From 87dc669ba25777b67796d7262c569429e58b1ed4 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 8 Apr 2011 17:29:36 +0200 Subject: x86, hw_breakpoints: Fix racy access to ptrace breakpoints While the tracer accesses ptrace breakpoints, the child task may concurrently exit due to a SIGKILL and thus release its breakpoints at the same time. We can then dereference some freed pointers. To fix this, hold a reference on the child breakpoints before manipulating them. Reported-by: Oleg Nesterov Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Will Deacon Cc: Prasad Cc: Paul Mundt Cc: v2.6.33.. Link: http://lkml.kernel.org/r/1302284067-7860-3-git-send-email-fweisbec@gmail.com --- arch/x86/kernel/ptrace.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 45892dc4b72a..f65e5b521dbd 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -608,6 +608,9 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data) unsigned len, type; struct perf_event *bp; + if (ptrace_get_breakpoints(tsk) < 0) + return -ESRCH; + data &= ~DR_CONTROL_RESERVED; old_dr7 = ptrace_get_dr7(thread->ptrace_bps); restore: @@ -655,6 +658,9 @@ restore: } goto restore; } + + ptrace_put_breakpoints(tsk); + return ((orig_ret < 0) ? orig_ret : rc); } @@ -668,10 +674,17 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n) if (n < HBP_NUM) { struct perf_event *bp; + + if (ptrace_get_breakpoints(tsk) < 0) + return -ESRCH; + bp = thread->ptrace_bps[n]; if (!bp) - return 0; - val = bp->hw.info.address; + val = 0; + else + val = bp->hw.info.address; + + ptrace_put_breakpoints(tsk); } else if (n == 6) { val = thread->debugreg6; } else if (n == 7) { @@ -686,6 +699,10 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, struct perf_event *bp; struct thread_struct *t = &tsk->thread; struct perf_event_attr attr; + int err = 0; + + if (ptrace_get_breakpoints(tsk) < 0) + return -ESRCH; if (!t->ptrace_bps[nr]) { ptrace_breakpoint_init(&attr); @@ -709,24 +726,23 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, * writing for the user. And anyway this is the previous * behaviour. */ - if (IS_ERR(bp)) - return PTR_ERR(bp); + if (IS_ERR(bp)) { + err = PTR_ERR(bp); + goto put; + } t->ptrace_bps[nr] = bp; } else { - int err; - bp = t->ptrace_bps[nr]; attr = bp->attr; attr.bp_addr = addr; err = modify_user_hw_breakpoint(bp, &attr); - if (err) - return err; } - - return 0; +put: + ptrace_put_breakpoints(tsk); + return err; } /* -- cgit From e20a2d205c05cef6b5783df339a7d54adeb50962 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Fri, 29 Apr 2011 17:47:43 -0400 Subject: x86, AMD: Fix APIC timer erratum 400 affecting K8 Rev.A-E processors Older AMD K8 processors (Revisions A-E) are affected by erratum 400 (APIC timer interrupts don't occur in C states greater than C1). This, for example, means that X86_FEATURE_ARAT flag should not be set for these parts. This addresses regression introduced by commit b87cf80af3ba4b4c008b4face3c68d604e1715c6 ("x86, AMD: Set ARAT feature on AMD processors") where the system may become unresponsive until external interrupt (such as keyboard input) occurs. This results, for example, in time not being reported correctly, lack of progress on the system and other lockups. Reported-by: Joerg-Volker Peetz Tested-by: Joerg-Volker Peetz Acked-by: Borislav Petkov Signed-off-by: Boris Ostrovsky Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1304113663-6586-1-git-send-email-ostr@amd64.