From 1739f09e33d8f66bf48ddbc3eca615574da6c4f6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 13 Nov 2013 15:20:04 -0500 Subject: ftrace/x86: Load ftrace_ops in parameter not the variable holding it Function tracing callbacks expect to have the ftrace_ops that registered it passed to them, not the address of the variable that holds the ftrace_ops that registered it. Use a mov instead of a lea to store the ftrace_ops into the parameter of the function tracing callback. Signed-off-by: Steven Rostedt Reviewed-by: Masami Hiramatsu Link: http://lkml.kernel.org/r/20131113152004.459787f9@gandalf.local.home Signed-off-by: H. Peter Anvin Cc: # v3.8+ --- arch/x86/kernel/entry_32.S | 4 ++-- arch/x86/kernel/entry_64.S | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 51e2988c5728..a2a4f4697889 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1082,7 +1082,7 @@ ENTRY(ftrace_caller) pushl $0 /* Pass NULL as regs pointer */ movl 4*4(%esp), %eax movl 0x4(%ebp), %edx - leal function_trace_op, %ecx + movl function_trace_op, %ecx subl $MCOUNT_INSN_SIZE, %eax .globl ftrace_call @@ -1140,7 +1140,7 @@ ENTRY(ftrace_regs_caller) movl 12*4(%esp), %eax /* Load ip (1st parameter) */ subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */ - leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ + movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ pushl %esp /* Save pt_regs as 4th parameter */ GLOBAL(ftrace_regs_call) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index e21b0785a85b..1e96c3628bf2 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -88,7 +88,7 @@ END(function_hook) MCOUNT_SAVE_FRAME \skip /* Load the ftrace_ops into the 3rd parameter */ - leaq function_trace_op, %rdx + movq function_trace_op(%rip), %rdx /* Load ip into the first parameter */ movq RIP(%rsp), %rdi -- cgit v1.2.3 From 26bef1318adc1b3a530ecc807ef99346db2aa8b0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 11 Jan 2014 19:15:52 -0800 Subject: x86, fpu, amd: Clear exceptions in AMD FXSAVE workaround Before we do an EMMS in the AMD FXSAVE information leak workaround we need to clear any pending exceptions, otherwise we trap with a floating-point exception inside this code. Reported-by: halfdog Tested-by: Borislav Petkov Link: http://lkml.kernel.org/r/CA%2B55aFxQnY_PCG_n4=0w-VG=YLXL-yr7oMxyy0WU2gCBAf3ydg@mail.gmail.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/fpu-internal.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index c49a613c6452..cea1c76d49bf 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -293,12 +293,13 @@ static inline int restore_fpu_checking(struct task_struct *tsk) /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is pending. Clear the x87 state here by setting it to fixed values. "m" is a random variable that should be in L1 */ - alternative_input( - ASM_NOP8 ASM_NOP2, - "emms\n\t" /* clear stack tags */ - "fildl %P[addr]", /* set F?P to defined value */ - X86_FEATURE_FXSAVE_LEAK, - [addr] "m" (tsk->thread.fpu.has_fpu)); + if (unlikely(static_cpu_has(X86_FEATURE_FXSAVE_LEAK))) { + asm volatile( + "fnclex\n\t" + "emms\n\t" + "fildl %P[addr]" /* set F?P to defined value */ + : : [addr] "m" (tsk->thread.fpu.has_fpu)); + } return fpu_restore_checking(&tsk->thread.fpu); } -- cgit v1.2.3 From 0c3351d451ae2fa438d5d1ed719fc43354fbffbb Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 2 Jan 2014 15:11:13 -0800 Subject: seqlock: Use raw_ prefix instead of _no_lockdep MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Linus disliked the _no_lockdep() naming, so instead use the more-consistent raw_* prefix to the non-lockdep enabled seqcount methods. This also adds raw_ methods for the write operations as well, which will be utilized in a following