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| author | Michael Ellerman <mpe@ellerman.id.au> | 2015-04-30 15:13:14 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-04-30 15:24:58 +1000 |
| commit | 68fc378ce332cc4efd7f314d3e6e15e83f53ebf2 (patch) | |
| tree | 5a539c138cad206146296eaf0c6e0ea81655d4ee /arch | |
| parent | d33047fd7e7d93662622888681861ba84d43c506 (diff) | |
| download | lwn-68fc378ce332cc4efd7f314d3e6e15e83f53ebf2.tar.gz lwn-68fc378ce332cc4efd7f314d3e6e15e83f53ebf2.zip | |
Revert "powerpc/tm: Abort syscalls in active transactions"
This reverts commit feba40362b11341bee6d8ed58d54b896abbd9f84.
Although the principle of this change is good, the implementation has a
few issues.
Firstly we can sometimes fail to abort a syscall because r12 may have
been clobbered by C code if we went down the virtual CPU accounting
path, or if syscall tracing was enabled.
Secondly we have decided that it is safer to abort the syscall even
earlier in the syscall entry path, so that we avoid the syscall tracing
path when we are transactional.
So that we have time to thoroughly test those changes we have decided to
revert this for this merge window and will merge the fixed version in
the next window.
NB. Rather than reverting the selftest we just drop tm-syscall from
TEST_PROGS so that it's not run by default.
Fixes: feba40362b11 ("powerpc/tm: Abort syscalls in active transactions")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/uapi/asm/tm.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 19 |
2 files changed, 1 insertions, 20 deletions
diff --git a/arch/powerpc/include/uapi/asm/tm.h b/arch/powerpc/include/uapi/asm/tm.h index 5047659815a5..5d836b7c1176 100644 --- a/arch/powerpc/include/uapi/asm/tm.h +++ b/arch/powerpc/include/uapi/asm/tm.h @@ -11,7 +11,7 @@ #define TM_CAUSE_RESCHED 0xde #define TM_CAUSE_TLBI 0xdc #define TM_CAUSE_FAC_UNAV 0xda -#define TM_CAUSE_SYSCALL 0xd8 +#define TM_CAUSE_SYSCALL 0xd8 /* future use */ #define TM_CAUSE_MISC 0xd6 /* future use */ #define TM_CAUSE_SIGNAL 0xd4 #define TM_CAUSE_ALIGNMENT 0xd2 diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 8ca9434c40e6..afbc20019c2e 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -34,7 +34,6 @@ #include <asm/ftrace.h> #include <asm/hw_irq.h> #include <asm/context_tracking.h> -#include <asm/tm.h> /* * System calls. @@ -146,24 +145,6 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) andi. r11,r10,_TIF_SYSCALL_DOTRACE bne syscall_dotrace .Lsyscall_dotrace_cont: -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM -BEGIN_FTR_SECTION - b 1f -END_FTR_SECTION_IFCLR(CPU_FTR_TM) - extrdi. r11, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */ - beq+ 1f - - /* Doom the transaction and don't perform the syscall: */ - mfmsr r11 - li r12, 1 - rldimi r11, r12, MSR_TM_LG, 63-MSR_TM_LG - mtmsrd r11, 0 - li r11, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT) - TABORT(R11) - - b .Lsyscall_exit -1: -#endif cmpldi 0,r0,NR_syscalls bge- syscall_enosys |