linux-stable.git/arch/sparc/kernel/setup_64.c, branch linux-3.19.y Linux kernel stable tree sparc64: Fix register corruption in top-most kernel stack frame during boot. 2014-10-24T16:52:49+00:00 David S. Miller davem@davemloft.net 2014-10-23T19:58:13+00:00 ef3e035c3a9b81da8a778bc333d10637acf6c199 Meelis Roos reported that kernels built with gcc-4.9 do not boot, we eventually narrowed this down to only impacting machines using UltraSPARC-III and derivitive cpus. The crash happens right when the first user process is spawned: [ 54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 [ 54.451346] [ 54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab #96 [ 54.666431] Call Trace: [ 54.698453] [0000000000762f8c] panic+0xb0/0x224 [ 54.759071] [000000000045cf68] do_exit+0x948/0x960 [ 54.823123] [000000000042cbc0] fault_in_user_windows+0xe0/0x100 [ 54.902036] [0000000000404ad0] __handle_user_windows+0x0/0x10 [ 54.978662] Press Stop-A (L1-A) to return to the boot prom [ 55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 Further investigation showed that compiling only per_cpu_patch() with an older compiler fixes the boot. Detailed analysis showed that the function is not being miscompiled by gcc-4.9, but it is using a different register allocation ordering. With the gcc-4.9 compiled function, something during the code patching causes some of the %i* input registers to get corrupted. Perhaps we have a TLB miss path into the firmware that is deep enough to cause a register window spill and subsequent restore when we get back from the TLB miss trap. Let's plug this up by doing two things: 1) Stop using the firmware stack for client interface calls into the firmware. Just use the kernel's stack. 2) As soon as we can, call into a new function "start_early_boot()" to put a one-register-window buffer between the firmware's deepest stack frame and the top-most initial kernel one. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net> 
Meelis Roos reported that kernels built with gcc-4.9 do not boot, we
eventually narrowed this down to only impacting machines using
UltraSPARC-III and derivitive cpus.

The crash happens right when the first user process is spawned:

[   54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[   54.451346]
[   54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab #96
[   54.666431] Call Trace:
[   54.698453]  [0000000000762f8c] panic+0xb0/0x224
[   54.759071]  [000000000045cf68] do_exit+0x948/0x960
[   54.823123]  [000000000042cbc0] fault_in_user_windows+0xe0/0x100
[   54.902036]  [0000000000404ad0] __handle_user_windows+0x0/0x10
[   54.978662] Press Stop-A (L1-A) to return to the boot prom
[   55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

Further investigation showed that compiling only per_cpu_patch() with
an older compiler fixes the boot.

Detailed analysis showed that the function is not being miscompiled by
gcc-4.9, but it is using a different register allocation ordering.

With the gcc-4.9 compiled function, something during the code patching
causes some of the %i* input registers to get corrupted.  Perhaps
we have a TLB miss path into the firmware that is deep enough to
cause a register window spill and subsequent restore when we get
back from the TLB miss trap.

Let's plug this up by doing two things:

1) Stop using the firmware stack for client interface calls into
   the firmware.  Just use the kernel's stack.

2) As soon as we can, call into a new function "start_early_boot()"
   to put a one-register-window buffer between the firmware's
   deepest stack frame and the top-most initial kernel one.

