current_cpu_data that will call
smp_processor_id() with preemption enabled and therefore triggers a
"BUG: using smp_processor_id() in preemptible" warning when an fpxx
executable is loaded.

As a follow-up to commit b244614a60ab ("MIPS: Avoid a BUG warning during
prctl(PR_SET_FP_MODE, ...)"), apply the same fix to arch_check_elf by
using raw_current_cpu_data instead. The rationale quoted from the previous
commit:

"It is assumed throughout the kernel that if any CPU has an FPU, then
all CPUs would have an FPU as well, so it is safe to perform the check
with preemption enabled - change the code to use raw_ variant of the
check to avoid the warning."

Fixes: 46490b572544 ("MIPS: kernel: elf: Improve the overall ABI and FPU mode checks")
Signed-off-by: James Cowgill <James.Cowgill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15951/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: cevt-r4k: Fix out-of-bounds array access 2017-05-03T15:36:38+00:00 James Hogan james.hogan@imgtec.com 2017-04-05T15:32:45+00:00 6fbb6c02df304dffbadd020e0c0acbbc61ce79ab commit 9d7f29cdb4ca53506115cf1d7a02ce6013894df0 upstream. calculate_min_delta() may incorrectly access a 4th element of buf2[] which only has 3 elements. This may trigger undefined behaviour and has been reported to cause strange crashes in start_kernel() sometime after timer initialization when built with GCC 5.3, possibly due to register/stack corruption: sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 10737418237ns CPU 0 Unable to handle kernel paging request at virtual address ffffb0aa, epc == 8067daa8, ra == 8067da84 Oops[#1]: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #51 task: 8065e3e0 task.stack: 80644000 $ 0 : 00000000 00000001 00000000 00000000 $ 4 : 8065b4d0 00000000 805d0000 00000010 $ 8 : 00000010 80321400 fffff000 812de408 $12 : 00000000 00000000 00000000 ffffffff $16 : 00000002 ffffffff 80660000 806a666c $20 : 806c0000 00000000 00000000 00000000 $24 : 00000000 00000010 $28 : 80644000 80645ed0 00000000 8067da84 Hi : 00000000 Lo : 00000000 epc : 8067daa8 start_kernel+0x33c/0x500 ra : 8067da84 start_kernel+0x318/0x500 Status: 11000402 KERNEL EXL Cause : 4080040c (ExcCode 03) BadVA : ffffb0aa PrId : 0501992c (MIPS 1004Kc) Modules linked in: Process swapper/0 (pid: 0, threadinfo=80644000, task=8065e3e0, tls=00000000) Call Trace: [<8067daa8>] start_kernel+0x33c/0x500 Code: 24050240 0c0131f9 24849c64 <a200b0a8> 41606020 000000c0 0c1a45e6 00000000 0c1a5f44 UBSAN also detects the same issue: ================================================================ UBSAN: Undefined behaviour in arch/mips/kernel/cevt-r4k.c:85:41 load of address 80647e4c with insufficient space for an object of type 'unsigned int' CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #47 Call Trace: [<80028f70>] show_stack+0x88/0xa4 [<80312654>] dump_stack+0x84/0xc0 [<8034163c>] ubsan_epilogue+0x14/0x50 [<803417d8>] __ubsan_handle_type_mismatch+0x160/0x168 [<8002dab0>] r4k_clockevent_init+0x544/0x764 [<80684d34>] time_init+0x18/0x90 [<8067fa5c>] start_kernel+0x2f0/0x500 ================================================================= buf2[] is intentionally only 3 elements so that the last element is the median once 5 samples have been inserted, so explicitly prevent the possibility of comparing against the 4th element rather than extending the array. Fixes: 1fa405552e33f2 ("MIPS: cevt-r4k: Dynamically calculate min_delta_ns") Reported-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Tested-by: Rabin Vincent <rabinv@axis.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15892/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9d7f29cdb4ca53506115cf1d7a02ce6013894df0 upstream.

