From a215c8fbde8600d133f122691d0f8c30de6dda02 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Jun 2015 14:52:13 +0200 Subject: s390/oprofile: fix compile error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix these errors when compiling with CONFIG_OPROFILE=y and CONFIG_PERF_EVENTS=n: arch/s390/oprofile/init.c: In function ‘oprofile_hwsampler_start’: arch/s390/oprofile/init.c:93:2: error: implicit declaration of function 'perf_reserve_sampling' [-Werror=implicit-function-declaration] retval = perf_reserve_sampling(); ^ arch/s390/oprofile/init.c:99:3: error: implicit declaration of function 'perf_release_sampling' [-Werror=implicit-function-declaration] perf_release_sampling(); ^ Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/perf_event.h | 8 ++++++++ arch/s390/oprofile/init.c | 1 + 2 files changed, 9 insertions(+) (limited to 'arch') diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h index 4cb19fe76dd9..f897ec73dc8c 100644 --- a/arch/s390/include/asm/perf_event.h +++ b/arch/s390/include/asm/perf_event.h @@ -87,7 +87,15 @@ struct sf_raw_sample { } __packed; /* Perf hardware reserve and release functions */ +#ifdef CONFIG_PERF_EVENTS int perf_reserve_sampling(void); void perf_release_sampling(void); +#else /* CONFIG_PERF_EVENTS */ +static inline int perf_reserve_sampling(void) +{ + return 0; +} +static inline void perf_release_sampling(void) {} +#endif /* CONFIG_PERF_EVENTS */ #endif /* _ASM_S390_PERF_EVENT_H */ diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index bc927a09a172..9cfa2ffaa9d6 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "../../../drivers/oprofile/oprof.h" -- cgit v1.2.3 From f9c87a6f46d508eae0d9ae640be98d50f237f827 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 6 Jul 2015 17:58:19 +0200 Subject: s390/sclp: clear upper register halves in _sclp_print_early If the kernel is compiled with gcc 5.1 and the XZ compression option the decompress_kernel function calls _sclp_print_early in 64-bit mode while the content of the upper register half of %r6 is non-zero. This causes a specification exception on the servc instruction in _sclp_servc. The _sclp_print_early function saves and restores the upper registers halves but it fails to clear them for the 31-bit code of the mini sclp driver. Cc: Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/sclp.S | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S index 43c3169ea49c..ada0c07fe1a8 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -270,6 +270,8 @@ ENTRY(_sclp_print_early) jno .Lesa2 ahi %r15,-80 stmh %r6,%r15,96(%r15) # store upper register halves + basr %r13,0 + lmh %r0,%r15,.Lzeroes-.(%r13) # clear upper register halves .Lesa2: lr %r10,%r2 # save string pointer lhi %r2,0 @@ -291,6 +293,8 @@ ENTRY(_sclp_print_early) .Lesa3: lm %r6,%r15,120(%r15) # restore registers br %r14 +.Lzeroes: + .fill 64,4,0 .LwritedataS4: .long 0x00760005 # SCLP command for write data -- cgit v1.2.3 From e47994dd44bcb4a77b4152bd0eada585934703c0 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 6 Jul 2015 15:02:37 +0200 Subject: s390/process: fix sfpc inline assembly The sfpc inline assembly within execve_tail() may incorrectly set bits 28-31 of the sfpc instruction to a value which is not zero. These bits however are currently unused and therefore should be zero so we won't get surprised if these bits will be used in the future. Therefore remove the second operand from the inline assembly. Cc: Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index dc5edc29b73a..8f587d871b9f 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -163,7 +163,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, asmlinkage void execve_tail(void) { current->thread.fp_regs.fpc = 0; - asm volatile("sfpc %0,%0" : : "d" (0)); + asm volatile("sfpc %0" : : "d" (0)); } /* -- cgit v1.2.3 From cad49cfc44a5160e3fa09b18e4e7f7cacd13f27d Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 7 Jul 2015 08:40:49 +0200 Subject: s390/nmi: fix vector register corruption If a machine check happens, the machine has the vector facility installed and the extended save area exists, the cpu will save vector register contents into the extended save area. This is regardless of control