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
sparc64: mem boot option correction 2014-09-17T01:23:11+00:00 bob picco bpicco@meloft.net 2014-09-16T13:29:54+00:00 7c21d533ab2ffa1e681bdaf4a53ce3046f6e0e17 The "mem" boot option can result in many unexpected consequences. This patch attempts to prevent boot hangs which have been experienced on T4-4 and T5-8. Basically the boot loader allocates vmlinuz and initrd higher in available OBP physical memory. For example, on a 2Tb T5-8 it isn't possible to boot with mem=20G. The patch utilizes memblock to avoid reserved regions and trim memory which is only free. Other improvements are possible for a multi-node machine. This is a snippet of the boot log with mem=20G on T5-8 with the patch applied: MEMBLOCK configuration: <- before memory reduction memory size = 0x1ffad6ce000 reserved size = 0xa1adf44 memory.cnt = 0xb memory[0x0] [0x00000030400000-0x00003fdde47fff], 0x3fada48000 bytes memory[0x1] [0x00003fdde4e000-0x00003fdde4ffff], 0x2000 bytes memory[0x2] [0x00080000000000-0x00083fffffffff], 0x4000000000 bytes memory[0x3] [0x00100000000000-0x00103fffffffff], 0x4000000000 bytes memory[0x4] [0x00180000000000-0x00183fffffffff], 0x4000000000 bytes memory[0x5] [0x00200000000000-0x00203fffffffff], 0x4000000000 bytes memory[0x6] [0x00280000000000-0x00283fffffffff], 0x4000000000 bytes memory[0x7] [0x00300000000000-0x00303fffffffff], 0x4000000000 bytes memory[0x8] [0x00380000000000-0x00383fffc71fff], 0x3fffc72000 bytes memory[0x9] [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes memory[0xa] [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes reserved.cnt = 0x2 reserved[0x0] [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes reserved[0x1] [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes ... MEMBLOCK configuration: <- after reduction of memory memory size = 0x50a1adf44 reserved size = 0xa1adf44 memory.cnt = 0x4 memory[0x0] [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes memory[0x1] [0x00380004000000-0x0038050d01d74a], 0x50901d74b bytes memory[0x2] [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes memory[0x3] [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes reserved.cnt = 0x2 reserved[0x0] [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes reserved[0x1] [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes ... Early memory node ranges node 7: [mem 0x380000000000-0x38000117dfff] node 7: [mem 0x380004000000-0x380f0d01bfff] node 7: [mem 0x383fffc92000-0x383fffca1fff] node 7: [mem 0x383fffcb4000-0x383fffcb5fff] Could not find start_pfn for node 0 Could not find start_pfn for node 1 Could not find start_pfn for node 2 Could not find start_pfn for node 3 Could not find start_pfn for node 4 Could not find start_pfn for node 5 Could not find start_pfn for node 6 . The patch was tested on T4-1, T5-8 and Jalap?no. Cc: sparclinux@vger.kernel.org Signed-off-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The "mem" boot option can result in many unexpected consequences. This patch
attempts to prevent boot hangs which have been experienced on T4-4 and T5-8.
Basically the boot loader allocates vmlinuz and initrd higher in available
OBP physical memory. For example, on a 2Tb T5-8 it isn't possible to boot
with mem=20G.

The patch utilizes memblock to avoid reserved regions and trim memory which
is only free. Other improvements are possible for a multi-node machine.

This is a snippet of the boot log with mem=20G on T5-8 with the patch applied:
MEMBLOCK configuration:	<- before memory reduction
 memory size = 0x1ffad6ce000 reserved size = 0xa1adf44
 memory.cnt  = 0xb
 memory[0x0]    [0x00000030400000-0x00003fdde47fff], 0x3fada48000 bytes
 memory[0x1]    [0x00003fdde4e000-0x00003fdde4ffff], 0x2000 bytes
 memory[0x2]    [0x00080000000000-0x00083fffffffff], 0x4000000000 bytes
 memory[0x3]    [0x00100000000000-0x00103fffffffff], 0x4000000000 bytes
 memory[0x4]    [0x00180000000000-0x00183fffffffff], 0x4000000000 bytes
 memory[0x5]    [0x00200000000000-0x00203fffffffff], 0x4000000000 bytes
 memory[0x6]    [0x00280000000000-0x00283fffffffff], 0x4000000000 bytes
 memory[0x7]    [0x00300000000000-0x00303fffffffff], 0x4000000000 bytes
 memory[0x8]    [0x00380000000000-0x00383fffc71fff], 0x3fffc72000 bytes
 memory[0x9]    [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes
 memory[0xa]    [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes
 reserved.cnt  = 0x2
 reserved[0x0]  [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 reserved[0x1]  [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes
...
MEMBLOCK configuration:	<- after reduction of memory
 memory size = 0x50a1adf44 reserved size = 0xa1adf44
 memory.cnt  = 0x4
 memory[0x0]    [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 memory[0x1]    [0x00380004000000-0x0038050d01d74a], 0x50901d74b bytes
 memory[0x2]    [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes
 memory[0x3]    [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes
 reserved.cnt  = 0x2
 reserved[0x0]  [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 reserved[0x1]  [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes
...
Early memory node ranges
  node   7: [mem 0x380000000000-0x38000117dfff]
  node   7: [mem 0x380004000000-0x380f0d01bfff]
  node   7: [mem 0x383fffc92000-0x383fffca1fff]
  node   7: [mem 0x383fffcb4000-0x383fffcb5fff]
Could not find start_pfn for node 0
Could not find start_pfn for node 1
Could not find start_pfn for node 2
Could not find start_pfn for node 3
Could not find start_pfn for node 4
Could not find start_pfn for node 5
Could not find start_pfn for node 6
.

The patch was tested on T4-1, T5-8 and Jalap?no.