patch. Acked-by: Linus Torvalds Reviewed-by: Stephen Boyd Signed-off-by: John Stultz Signed-off-by: Peter Zijlstra Cc: Krzysztof Hałasa Cc: Uwe Kleine-König Cc: Willy Tarreau Link: http://lkml.kernel.org/r/1388704274-5278-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- arch/x86/vdso/vclock_gettime.c | 8 ++++---- include/linux/seqlock.h | 27 +++++++++++++++++++-------- 2 files changed, 23 insertions(+), 12 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 2ada505067cc..eb5d7a56f8d4 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -178,7 +178,7 @@ notrace static int __always_inline do_realtime(struct timespec *ts) ts->tv_nsec = 0; do { - seq = read_seqcount_begin_no_lockdep(>od->seq); + seq = raw_read_seqcount_begin(>od->seq); mode = gtod->clock.vclock_mode; ts->tv_sec = gtod->wall_time_sec; ns = gtod->wall_time_snsec; @@ -198,7 +198,7 @@ notrace static int do_monotonic(struct timespec *ts) ts->tv_nsec = 0; do { - seq = read_seqcount_begin_no_lockdep(>od->seq); + seq = raw_read_seqcount_begin(>od->seq); mode = gtod->clock.vclock_mode; ts->tv_sec = gtod->monotonic_time_sec; ns = gtod->monotonic_time_snsec; @@ -214,7 +214,7 @@ notrace static int do_realtime_coarse(struct timespec *ts) { unsigned long seq; do { - seq = read_seqcount_begin_no_lockdep(>od->seq); + seq = raw_read_seqcount_begin(>od->seq); ts->tv_sec = gtod->wall_time_coarse.tv_sec; ts->tv_nsec = gtod->wall_time_coarse.tv_nsec; } while (unlikely(read_seqcount_retry(>od->seq, seq))); @@ -225,7 +225,7 @@ notrace static int do_monotonic_coarse(struct timespec *ts) { unsigned long seq; do { - seq = read_seqcount_begin_no_lockdep(>od->seq); + seq = raw_read_seqcount_begin(>od->seq); ts->tv_sec = gtod->monotonic_time_coarse.tv_sec; ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec; } while (unlikely(read_seqcount_retry(>od->seq, seq))); diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index cf87a24c0f92..535f158977b9 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -117,15 +117,15 @@ repeat: } /** - * read_seqcount_begin_no_lockdep - start seq-read critical section w/o lockdep + * raw_read_seqcount_begin - start seq-read critical section w/o lockdep * @s: pointer to seqcount_t * Returns: count to be passed to read_seqcount_retry * - * read_seqcount_begin_no_lockdep opens a read critical section of the given + * raw_read_seqcount_begin opens a read critical section of the given * seqcount, but without any lockdep checking. Validity of the critical * section is tested by checking read_seqcount_retry function. */ -static inline unsigned read_seqcount_begin_no_lockdep(const seqcount_t *s) +static inline unsigned raw_read_seqcount_begin(const seqcount_t *s) { unsigned ret = __read_seqcount_begin(s); smp_rmb(); @@ -144,7 +144,7 @@ static inline unsigned read_seqcount_begin_no_lockdep(const seqcount_t *s) static inline unsigned read_seqcount_begin(const seqcount_t *s) { seqcount_lockdep_reader_access(s); - return read_seqcount_begin_no_lockdep(s); + return raw_read_seqcount_begin(s); } /** @@ -206,14 +206,26 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) } + +static inline void raw_write_seqcount_begin(seqcount_t *s) +{ + s->sequence++; + smp_wmb(); +} + +static inline void raw_write_seqcount_end(seqcount_t *s) +{ + smp_wmb(); + s->sequence++; +} + /* * Sequence counter only version assumes that callers are using their * own mutexing. */ static inline void write_seqcount_begin_nested(seqcount_t *s, int subclass) { - s->sequence++; - smp_wmb(); + raw_write_seqcount_begin(s); seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_); } @@ -225,8 +237,7 @@ static inline void write_seqcount_begin(seqcount_t *s) static inline void write_seqcount_end(seqcount_t *s) { seqcount_release(&s->dep_map, 1, _RET_IP_); - smp_wmb(); - s->sequence++; + raw_write_seqcount_end(s); } /** -- cgit v1.2.3 From 0dce7cd67fd9055c4a2ff278f8af1431e646d346 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Wed, 15 Jan 2014 13:39:59 +0100 Subject: kvm: x86: fix apic_base enable check Commit e66d2ae7c67bd moved the assignment vcpu->arch.apic_base = value above a condition with (vcpu->arch.apic_base ^ value), causing that check to always fail. Use old_value, vcpu->arch.apic_base's old value, in the condition instead. Signed-off-by: Andrew Jones Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 1673940cf9c3..775702f649ca 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1355,7 +1355,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) vcpu->arch.apic_base = value; /* update jump label if enable bit changes */ - if ((vcpu->arch.apic_base ^ value) & MSR_IA32_APICBASE_ENABLE) { + if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) { if (value & MSR_IA32_APICBASE_ENABLE) static_key_slow_dec_deferred(&apic_hw_disabled); else -- cgit v1.2.3 From aee636c4809fa54848ff07a899b326eb1f9987a2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 15 Jan 2014 06:50:07 -0800 Subject: bpf: do not use reciprocal divide At first Jakub Zawadzki noticed that some divisions by reciprocal_divide were not correct. (off by one in some cases) http://www.wireshark.org/~darkjames/reciprocal-buggy.c He could also show this with BPF: http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c The reciprocal divide in linux kernel is not generic enough, lets remove its use in BPF, as it is not worth the pain with current cpus. Signed-off-by: Eric Dumazet Reported-by: Jakub Zawadzki Cc: Mircea Gherzan Cc: Daniel Borkmann Cc: Hannes Frederic Sowa Cc: Matt Evans Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: David S. Miller Signed-off-by: David S. Miller --- arch/arm/net/bpf_jit_32.c | 6 +++--- arch/powerpc/net/bpf_jit_comp.c | 7 ++++--- arch/s390/net/bpf_jit_comp.c | 17 ++++++++++++----- arch/sparc/net/bpf_jit_comp.c | 17 ++++++++++++++--- arch/x86/net/bpf_jit_comp.c | 14 ++++++++++---- net/core/filter.c | 30 ++---------------------------- 6 files changed, 45 insertions(+), 46 deletions(-) (limited to 'arch/x86') diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 9ed155ad0f97..271b5e971568 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -641,10 +641,10 @@ load_ind: emit(ARM_MUL(r_A, r_A, r_X), ctx); break; case BPF_S_ALU_DIV_K: - /* current k == reciprocal_value(userspace k) */ + if (k == 1) + break; emit_mov_i(r_scratch, k, ctx); - /* A = top 32 bits of the product */ - emit(ARM_UMULL(r_scratch, r_A, r_A, r_scratch), ctx); + emit_udiv(r_A, r_A, r_scratch, ctx); break; case BPF_S_ALU_DIV_X: update_on_xread(ctx); diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index ac3c2a10dafd..555034f8505e 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -223,10 +223,11 @@ static int bpf_jit_build_body(struct sk_filter *fp, u32 *image, } PPC_DIVWU(r_A, r_A, r_X); break; - case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K); */ + case BPF_S_ALU_DIV_K: /* A /= K */ + if (K == 1) + break; PPC_LI32(r_scratch1, K); - /* Top 32 bits of 64bit result -> A */ - PPC_MULHWU(r_A, r_A, r_scratch1); + PPC_DIVWU(r_A, r_A, r_scratch1); break; case BPF_S_ALU_AND_X: ctx->seen |= SEEN_XREG; diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 16871da37371..fc0fa77728e1 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -371,11 +371,13 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter, /* dr %r4,%r12 */ EMIT2(0x1d4c); break; - case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K) */ - /* m %r4,(%r13) */ - EMIT4_DISP(0x5c40d000, EMIT_CONST(K)); - /* lr %r5,%r4 */ - EMIT2(0x1854); + case BPF_S_ALU_DIV_K: /* A /= K */ + if (K == 1) + break; + /* lhi %r4,0 */ + EMIT4(0xa7480000); + /* d %r4,(%r13) */ + EMIT4_DISP(0x5d40d000, EMIT_CONST(K)); break; case BPF_S_ALU_MOD_X: /* A %= X */ jit->seen |= SEEN_XREG | SEEN_RET0; @@ -391,6 +393,11 @@ static int bpf_jit_insn(struct bpf_jit *jit, struct sock_filter *filter, EMIT2(0x1854); break; case BPF_S_ALU_MOD_K: /* A %= K */ + if (K == 1) { + /* lhi %r5,0 */ + EMIT4(0xa7580000); + break; + } /* lhi %r4,0 */ EMIT4(0xa7480000); /* d %r4,(%r13) */ diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c index 218b6b23c378..01fe9946d388 100644 --- a/arch/sparc/net/bpf_jit_comp.c +++ b/arch/sparc/net/bpf_jit_comp.c @@ -497,9 +497,20 @@ void bpf_jit_compile(struct sk_filter *fp) case BPF_S_ALU_MUL_K: /* A *= K */ emit_alu_K(MUL, K); break; - case BPF_S_ALU_DIV_K: /* A /= K */ - emit_alu_K(MUL, K); - emit_read_y(r_A); + case BPF_S_ALU_DIV_K: /* A /= K with K != 0*/ + if (K == 1) + break; + emit_write_y(G0); +#ifdef CONFIG_SPARC32 + /* The Sparc v8 architecture requires + * three instructions between a %y + * register write and the first use. + */ + emit_nop(); + emit_nop(); + emit_nop(); +#endif + emit_alu_K(DIV, K); break; case BPF_S_ALU_DIV_X: /* A /= X; */ emit_cmpi(r_X, 0); diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 26328e800869..4ed75dd81d05 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -359,15 +359,21 @@ void bpf_jit_compile(struct sk_filter *fp) EMIT2(0x89, 0xd0); /* mov %edx,%eax */ break; case BPF_S_ALU_MOD_K: /* A %= K; */ + if (K == 1) { + CLEAR_A(); + break; + } EMIT2(0x31, 0xd2); /* xor %edx,%edx */ EMIT1(0xb9);EMIT(K, 4); /* mov imm32,%ecx */ EMIT2(0xf7, 0xf1); /* div %ecx */ EMIT2(0x89, 0xd0); /* mov %edx,%eax */ break; - case BPF_S_ALU_DIV_K: /* A = reciprocal_divide(A, K); */ - EMIT3(0x48, 0x69, 0xc0); /* imul imm32,%rax,%rax */ - EMIT(K, 4); - EMIT4(0x48, 0xc1, 0xe8, 0x20); /* shr $0x20,%rax */ + case BPF_S_ALU_DIV_K: /* A /= K */ + if (K == 1) + break; + EMIT2(0x31, 0xd2); /* xor %edx,%edx */ + EMIT1(0xb9);EMIT(K, 4); /* mov imm32,%ecx */ + EMIT2(0xf7, 0xf1); /* div %ecx */ break; case BPF_S_ALU_AND_X: seen |= SEEN_XREG; diff --git a/net/core/filter.c b/net/core/filter.c index 01b780856db2..ad30d626a5bd 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -36,7 +36,6 @@ #include #include #include -#include #include #include #include @@ -166,7 +165,7 @@ unsigned int sk_run_filter(const struct sk_buff *skb, A /= X; continue; case BPF_S_ALU_DIV_K: - A = reciprocal_divide(A, K); + A /= K; continue; case BPF_S_ALU_MOD_X: if (X == 0) @@ -553,11 +552,6 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) /* Some instructions need special checks */ switch (code) { case BPF_S_ALU_DIV_K: - /* check for division by zero */ - if (ftest->k == 0) - return -EINVAL; - ftest->k = reciprocal_value(ftest->k); - break; case BPF_S_ALU_MOD_K: /* check for division by zero */ if (ftest->k == 0) @@ -853,27 +847,7 @@ void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) to->code = decodes[code]; to->jt = filt->jt; to->jf = filt->jf; - - if (code == BPF_S_ALU_DIV_K) { - /* - * When loaded this rule user gave us X, which was - * translated into R = r(X). Now we calculate the - * RR = r(R) and report it back. If next time this - * value is loaded and RRR = r(RR) is calculated - * then the R == RRR will be true. - * - * One exception. X == 1 translates into R == 0 and - * we can't calculate RR out of it with r(). - */ - - if (filt->k == 0) - to->k = 1; - else - to->k = reciprocal_value(filt->k); - - BUG_ON(reciprocal_value(to->k) != filt->k); - } else - to->k = filt->k; + to->k = filt->k; } int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) -- cgit v1.2.3