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OpenCloudOS-Kernel/arch/sh/include/asm
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Bobby Bingham abafe5d9b0 sh: push extra copy of r0-r2 for syscall parameters 
When invoking syscall handlers on sh32, the saved userspace registers
are at the top of the stack.  This seems to have been intentional, as it
is an easy way to pass r0, r1, ...  to the handler as parameters 5, 6,
...

It causes problems, however, because the compiler is allowed to generate
code for a function which clobbers that function's own parameters.  For
example, gcc generates the following code for clone:

    <SyS_clone>:
        mov.l   8c020714 <SyS_clone+0xc>,r1  ! 8c020540 <do_fork>
        mov.l   r7,@r15
        mov     r6,r7
        jmp     @r1
        mov     #0,r6
        nop
        .word 0x0540
        .word 0x8c02

The `mov.l r7,@r15` clobbers the saved value of r0 passed from
userspace.  For most system calls, this might not be a problem, because
we'll be overwriting r0 with the return value anyway.  But in the case
of clone, copy_thread will need the original value of r0 if the
CLONE_SETTLS flag was specified.

The first patch in this series fixes this issue for system calls by
pushing to the stack and extra copy of r0-r2 before invoking the
handler.  We discard this copy before restoring the userspace registers,
so it is not a problem if they are clobbered.

Exception handlers also receive the userspace register values in a
similar manner, and may hit the same problem.  The second patch removes
the do_fpu_error handler, which looks susceptible to this problem and
which, as far as I can tell, has not been used in some time.  The third
patch addresses other exception handlers.

This patch (of 3):

The userspace registers are stored at the top of the stack when the
syscall handler is invoked, which allows r0-r2 to act as parameters 5-7.
Parameters passed on the stack may be clobbered by the syscall handler.
The solution is to push an extra copy of the registers which might be
used as syscall parameters to the stack, so that the authoritative set
of saved register values does not get clobbered.

A few system call handlers are also updated to get the userspace
registers using current_pt_regs() instead of from the stack.