Cc: sparclinux@vger.kernel.org
Signed-off-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sparc64: cpu hardware caps support for sparc M6 and M7 2014-09-09T22:24:10+00:00 Allen Pais allen.pais@oracle.com 2014-09-08T06:18:55+00:00 408316258521168614bfb4da0e070490d3e65a17 Signed-off-by: Allen Pais <allen.pais@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cpu hw caps support for sparc64x 2013-08-01T02:10:03+00:00 Allen Pais allen.pais@oracle.com 2013-07-23T11:20:38+00:00 4e96377983d2e060dd89703f1846ad920af9e17f Signed-off-by: Allen Pais <allen.pais@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sparc: kernel: using strlcpy() instead of strcpy() 2013-06-19T09:10:29+00:00 Zhao Hongjiang zhaohongjiang@huawei.com 2013-06-09T08:57:58+00:00 117a0c5fc9c2d06045bd217385b2b39ea426b5a6 'boot_command_line' and 'full_boot_str' has a fix length, 'cmdline_p' and 'boot_command' maybe larger than them. So use strlcpy() instead of strcpy() to avoid memory overflow. Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
'boot_command_line' and 'full_boot_str' has a fix length, 'cmdline_p' and
'boot_command' maybe larger than them. So use strlcpy() instead of strcpy()
to avoid memory overflow.

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
taint: add explicit flag to show whether lock dep is still OK. 2013-01-21T06:47:57+00:00 Rusty Russell rusty@rustcorp.com.au 2013-01-21T06:47:39+00:00 373d4d099761cb1f637bed488ab3871945882273 Fix up all callers as they were before, with make one change: an unsigned module taints the kernel, but doesn't turn off lockdep. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> 
Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
sparc64: Improvde documentation and readability of atomic backoff code. 2012-10-28T20:04:47+00:00 David S. Miller davem@davemloft.net 2012-10-28T20:04:47+00:00 187818cd6a5ab6343eac47e52da2f3e40c544b98 Document what's going on in asm/backoff.h with a large and descriptive comment. Refer to it above the cpu_relax() definition in asm/processor_64.h Rename the pause patching section to have "3insn" in it's name like the other patching sections do. Based upon feedback from Sam Ravnborg. Signed-off-by: David S. Miller <davem@davemloft.net> 
Document what's going on in asm/backoff.h with a large and descriptive
comment.  Refer to it above the cpu_relax() definition in
asm/processor_64.h

Rename the pause patching section to have "3insn" in it's name like
the other patching sections do.

Based upon feedback from Sam Ravnborg.

Signed-off-by: David S. Miller <davem@davemloft.net>
sparc64: Use pause instruction when available. 2012-10-28T06:00:41+00:00 David S. Miller davem@davemloft.net 2012-10-28T06:00:41+00:00 e9b9eb59ffcdee09ec96b040f85c919618f4043e In atomic backoff and cpu_relax(), use the pause instruction found on SPARC-T4 and later. It makes the cpu strand unselectable for the given number of cycles, unless an intervening disrupting trap occurs. Signed-off-by: David S. Miller <davem@davemloft.net> 
In atomic backoff and cpu_relax(), use the pause instruction
found on SPARC-T4 and later.

It makes the cpu strand unselectable for the given number of
cycles, unless an intervening disrupting trap occurs.

Signed-off-by: David S. Miller <davem@davemloft.net>
sparc64: Add detection for features new in SPARC-T4. 2012-08-19T06:02:36+00:00 David S. Miller davem@davemloft.net 2012-08-16T23:41:04+00:00 6f859c0e96f0737a543610a189d12420c569110f Compare and branch, pause, and the various new cryptographic opcodes. We advertise the crypto opcodes to userspace using one hwcap bit, HWCAP_SPARC_CRYPTO. This essentially indicates that the %cfr register can be interrograted and used to determine exactly which crypto opcodes are available on the current cpu. We use the %cfr register to report all of the crypto opcodes available in the bootup CPU caps log message, and via /proc/cpuinfo. Signed-off-by: David S. Miller <davem@davemloft.net> 
Compare and branch, pause, and the various new cryptographic opcodes.

We advertise the crypto opcodes to userspace using one hwcap bit,
HWCAP_SPARC_CRYPTO.

This essentially indicates that the %cfr register can be interrograted
and used to determine exactly which crypto opcodes are available on
the current cpu.

We use the %cfr register to report all of the crypto opcodes available
in the bootup CPU caps log message, and via /proc/cpuinfo.

Signed-off-by: David S. Miller <davem@davemloft.net>
Disintegrate asm/system.h for Sparc 2012-03-28T17:30:03+00:00 David Howells dhowells@redhat.com 2012-03-28T17:30:03+00:00 d550bbd40c0e10aefa05103dadbe0ae42e683707 Disintegrate asm/system.h for Sparc. Signed-off-by: David Howells <dhowells@redhat.com> cc: sparclinux@vger.kernel.org 
Disintegrate asm/system.h for Sparc.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: sparclinux@vger.kernel.org