calculate_min_delta() may incorrectly access a 4th element of buf2[]
which only has 3 elements. This may trigger undefined behaviour and has
been reported to cause strange crashes in start_kernel() sometime after
timer initialization when built with GCC 5.3, possibly due to
register/stack corruption:

sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 10737418237ns
CPU 0 Unable to handle kernel paging request at virtual address ffffb0aa, epc == 8067daa8, ra == 8067da84
Oops[#1]:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #51
task: 8065e3e0 task.stack: 80644000
$ 0   : 00000000 00000001 00000000 00000000
$ 4   : 8065b4d0 00000000 805d0000 00000010
$ 8   : 00000010 80321400 fffff000 812de408
$12   : 00000000 00000000 00000000 ffffffff
$16   : 00000002 ffffffff 80660000 806a666c
$20   : 806c0000 00000000 00000000 00000000
$24   : 00000000 00000010
$28   : 80644000 80645ed0 00000000 8067da84
Hi    : 00000000
Lo    : 00000000
epc   : 8067daa8 start_kernel+0x33c/0x500
ra    : 8067da84 start_kernel+0x318/0x500
Status: 11000402 KERNEL EXL
Cause : 4080040c (ExcCode 03)
BadVA : ffffb0aa
PrId  : 0501992c (MIPS 1004Kc)
Modules linked in:
Process swapper/0 (pid: 0, threadinfo=80644000, task=8065e3e0, tls=00000000)
Call Trace:
[<8067daa8>] start_kernel+0x33c/0x500
Code: 24050240  0c0131f9  24849c64 <a200b0a8> 41606020  000000c0  0c1a45e6 00000000  0c1a5f44

UBSAN also detects the same issue:

================================================================
UBSAN: Undefined behaviour in arch/mips/kernel/cevt-r4k.c:85:41
load of address 80647e4c with insufficient space
for an object of type 'unsigned int'
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #47
Call Trace:
[<80028f70>] show_stack+0x88/0xa4
[<80312654>] dump_stack+0x84/0xc0
[<8034163c>] ubsan_epilogue+0x14/0x50
[<803417d8>] __ubsan_handle_type_mismatch+0x160/0x168
[<8002dab0>] r4k_clockevent_init+0x544/0x764
[<80684d34>] time_init+0x18/0x90
[<8067fa5c>] start_kernel+0x2f0/0x500
=================================================================

buf2[] is intentionally only 3 elements so that the last element is the
median once 5 samples have been inserted, so explicitly prevent the
possibility of comparing against the 4th element rather than extending
the array.

Fixes: 1fa405552e33f2 ("MIPS: cevt-r4k: Dynamically calculate min_delta_ns")
Reported-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Tested-by: Rabin Vincent <rabinv@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15892/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: KGDB: Use kernel context for sleeping threads 2017-05-03T15:36:38+00:00 James Hogan james.hogan@imgtec.com 2017-03-30T15:06:02+00:00 4805f8a8a2f6add254c112efa1aba74c09f81b54 commit 162b270c664dca2e0944308e92f9fcc887151a72 upstream. KGDB is a kernel debug stub and it can't be used to debug userland as it can only safely access kernel memory. On MIPS however KGDB has always got the register state of sleeping processes from the userland register context at the beginning of the kernel stack. This is meaningless for kernel threads (which never enter userland), and for user threads it prevents the user seeing what it is doing while in the kernel: (gdb) info threads Id Target Id Frame ... 3 Thread 2 (kthreadd) 0x0000000000000000 in ?? () 2 Thread 1 (init) 0x000000007705c4b4 in ?? () 1 Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201 Get the register state instead from the (partial) kernel register context stored in the task's thread_struct for resume() to restore. All threads now correctly appear to be in context_switch(): (gdb) info threads Id Target Id Frame ... 3 Thread 2 (kthreadd) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903 2 Thread 1 (init) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903 1 Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201 Call clobbered registers which aren't saved and exception registers (BadVAddr & Cause) which can't be easily determined without stack unwinding are reported as 0. The PC is taken from the return address, such that the state presented matches that found immediately after returning from resume(). Fixes: 8854700115ec ("[MIPS] kgdb: add arch support for the kernel's kgdb core") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15829/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 162b270c664dca2e0944308e92f9fcc887151a72 upstream.

KGDB is a kernel debug stub and it can't be used to debug userland as it
can only safely access kernel memory.

