ptrace has always returned only -EIO for all failures to access
registers. The user_regset calls are allowed to return a more
meaningful variety of errors. The REGSET_XFP calls use -ENODEV
for !cpu_has_fxsr hardware. Make ptrace return the traditional
-EIO instead of the error code from the user_regset call.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch disables suspend/resume on machines with AMD IOMMU enabled. Real
suspend/resume support for AMD IOMMU is currently being worked on. Until this
is ready it will be disabled to avoid data corruption when the IOMMU is not
properly re-enabled at resume. The patch is based on a similar patch for the
GART driver written by Pavel Machek.
The overall driver merged into tip/master is tested with parallel disk and
network loads and showed no problems in a test running for 3 days.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ptrace GET/SET FPXREGS broken
x86: fix cpu hotplug crash
x86: section/warning fixes
x86: shift bits the right way in native_read_tscp
When I update kernel 2.6.25 from 2.6.24, gdb does not work.
On 2.6.25, ptrace(PTRACE_GETFPXREGS, ...) returns ENODEV.
But 2.6.24 kernel's ptrace() returns EIO.
It is issue of compatibility.
I attached test program as pt.c and patch for fix it.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sys/ptrace.h>
#include <sys/types.h>
struct user_fxsr_struct {
unsigned short cwd;
unsigned short swd;
unsigned short twd;
unsigned short fop;
long fip;
long fcs;
long foo;
long fos;
long mxcsr;
long reserved;
long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */
long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */
long padding[56];
};
int main(void)
{
pid_t pid;
pid = fork();
switch(pid){
case -1:/* error */
break;
case 0:/* child */
child();
break;
default:
parent(pid);
break;
}
return 0;
}
int child(void)
{
ptrace(PTRACE_TRACEME);
kill(getpid(), SIGSTOP);
sleep(10);
return 0;
}
int parent(pid_t pid)
{
int ret;
struct user_fxsr_struct fpxregs;
ret = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpxregs);
if(ret < 0){
printf("%d: %s.\n", errno, strerror(errno));
}
kill(pid, SIGCONT);
wait(pid);
return 0;
}
/* in the kerel, at kernel/i387.c get_fpxregs() */
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Vegard Nossum reported crashes during cpu hotplug tests:
http://marc.info/?l=linux-kernel&m=121413950227884&w=4
In function _cpu_up, the panic happens when calling
__raw_notifier_call_chain at the second time. Kernel doesn't panic when
calling it at the first time. If just say because of nr_cpu_ids, that's
not right.
By checking the source code, I found that function do_boot_cpu is the culprit.
Consider below call chain:
_cpu_up=>__cpu_up=>smp_ops.cpu_up=>native_cpu_up=>do_boot_cpu.
So do_boot_cpu is called in the end. In do_boot_cpu, if
boot_error==true, cpu_clear(cpu, cpu_possible_map) is executed. So later
on, when _cpu_up calls __raw_notifier_call_chain at the second time to
report CPU_UP_CANCELED, because this cpu is already cleared from
cpu_possible_map, get_cpu_sysdev returns NULL.
Many resources are related to cpu_possible_map, so it's better not to
change it.
Below patch against 2.6.26-rc7 fixes it by removing the bit clearing in
cpu_possible_map.
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
small speedup.
Paravirt replacements were added to the i386 module loader by commit
139ec7c416. This adds the same code to
the x86_64 module loader.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
From the code:
"B stepping K8s sometimes report an truncated RIP for IRET exceptions
returning to compat mode. Check for these here too."
The code then proceeds to truncate the upper 32 bits of %rbp. This means
that when do_page_fault() is finally called, its prologue,
do_page_fault:
push %rbp
movl %rsp, %rbp
will put the truncated base pointer on the stack. This means that the
stack tracer will not be able to follow the base-pointer changes and
will see all subsequent stack frames as unreliable.
This patch changes the code to use a different register (%rcx) for the
checking and leaves %rbp untouched.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
arch/x86/kernel/process.c: In function 'cpu_idle_wait':
arch/x86/kernel/process.c:64: error: too many arguments to function 'smp_call_function'
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
arch/x86/kernel/amd_iommu.c: In function ‘amd_iommu_init_dma_ops':
arch/x86/kernel/amd_iommu.c:940: error: lvalue required as left operand of assignment
arch/x86/kernel/amd_iommu.c:941: error: lvalue required as left operand of assignment
due to !CONFIG_GART_IOMMU.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This converts x86, x86-64, and xen to use the new helpers for
smp_call_function() and friends, and adds support for
smp_call_function_single().
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds paravirt-ops hooks in pv_mmu_ops for ptep_modify_prot_start and
ptep_modify_prot_commit. This allows the hypervisor-specific backends to
implement these in some more efficient way.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