Signed-off-by: Bobby Bingham <koorogi@koorogi.info>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 		2014-04-03 16:20:52 -07:00
..
Kbuild locking/mcs: Allow architecture specific asm files to be used for contended case 2014-02-09 21:18:52 +01:00
adc.h
…
addrspace.h sh: nommu: use 32-bit phys mode. 2010-11-04 12:32:24 +09:00
alignment.h sh: Split out the unaligned counters and user bits. 2010-01-12 16:12:25 +09:00
asm-offsets.h kbuild: move asm-offsets.h to include/generated 2009-12-12 13:08:14 +01:00
atomic-grb.h sh: consolidate atomic_cmpxchg()/atomic_add_unless() definitions. 2010-01-08 17:02:17 +09:00
atomic-irq.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
atomic-llsc.h sh: consolidate atomic_cmpxchg()/atomic_add_unless() definitions. 2010-01-08 17:02:17 +09:00
atomic.h sh: Fix up tracepoint build fallout from static key introduction. 2012-04-27 11:12:38 +09:30
barrier.h arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h 2014-01-12 10:37:15 +01:00
bitops-grb.h
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bitops-llsc.h sh: Relax inline assembly constraints 2009-01-29 11:57:09 +09:00
bitops-op32.h
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bitops.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
bl_bit.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
bl_bit_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
bl_bit_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
bug.h sh: Consolidate die definitions for trap handlers. 2012-06-14 14:18:51 +09:00
bugs.h sh: Idle loop chainsawing for SMP-based light sleep. 2009-10-16 17:20:58 +09:00
cache.h Merge branch 'for-35' of git://repo.or.cz/linux-kbuild 2010-06-01 08:55:52 -07:00
cache_insns.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
cache_insns_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
cache_insns_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
cacheflush.h sh: Assume new page cache pages have dirty dcache lines. 2010-12-01 15:39:51 +09:00
checksum.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
checksum_32.h
…
clkdev.h clk: Add common __clk_get(), __clk_put() implementations 2013-12-04 17:19:44 +01:00
clock.h sh: sh header sh_clk_ops rename 2012-03-12 22:19:10 +01:00
cmpxchg-grb.h sh: Fix up xchg/cmpxchg corruption with gUSA RB. 2011-06-08 15:22:39 +09:00
cmpxchg-irq.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
cmpxchg-llsc.h sh: Fix sh4a llsc-based cmpxchg() 2009-06-11 09:31:55 +03:00
cmpxchg.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
device.h sh: Defer to asm-generic/device.h. 2012-01-13 16:27:38 +09:00
dma-mapping.h sh: dma_debug: add debug_dma_mapping_error support 2012-11-28 15:29:00 +01:00
dma-register.h dmaengine: shdma: separate DMA headers. 2010-03-02 11:09:04 +09:00
dma.h sh: Kill off MAX_DMA_ADDRESS leftovers. 2012-05-19 18:50:09 +09:00
dmabrg.h
…
dwarf.h sh: Optimise FDE/CIE lookup by using red-black trees 2010-02-08 11:29:15 +09:00
elf.h sh: Fix FDPIC binary loader 2013-01-11 21:02:57 +09:00
entry-macros.S sh: Remove implicit sign extension from assembler immediates 2009-08-24 17:09:53 +09:00
fb.h
…
fixmap.h sh: use generic fixmap.h 2014-01-23 16:36:54 -08:00
flat.h flat: fix data sections alignment 2009-05-29 08:40:02 -07:00
fpu.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
freq.h
…
ftrace.h sh: Provide CALLER_ADDRx definitions even when ftrace is disabled. 2009-10-14 11:49:49 +09:00
futex-irq.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
futex.h futex: Sanitize futex ops argument types 2011-03-11 12:23:31 +01:00
gpio.h sh: Remove unused sh_pfc_register_info() function 2013-01-25 09:24:30 +09:00
hardirq.h sh: Count NMIs in irq_cpustat_t. 2009-10-14 16:42:28 +09:00
hd64461.h sh: mach-hp6xx: Fix up the hp6xx build for hd64461 changes. 2009-05-20 11:27:13 +09:00
heartbeat.h sh: Prevent heartbeat from scribbling over non-LED bits. 2009-08-18 21:16:29 +09:00
hugetlb.h mm/hugetlb: add more arch-defined huge_pte functions 2013-04-29 15:54:33 -07:00
hw_breakpoint.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
hw_irq.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
i2c-sh7760.h sh: edosk7760 evt2irq migration. 2012-05-18 14:52:31 +09:00
io.h /dev/mem: use phys_addr_t for physical addresses 2012-10-24 15:32:50 -07:00
io_generic.h sh: machvec IO death. 2010-11-01 09:49:04 -04:00
io_noioport.h SH: Convert out[bwl] macros to inline functions 2012-07-12 13:12:13 +09:00
io_trapped.h
…
irq.h sh: Kill off machvec IRQ hinting. 2012-05-21 17:54:01 +09:00
irqflags.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
kdebug.h sh64: Convert to unwinder API. 2012-05-24 15:03:46 +09:00
kexec.h sh: convert kexec crash kernel management to LMB. 2010-05-07 14:54:55 +09:00
kgdb.h sh: kgdb: Unset CACHE_FLUSH_IS_SAFE for SMP. 2012-04-11 10:48:24 +09:00
kmap_types.h kmap_types: make most arches use generic header file 2009-06-16 19:47:51 -07:00
kprobes.h sh: Add kprobe-based event tracer. 2010-06-14 15:16:53 +09:00
linkage.h
…
machvec.h sh: Kill off machvec IRQ hinting. 2012-05-21 17:54:01 +09:00
mc146818rtc.h
…
mmu.h sh: Fix up NUMA build for 29-bit. 2010-03-10 16:29:48 +09:00
mmu_context.h treewide: fix "distingush" typo 2013-10-14 15:38:33 +02:00
mmu_context_32.h sh: Mass ctrl_in/outX to __raw_read/writeX conversion. 2010-01-26 12:58:40 +09:00
mmu_context_64.h
…
mmzone.h Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