On MIPS however KGDB has always got the register state of sleeping
processes from the userland register context at the beginning of the
kernel stack. This is meaningless for kernel threads (which never enter
userland), and for user threads it prevents the user seeing what it is
doing while in the kernel:

(gdb) info threads
  Id   Target Id         Frame
  ...
  3    Thread 2 (kthreadd) 0x0000000000000000 in ?? ()
  2    Thread 1 (init)   0x000000007705c4b4 in ?? ()
  1    Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201

Get the register state instead from the (partial) kernel register
context stored in the task's thread_struct for resume() to restore. All
threads now correctly appear to be in context_switch():

(gdb) info threads
  Id   Target Id         Frame
  ...
  3    Thread 2 (kthreadd) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903
  2    Thread 1 (init)   context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903
  1    Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201

Call clobbered registers which aren't saved and exception registers
(BadVAddr & Cause) which can't be easily determined without stack
unwinding are reported as 0. The PC is taken from the return address,
such that the state presented matches that found immediately after
returning from resume().

Fixes: 8854700115ec ("[MIPS] kgdb: add arch support for the kernel's kgdb core")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15829/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: [plat-eznps] Fix build error 2017-05-03T15:36:38+00:00 Noam Camus noamca@mellanox.com 2017-04-04T08:00:41+00:00 563300b9ff7f32d02581b366ff63573ad6daf25c commit 6492f09e864417d382e22b922ae30693a7ce2982 upstream. Make ATOMIC_INIT available for all ARC platforms (including plat-eznps) Signed-off-by: Noam Camus <noamca@mellanox.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6492f09e864417d382e22b922ae30693a7ce2982 upstream.

Make ATOMIC_INIT available for all ARC platforms (including plat-eznps)

Signed-off-by: Noam Camus <noamca@mellanox.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc64: Fix kernel panic due to erroneous #ifdef surrounding pmd_write() 2017-05-03T15:36:34+00:00 Tom Hromatka tom.hromatka@oracle.com 2017-03-31T22:31:42+00:00 512d211207df2a6e7ef0fa5c402f0f9f39b1fe8d [ Upstream commit 9ae34dbd8afd790cb5f52467e4f816434379eafa ] This commit moves sparc64's prototype of pmd_write() outside of the CONFIG_TRANSPARENT_HUGEPAGE ifdef. In 2013, commit a7b9403f0e6d ("sparc64: Encode huge PMDs using PTE encoding.") exposed a path where pmd_write() could be called without CONFIG_TRANSPARENT_HUGEPAGE defined. This can result in the panic below. The diff is awkward to read, but the changes are straightforward. pmd_write() was moved outside of #ifdef CONFIG_TRANSPARENT_HUGEPAGE. Also, __HAVE_ARCH_PMD_WRITE was defined. kernel BUG at include/asm-generic/pgtable.h:576! \|/ ____ \|/ "@'/ .. \`@" /_| \__/ |_\ \__U_/ oracle_8114_cdb(8114): Kernel bad sw trap 5 [#1] CPU: 120 PID: 8114 Comm: oracle_8114_cdb Not tainted 4.1.12-61.7.1.el6uek.rc1.sparc64 #1 task: fff8400700a24d60 ti: fff8400700bc4000 task.ti: fff8400700bc4000 TSTATE: 0000004411e01607 TPC: 00000000004609f8 TNPC: 00000000004609fc Y: 00000005 Not tainted TPC: <gup_huge_pmd+0x198/0x1e0> g0: 000000000001c000 g1: 0000000000ef3954 g2: 0000000000000000 g3: 0000000000000001 g4: fff8400700a24d60 g5: fff8001fa5c10000 g6: fff8400700bc4000 g7: 0000000000000720 o0: 0000000000bc5058 o1: 0000000000000240 o2: 0000000000006000 o3: 0000000000001c00 o4: 0000000000000000 o5: 0000048000080000 sp: fff8400700bc6ab1 ret_pc: 00000000004609f0 RPC: <gup_huge_pmd+0x190/0x1e0> l0: fff8400700bc74fc l1: 0000000000020000 l2: 0000000000002000 l3: 0000000000000000 l4: fff8001f93250950 l5: 000000000113f800 l6: 0000000000000004 l7: 0000000000000000 i0: fff8400700ca46a0 i1: bd0000085e800453 i2: 000000026a0c4000 i3: 000000026a0c6000 i4: 0000000000000001 i5: fff800070c958de8 i6: fff8400700bc6b61 i7: 0000000000460dd0 I7: <gup_pud_range+0x170/0x1a0> Call Trace: [0000000000460dd0] gup_pud_range+0x170/0x1a0 [0000000000460e84] get_user_pages_fast+0x84/0x120 [00000000006f5a18] iov_iter_get_pages+0x98/0x240 [00000000005fa744] do_direct_IO+0xf64/0x1e00 [00000000005fbbc0] __blockdev_direct_IO+0x360/0x15a0 [00000000101f74fc] ext4_ind_direct_IO+0xdc/0x400 [ext4] [00000000101af690] ext4_ext_direct_IO+0x1d0/0x2c0 [ext4] [00000000101af86c] ext4_direct_IO+0xec/0x220 [ext4] [0000000000553bd4] generic_file_read_iter+0x114/0x140 [00000000005bdc2c] __vfs_read+0xac/0x100 [00000000005bf254] vfs_read+0x54/0x100 [00000000005bf368] SyS_pread64+0x68/0x80 Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 9ae34dbd8afd790cb5f52467e4f816434379eafa ]