register 0 contents, which enables and disables the vector facility during runtime. On each machine check we should validate the vector registers. The current code however tries to validate the registers only if the running task is using vector registers in user space. However even the current code is broken and causes vector register corruption on machine checks, if user space uses them: the prefix area contains a pointer (absolute address) to the machine check extended save area. In order to save some space the save area was put into an unused area of the second prefix page. When validating vector register contents the code uses the absolute address of the extended save area, which is wrong. Due to prefixing the vector instructions will then access contents using absolute addresses instead of real addresses, where the machine stored the contents. If the above would work there is still the problem that register validition would only happen if user space uses vector registers. If kernel space uses them also, this may also lead to vector register content corruption: if the kernel makes use of vector instructions, but the current running user space context does not, the machine check handler will validate floating point registers instead of vector registers. Given the fact that writing to a floating point register may change the upper halve of the corresponding vector register, we also experience vector register corruption in this case. Fix all of these issues, and always validate vector registers on each machine check, if the machine has the vector facility installed and the extended save area is defined. Cc: # 4.1+ Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/ctl_reg.h | 5 +++- arch/s390/kernel/nmi.c | 51 ++++++++++++++++++++++++----------------- 2 files changed, 34 insertions(+), 22 deletions(-) (limited to 'arch') diff --git a/arch/s390/include/asm/ctl_reg.h b/arch/s390/include/asm/ctl_reg.h index cfad7fca01d6..d7697ab802f6 100644 --- a/arch/s390/include/asm/ctl_reg.h +++ b/arch/s390/include/asm/ctl_reg.h @@ -57,7 +57,10 @@ union ctlreg0 { unsigned long lap : 1; /* Low-address-protection control */ unsigned long : 4; unsigned long edat : 1; /* Enhanced-DAT-enablement control */ - unsigned long : 23; + unsigned long : 4; + unsigned long afp : 1; /* AFP-register control */ + unsigned long vx : 1; /* Vector enablement control */ + unsigned long : 17; }; }; diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 505c17c0ae1a..56b550893593 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -21,6 +21,7 @@ #include #include #include +#include struct mcck_struct { int kill_task; @@ -129,26 +130,30 @@ static int notrace s390_revalidate_registers(struct mci *mci) } else asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area)); - asm volatile( - " ld 0,0(%0)\n" - " ld 1,8(%0)\n" - " ld 2,16(%0)\n" - " ld 3,24(%0)\n" - " ld 4,32(%0)\n" - " ld 5,40(%0)\n" - " ld 6,48(%0)\n" - " ld 7,56(%0)\n" - " ld 8,64(%0)\n" - " ld 9,72(%0)\n" - " ld 10,80(%0)\n" - " ld 11,88(%0)\n" - " ld 12,96(%0)\n" - " ld 13,104(%0)\n" - " ld 14,112(%0)\n" - " ld 15,120(%0)\n" - : : "a" (fpt_save_area)); - /* Revalidate vector registers */ - if (MACHINE_HAS_VX && current->thread.vxrs) { + if (!MACHINE_HAS_VX) { + /* Revalidate floating point registers */ + asm volatile( + " ld 0,0(%0)\n" + " ld 1,8(%0)\n" + " ld 2,16(%0)\n" + " ld 3,24(%0)\n" + " ld 4,32(%0)\n" + " ld 5,40(%0)\n" + " ld 6,48(%0)\n" + " ld 7,56(%0)\n" + " ld 8,64(%0)\n" + " ld 9,72(%0)\n" + " ld 10,80(%0)\n" + " ld 11,88(%0)\n" + " ld 12,96(%0)\n" + " ld 13,104(%0)\n" + " ld 14,112(%0)\n" + " ld 15,120(%0)\n" + : : "a" (fpt_save_area)); + } else { + /* Revalidate vector registers */ + union ctlreg0 cr0; + if (!mci->vr) { /* * Vector registers can't be restored and therefore @@ -156,8 +161,12 @@ static int notrace s390_revalidate_registers(struct mci *mci) */ kill_task = 1; } + cr0.val = S390_lowcore.cregs_save_area[0]; + cr0.afp = cr0.vx = 1; + __ctl_load(cr0.val, 0, 0); restore_vx_regs((__vector128 *) - S390_lowcore.vector_save_area_addr); + &S390_lowcore.vector_save_area); + __ctl_load(S390_lowcore.cregs_save_area[0], 0, 0); } /* Revalidate access registers */ asm volatile( -- cgit v1.2.3