module.h Make most arch asm/module.h files use asm-generic/module.h 2012-09-28 14:31:03 +09:30
mutex-llsc.h arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not 2013-06-26 12:10:55 +02:00
mutex.h
…
page.h sh: Fix cached/uncaced address calculation in 29bit mode 2011-11-04 22:13:50 +09:00
pci.h PCI: collapse pcibios_resource_to_bus 2012-02-23 20:19:04 -07:00
perf_event.h irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
pgalloc.h sh: handle pgtable_page_ctor() fail 2013-11-15 09:32:18 +09:00
pgtable-2level.h sh: Rename split-level pgtable headers. 2010-01-13 19:18:39 +09:00
pgtable-3level.h sh: Rename split-level pgtable headers. 2010-01-13 19:18:39 +09:00
pgtable.h consolidate io_remap_pfn_range definitions 2013-06-29 12:46:35 +04:00
pgtable_32.h Fix common misspellings 2011-03-31 11:26:23 -03:00
pgtable_64.h sh64: Kill off unused fixed I/O mapping window. 2012-05-14 15:16:11 +09:00
posix_types.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
processor.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
processor_32.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
processor_64.h sh: move fpu_counter into ARCH specific thread_struct 2013-11-13 12:09:13 +09:00
ptrace.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
ptrace_32.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
ptrace_64.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
push-switch.h
…
reboot.h sh: machine_ops based reboot support. 2010-01-20 16:42:52 +09:00
romimage-macros.h sh: add romimage-macros.h 2009-09-11 13:19:16 +09:00
rtc.h sh: rtc-generic support. 2009-04-27 17:34:39 +09:00
rwsem.h rwsem: Move duplicate function prototypes to linux/rwsem.h 2011-01-27 12:30:39 +01:00
seccomp.h
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sections.h mtd/uclinux: Use generic __bss_stop instead of _ebss 2012-06-27 09:59:43 +02:00
segment.h
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setup.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
sfp-machine.h
…
sh7760fb.h
…
sh_bios.h sh: Kill off more unused sh_bios callbacks. 2010-01-12 15:26:11 +09:00
shmparam.h
…
siu.h sh: remove unused DMA device pointer from SIU platform data 2012-07-20 11:23:44 +05:30
smc37c93x.h
…
smp-ops.h sh: CPU hotplug support. 2010-04-26 19:08:55 +09:00
smp.h atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
sparsemem.h
…
spi.h
…
spinlock.h locking: Convert raw_rwlock functions to arch_rwlock 2009-12-14 23:55:32 +01:00
spinlock_types.h locking: Convert raw_rwlock to arch_rwlock 2009-12-14 23:55:32 +01:00
sram.h sh: Provide a generic SRAM pool for tiny memories. 2010-10-15 02:09:00 +09:00
stackprotector.h sh: initial stack protector support. 2012-04-19 15:45:57 +09:00
stacktrace.h sh: remove warning and warning_symbol from struct stacktrace_ops 2011-05-23 14:42:15 +09:00
string.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
string_32.h
…
string_64.h sh: Add SH-5 optimized memcpy()/memset()/strcpy()/strlen(). 2008-12-22 18:44:05 +09:00
suspend.h SH: cpuidle: check error code at init 2013-04-22 00:35:53 +02:00
switch_to.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
switch_to_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
switch_to_64.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
syscall.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
syscall_32.h sh: Add ftrace syscall tracing support 2009-07-06 20:16:33 +09:00
syscall_64.h sh: Fix up spurious syscall restarting. 2009-01-29 11:56:03 +09:00
syscalls.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
syscalls_32.h sh: push extra copy of r0-r2 for syscall parameters 2014-04-03 16:20:52 -07:00
syscalls_64.h sh: switch to generic fork/vfork/clone 2012-11-28 22:36:47 -05:00
thread_info.h preempt: Make PREEMPT_ACTIVE generic 2013-11-13 20:21:47 +01:00
timex.h sh: Only provide a PCLK definition for legacy CPG CPUs. 2009-12-29 11:09:30 +09:00
tlb.h Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
tlb_64.h
…
tlbflush.h sh: Provide a global TLB flush for U/I-TLB clear. 2010-07-02 15:44:09 +09:00
topology.h sched/numa: Rewrite the CONFIG_NUMA sched domain support 2012-05-09 15:00:55 +02:00
traps.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
traps_32.h Disintegrate asm/system.h for SH 2012-03-28 18:30:03 +01:00
traps_64.h sh64: Provide EXPEVT helper. 2012-05-14 13:04:08 +09:00
types.h UAPI: (Scripted) Disintegrate arch/sh/include/asm 2012-10-09 09:47:37 +01:00
uaccess.h UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers 2012-10-02 18:01:25 +01:00
uaccess_32.h sh: use the new generic strnlen_user() function 2012-06-13 10:28:37 +09:00
uaccess_64.h sh: use the new generic strnlen_user() function 2012-06-13 10:28:37 +09:00
unaligned-sh4a.h Fix common misspellings 2011-03-31 11:26:23 -03:00
unaligned.h sh: Convert to asm-generic/unaligned.h. 2009-06-14 23:24:43 +09:00
uncached.h sh: nommu: Support building without an uncached mapping. 2010-11-04 12:46:19 +09:00
unistd.h consolidate cond_syscall and SYSCALL_ALIAS declarations 2013-03-03 22:55:19 -05:00
unwinder.h sh: unwinder: Introduce UNWINDER_BUG() and UNWINDER_BUG_ON() 2009-08-21 13:02:44 +01:00
user.h
…
vga.h
…
vmlinux.lds.h sh64: fix up memory offset calculation. 2010-02-12 15:41:45 +09:00
watchdog.h sh: Mass ctrl_in/outX to __raw_read/writeX conversion. 2010-01-26 12:58:40 +09:00
word-at-a-time.h sh: use the new generic strnlen_user() function 2012-06-13 10:28:37 +09:00