This commit moves sparc64's prototype of pmd_write() outside
of the CONFIG_TRANSPARENT_HUGEPAGE ifdef.

In 2013, commit a7b9403f0e6d ("sparc64: Encode huge PMDs using PTE
encoding.") exposed a path where pmd_write() could be called without
CONFIG_TRANSPARENT_HUGEPAGE defined.  This can result in the panic below.

The diff is awkward to read, but the changes are straightforward.
pmd_write() was moved outside of #ifdef CONFIG_TRANSPARENT_HUGEPAGE.
Also, __HAVE_ARCH_PMD_WRITE was defined.

kernel BUG at include/asm-generic/pgtable.h:576!
              \|/ ____ \|/
              "@'/ .. \`@"
              /_| \__/ |_\
                 \__U_/
oracle_8114_cdb(8114): Kernel bad sw trap 5 [#1]
CPU: 120 PID: 8114 Comm: oracle_8114_cdb Not tainted
4.1.12-61.7.1.el6uek.rc1.sparc64 #1
task: fff8400700a24d60 ti: fff8400700bc4000 task.ti: fff8400700bc4000
TSTATE: 0000004411e01607 TPC: 00000000004609f8 TNPC: 00000000004609fc Y:
00000005    Not tainted
TPC: <gup_huge_pmd+0x198/0x1e0>
g0: 000000000001c000 g1: 0000000000ef3954 g2: 0000000000000000 g3: 0000000000000001
g4: fff8400700a24d60 g5: fff8001fa5c10000 g6: fff8400700bc4000 g7: 0000000000000720
o0: 0000000000bc5058 o1: 0000000000000240 o2: 0000000000006000 o3: 0000000000001c00
o4: 0000000000000000 o5: 0000048000080000 sp: fff8400700bc6ab1 ret_pc: 00000000004609f0
RPC: <gup_huge_pmd+0x190/0x1e0>
l0: fff8400700bc74fc l1: 0000000000020000 l2: 0000000000002000 l3: 0000000000000000
l4: fff8001f93250950 l5: 000000000113f800 l6: 0000000000000004 l7: 0000000000000000
i0: fff8400700ca46a0 i1: bd0000085e800453 i2: 000000026a0c4000 i3: 000000026a0c6000
i4: 0000000000000001 i5: fff800070c958de8 i6: fff8400700bc6b61 i7: 0000000000460dd0
I7: <gup_pud_range+0x170/0x1a0>
Call Trace:
 [0000000000460dd0] gup_pud_range+0x170/0x1a0
 [0000000000460e84] get_user_pages_fast+0x84/0x120
 [00000000006f5a18] iov_iter_get_pages+0x98/0x240
 [00000000005fa744] do_direct_IO+0xf64/0x1e00
 [00000000005fbbc0] __blockdev_direct_IO+0x360/0x15a0
 [00000000101f74fc] ext4_ind_direct_IO+0xdc/0x400 [ext4]
 [00000000101af690] ext4_ext_direct_IO+0x1d0/0x2c0 [ext4]
 [00000000101af86c] ext4_direct_IO+0xec/0x220 [ext4]
 [0000000000553bd4] generic_file_read_iter+0x114/0x140
 [00000000005bdc2c] __vfs_read+0xac/0x100
 [00000000005bf254] vfs_read+0x54/0x100
 [00000000005bf368] SyS_pread64+0x68/0x80

