linux-stable.git/arch/sparc/include/asm/setup.h, branch linux-3.12.y

sparc64: Fix register corruption in top-most kernel stack frame during boot.

2014-10-31T14:05:26+00:00

[ Upstream commit 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 
Tested-by: Meelis Roos 
Signed-off-by: David S. Miller

UAPI: (Scripted) Disintegrate arch/sparc/include/asm

2012-10-09T08:47:43+00:00

Signed-off-by: David Howells 
Acked-by: Arnd Bergmann 
Acked-by: Thomas Gleixner 
Acked-by: Michael Kerrisk 
Acked-by: Paul E. McKenney 
Acked-by: Dave Jones

sparc32: Remove unused empty_bad_page{,_table} declarations.

2012-05-20T04:45:08+00:00

Signed-off-by: David S. Miller

sparc32: Kill boot_cpu_id4

2012-05-20T04:40:50+00:00

It is written, but never actually read.

Signed-off-by: David S. Miller

Disintegrate asm/system.h for Sparc

2012-03-28T17:30:03+00:00

Disintegrate asm/system.h for Sparc.

Signed-off-by: David Howells 
cc: sparclinux@vger.kernel.org

sparc32: always define boot_cpu_id

2011-04-21T23:44:44+00:00

Define boot_cpu_id in single-processor kernels as well. This is
to support architectures which can boot on other than CPU0.

Sam Ravnborg has written the cleanup parts by extracting
boot_cpu_id from smp_32.c into setup_32.c and cleaned up
sun4d_irq.c.

boot_cpu_id was initialized before BSS was cleared in
sun4c_continue_boot, instead boot_cpu_id is set to 0xff to
avoid BSS. If boot_cpu_id is untouched (0xff) by bootup code
it will be overwritten to 0. boot_cpu_id4 is automatically
calculated in common code.

Signed-off-by: Daniel Hellstrom 
Signed-off-by: David S. Miller

sparc, sparc64: use arch/sparc/include

2008-07-27T21:00:59+00:00

The majority of this patch was created by the following script:

***
ASM=arch/sparc/include/asm
mkdir -p $ASM
git mv include/asm-sparc64/ftrace.h $ASM
git rm include/asm-sparc64/*
git mv include/asm-sparc/* $ASM
sed -ie 's/asm-sparc64/asm/g' $ASM/*
sed -ie 's/asm-sparc/asm/g' $ASM/*
***

The rest was an update of the top-level Makefile to use sparc
for header files when sparc64 is being build.
And a small fixlet to pick up the correct unistd.h from
sparc64 code.

Signed-off-by: Sam Ravnborg