The user_regset_view table for the 32-bit regsets on the 64-bit build had
the wrong sizes for the FP regsets. This bug had no user-visible effect
(just on kernel modules using the user_regset interfaces and the like).
But the fix is trivial and risk-free.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that there are no more special cases in sys32_ptrace, we
can convert to using the generic compat_sys_ptrace entry point.
The sys32_ptrace function gets simpler and becomes compat_arch_ptrace.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This removes the special-case handling for PTRACE_GETSIGINFO
and PTRACE_SETSIGINFO from x86_64's sys32_ptrace. The generic
compat_ptrace_request code handles these.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/ptrace.c:548: warning: 'ptrace_bts_get_size' defined but not used
arch/x86/kernel/ptrace.c:558: warning: 'ptrace_bts_read_record' defined but not used
arch/x86/kernel/ptrace.c:607: warning: 'ptrace_bts_clear' defined but not used
arch/x86/kernel/ptrace.c:617: warning: 'ptrace_bts_drain' defined but not used
arch/x86/kernel/ptrace.c:720: warning: 'ptrace_bts_config' defined but not used
arch/x86/kernel/ptrace.c:788: warning: 'ptrace_bts_status' defined but not used
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The code to restart syscalls after signals depends on checking for a
negative orig_ax, and for particular negative -ERESTART* values in ax.
These fields are 64 bits and for a 32-bit task they get zero-extended.
The syscall restart behavior is lost, a regression from a native 32-bit
kernel and from 64-bit tasks' behavior.
This patch fixes the problem by doing sign-extension where it matters.
For orig_ax, the only time the value should be -1 but winds up as
0x0ffffffff is via a 32-bit ptrace call. So the patch changes ptrace to
sign-extend the 32-bit orig_eax value when it's stored; it doesn't
change the checks on orig_ax, though it uses the new current_syscall()
inline to better document the subtle importance of the used of
signedness there.
The ax value is stored a lot of ways and it seems hard to get them all
sign-extended at their origins. So for that, we use the
current_syscall_ret() to sign-extend it only for 32-bit tasks at the
time of the -ERESTART* comparisons.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This makes 64-bit ptrace calls setting the 64-bit orig_ax field for a
32-bit task sign-extend the low 32 bits up to 64. This matches what a
64-bit debugger expects when tracing a 32-bit task.
This follows on my "x86_64 ia32 syscall restart fix". This didn't
matter until that was fixed.
The debugger ignores or zeros the high half of every register slot it
sets (including the orig_rax pseudo-register) uniformly. It expects
that the setting of the low 32 bits always has the same meaning as a
32-bit debugger setting those same 32 bits with native 32-bit
facilities.
This never arose before because the syscall restart check never
matched any -ERESTART* values due to lack of sign extension. Before
that fix, even 32-bit ptrace setting orig_eax to -1 failed to trigger
the restart check anyway. So this was never noticed as a regression
of 64-bit debuggers vs 32-bit debuggers on the same 64-bit kernel.
Signed-off-by: Roland McGrath <roland@redhat.com>
[ Changed to just do the sign-extension unconditionally on x86-64,
since orig_ax is always just a small integer and doesn't need
the full 64-bit range ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
revert the BTS ptrace extension for now.
based on general objections from Roland McGrath:
http://lkml.org/lkml/2008/2/21/323
we'll let the BTS functionality cook some more and re-enable
it in v2.6.26. We'll leave the dead code around to help the
development of this code.
(X86_BTS is not defined at the moment)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In my revamp of the x86 ptrace code for setting register values,
I accidentally omitted a check that was there in the old code.
Allowing %cs to be 0 causes a bad crash in recovery from iret failure.
This patch fixes that regression against 2.6.24, and adds a comment
that should help prevent this subtlety from being overlooked again.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Return the size of bts_struct in the PTRACE_BTS_STATUS command.
Change types to u32.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pass the buffer size for (most) ptrace commands that pass user-allocated buffers and check that size before accessing the buffer. Unfortunately, PTRACE_BTS_GET already uses all 4 parameters.
Commands that access user buffers return the number of bytes or records read or written.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Check the rlimit of the tracing task for total and locked memory when allocating the BTS buffer.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This removes duplicated code by calling the generic ptrace_request and
compat_ptrace_request functions for the things they already handle.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This makes ELF core dumps of 32-bit processes include a new
note type NT_386_TLS (0x200) giving the contents of the TLS
slots in struct user_desc format. This lets post mortem
examination figure out what the segment registers mean like
the debugger does with get_thread_area on a live process.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This cleans up the PTRACE_*REGS* request code so each one is just a
simple call to copy_regset_to_user or copy_regset_from_user. The
ptrace layouts already match the user_regset formats (core dump formats).
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This defines task_user_regset_view and the tables
describing the x86 user_regset layouts for 32 and 64.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds accessor functions in the user_regset style for
the general registers (struct user_regs_struct).
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This revamps the i387 code to be shared across 32-bit, 64-bit,
and 32-on-64. It does so by consolidating the code in one place
based on the user_regset accessor interfaces. This switches
32-bit to using the i387_64.h header and 64-bit to using the
i387.c that was previously i387_32.c, but that's what took the
least cleanup in each file. Here i387.h is stubbed to always
include i387_64.h rather than renaming the file, to keep this
diff smaller and easier to read.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Here's the new ptrace BTS API that supports two different overflow handling mechanisms (wrap-around and buffer-full-signal) to support two different use cases (debugging and profiling).
It further combines buffer allocation and configuration.
Opens:
- memory rlimit
- overflow signal
What would be the right signal to use?
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Resend using different mail client
Changes to the last version:
- split implementation into two layers: ds/bts and ptrace
- renamed TIF's
- save/restore ds save area msr in __switch_to_xtra()
- make block-stepping only look at BTF bit
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This moves the sys32_ptrace code into arch/x86/kernel/ptrace.c,
verbatim except for a few hard-coded sizes replaced with sizeof.
Here this code can use the shared local functions in this file.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