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc64: kern_addr_valid regression 2017-05-03T15:36:34+00:00 bob picco bob.picco@oracle.com 2017-03-10T19:31:19+00:00 24870a79dad693214b21558388cb04dad6159aa3 [ Upstream commit adfae8a5d833fa2b46577a8081f350e408851f5b ] I encountered this bug when using /proc/kcore to examine the kernel. Plus a coworker inquired about debugging tools. We computed pa but did not use it during the maximum physical address bits test. Instead we used the identity mapped virtual address which will always fail this test. I believe the defect came in here: [bpicco@zareason linus.git]$ git describe --contains bb4e6e85daa52 v3.18-rc1~87^2~4 . Signed-off-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit adfae8a5d833fa2b46577a8081f350e408851f5b ]

I encountered this bug when using /proc/kcore to examine the kernel. Plus a
coworker inquired about debugging tools. We computed pa but did
not use it during the maximum physical address bits test. Instead we used
the identity mapped virtual address which will always fail this test.

I believe the defect came in here:
[bpicco@zareason linus.git]$ git describe --contains bb4e6e85daa52
v3.18-rc1~87^2~4
.

Signed-off-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/mce: Make the MCE notifier a blocking one 2017-04-27T07:10:39+00:00 Vishal Verma vishal.l.verma@intel.com 2017-04-18T18:42:35+00:00 f8bc0881fe95496ddf3f8a16808d9860db207941 commit 0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2 upstream. The NFIT MCE handler callback (for handling media errors on NVDIMMs) takes a mutex to add the location of a memory error to a list. But since the notifier call chain for machine checks (x86_mce_decoder_chain) is atomic, we get a lockdep splat like: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0 [..] Call Trace: dump_stack ___might_sleep __might_sleep mutex_lock_nested ? __lock_acquire nfit_handle_mce notifier_call_chain atomic_notifier_call_chain ? atomic_notifier_call_chain mce_gen_pool_process Convert the notifier to a blocking one which gets to run only in process context. Boris: remove the notifier call in atomic context in print_mce(). For now, let's print the MCE on the atomic path so that we can make sure they go out and get logged at least. Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error") Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2 upstream.

The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
  in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
  [..]
  Call Trace:
   dump_stack
   ___might_sleep
   __might_sleep
   mutex_lock_nested
   ? __lock_acquire
   nfit_handle_mce
   notifier_call_chain
   atomic_notifier_call_chain
   ? atomic_notifier_call_chain
   mce_gen_pool_process

Convert the notifier to a blocking one which gets to run only in process
context.

Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.

Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs 2017-04-27T07:10:38+00:00 Yazen Ghannam yazen.ghannam@amd.com 2017-03-30T11:17:14+00:00 6966a6579e1bc7b3486bed395e7d6875912a9a9b commit 29f72ce3e4d18066ec75c79c857bee0618a3504b upstream. MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name. However, MCA bank 3 is defined on Fam17h systems and can be accessed using legacy MSRs. Without a name we get a stack trace on Fam17h systems when trying to register sysfs files for bank 3 on kernels that don't recognize Scalable MCA. Call MCA bank 3 "decode_unit" since this is what it represents on Fam17h. This will allow kernels without SMCA support to see this bank on Fam17h+ and prevent the stack trace. This will not affect older systems since this bank is reserved on them, i.e. it'll be ignored. Tested on AMD Fam15h and Fam17h systems. WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal kobject: (ffff88085bb256c0): attempted to be registered with empty name! ... Call Trace: kobject_add_internal kobject_add kobject_create_and_add threshold_create_device threshold_init_device Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 29f72ce3e4d18066ec75c79c857bee0618a3504b upstream.

MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name.
However, MCA bank 3 is defined on Fam17h systems and can be accessed
using legacy MSRs. Without a name we get a stack trace on Fam17h systems
when trying to register sysfs files for bank 3 on kernels that don't
recognize Scalable MCA.

Call MCA bank 3 "decode_unit" since this is what it represents on
Fam17h. This will allow kernels without SMCA support to see this bank on
Fam17h+ and prevent the stack trace. This will not affect older systems
since this bank is reserved on them, i.e. it'll be ignored.

Tested on AMD Fam15h and Fam17h systems.

  WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal
  kobject: (ffff88085bb256c0): attempted to be registered with empty name!
  ...
  Call Trace:
   kobject_add_internal
   kobject_add
   kobject_create_and_add
   threshold_create_device
   threshold_init_device

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>