diff options
| author | Cyril Bur <cyrilbur@gmail.com> | 2016-08-10 15:44:46 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-08-10 16:34:20 +1000 |
| commit | c7a318ba868c61fc9be710a4970172d8c2eeb8b9 (patch) | |
| tree | b3967ee9f5b893af024f0376d120bb30d6297dd1 /arch/powerpc/kernel/ptrace.c | |
| parent | 1bc8b816cb8058c31f61fe78442f10a43209e582 (diff) | |
powerpc/ptrace: Fix coredump since ptrace TM changes
Commit 8d460f6156cd ("powerpc/process: Add the function
flush_tmregs_to_thread") added flush_tmregs_to_thread() and included
the assumption that it would only be called for a task which is not
current.
Although this is correct for ptrace, when generating a core dump, some
of the routines which call flush_tmregs_to_thread() are called. This
leads to a WARNing such as:
Not expecting ptrace on self: TM regs may be incorrect
------------[ cut here ]------------
WARNING: CPU: 123 PID: 7727 at arch/powerpc/kernel/process.c:1088 flush_tmregs_to_thread+0x78/0x80
CPU: 123 PID: 7727 Comm: libvirtd Not tainted 4.8.0-rc1-gcc6x-g61e8a0d #1
task: c000000fe631b600 task.stack: c000000fe63b0000
NIP: c00000000001a1a8 LR: c00000000001a1a4 CTR: c000000000717780
REGS: c000000fe63b3420 TRAP: 0700 Not tainted (4.8.0-rc1-gcc6x-g61e8a0d)
MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28004222 XER: 20000000
...
NIP [c00000000001a1a8] flush_tmregs_to_thread+0x78/0x80
LR [c00000000001a1a4] flush_tmregs_to_thread+0x74/0x80
Call Trace:
flush_tmregs_to_thread+0x74/0x80 (unreliable)
vsr_get+0x64/0x1a0
elf_core_dump+0x604/0x1430
do_coredump+0x5fc/0x1200
get_signal+0x398/0x740
do_signal+0x54/0x2b0
do_notify_resume+0x98/0xb0
ret_from_except_lite+0x70/0x74
So fix flush_tmregs_to_thread() to detect the case where it is called on
current, and a transaction is active, and in that case flush the TM regs
to the thread_struct.
This patch also moves flush_tmregs_to_thread() into ptrace.c as it is
only called from that file.
Fixes: 8d460f6156cd ("powerpc/process: Add the function flush_tmregs_to_thread")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Flesh out change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/ptrace.c')
| -rw-r--r-- | arch/powerpc/kernel/ptrace.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 4f3c5756cc09..bf91658a8a40 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -38,6 +38,7 @@ #include <asm/page.h> #include <asm/pgtable.h> #include <asm/switch_to.h> +#include <asm/tm.h> #define CREATE_TRACE_POINTS #include <trace/events/syscalls.h> @@ -118,6 +119,24 @@ static const struct pt_regs_offset regoffset_table[] = { REG_OFFSET_END, }; +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +static void flush_tmregs_to_thread(struct task_struct *tsk) +{ + /* + * If task is not current, it will have been flushed already to + * it's thread_struct during __switch_to(). + * + * A reclaim flushes ALL the state. + */ + + if (tsk == current && MSR_TM_SUSPENDED(mfmsr())) + tm_reclaim_current(TM_CAUSE_SIGNAL); + +} +#else +static inline void flush_tmregs_to_thread(struct task_struct *tsk) { } +#endif + /** * regs_query_register_offset() - query register offset from its name * @name: the name of a register |