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 3532d3bf8105..bb9eb29a52dd 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -698,7 +698,7 @@ cpu_dev_register(amd_cpu_dev); */ const int amd_erratum_400[] = - AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf), + AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0x0f, 0x4, 0x2, 0xff, 0xf), AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf)); EXPORT_SYMBOL_GPL(amd_erratum_400); -- cgit From 7806a49ab625ebeb1709e5e87299b64932b807a7 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 2 May 2011 14:33:24 -0700 Subject: x86, reboot: Fix relocations in reboot_32.S The use of base for %ebx in this file is arbitrary, *except* that we also use it to compute the real-mode segment. Therefore, make it so that r_base really is the true address to which %ebx points. This resolves kernel bugzilla 33302. Reported-and-tested-by: Alexey Zaytsev Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/n/tip-08os5wi3yq1no0y4i5m4z7he@git.kernel.org --- arch/x86/kernel/reboot_32.S | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/reboot_32.S b/arch/x86/kernel/reboot_32.S index 29092b38d816..1d5c46df0d78 100644 --- a/arch/x86/kernel/reboot_32.S +++ b/arch/x86/kernel/reboot_32.S @@ -21,26 +21,26 @@ r_base = . /* Get our own relocated address */ call 1f 1: popl %ebx - subl $1b, %ebx + subl $(1b - r_base), %ebx /* Compute the equivalent real-mode segment */ movl %ebx, %ecx shrl $4, %ecx /* Patch post-real-mode segment jump */ - movw dispatch_table(%ebx,%eax,2),%ax - movw %ax, 101f(%ebx) - movw %cx, 102f(%ebx) + movw (dispatch_table - r_base)(%ebx,%eax,2),%ax + movw %ax, (101f - r_base)(%ebx) + movw %cx, (102f - r_base)(%ebx) /* Set up the IDT for real mode. */ - lidtl machine_real_restart_idt(%ebx) + lidtl (machine_real_restart_idt - r_base)(%ebx) /* * Set up a GDT from which we can load segment descriptors for real * mode. The GDT is not used in real mode; it is just needed here to * prepare the descriptors. */ - lgdtl machine_real_restart_gdt(%ebx) + lgdtl (machine_real_restart_gdt - r_base)(%ebx) /* * Load the data segment registers with 16-bit compatible values -- cgit From 63b6a6758eede2f9283c3594265b6e32e75d7456 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sat, 23 Apr 2011 00:57:42 +0200 Subject: perf events, x86: Fix Intel Nehalem and Westmere last level cache event definitions The Intel Nehalem offcore bits implemented in: e994d7d23a0b: perf: Fix LLC-* events on Intel Nehalem/Westmere ... are wrong: they implemented _ACCESS as _HIT and counted OTHER_CORE_HIT* as MISS even though its clearly documented as an L3 hit ... Fix them and the Westmere definitions as well. Cc: Andi Kleen Cc: Lin Ming Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1299119690-13991-3-git-send-email-ming.m.lin@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 87 ++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 35 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index e61539b07d2c..447a28de6f09 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -184,26 +184,23 @@ static __initconst const u64 snb_hw_cache_event_ids }, }, [ C(LL ) ] = { - /* - * TBD: Need Off-core Response Performance Monitoring support - */ [ C(OP_READ) ] = { - /* OFFCORE_RESPONSE_0.ANY_DATA.LOCAL_CACHE */ + /* OFFCORE_RESPONSE.ANY_DATA.LOCAL_CACHE */ [ C(RESULT_ACCESS) ] = 0x01b7, - /* OFFCORE_RESPONSE_1.ANY_DATA.ANY_LLC_MISS */ - [ C(RESULT_MISS) ] = 0x01bb, + /* OFFCORE_RESPONSE.ANY_DATA.ANY_LLC_MISS */ + [ C(RESULT_MISS) ] = 0x01b7, }, [ C(OP_WRITE) ] = { - /* OFFCORE_RESPONSE_0.ANY_RFO.LOCAL_CACHE */ + /* OFFCORE_RESPONSE.ANY_RFO.LOCAL_CACHE */ [ C(RESULT_ACCESS) ] = 0x01b7, - /* OFFCORE_RESPONSE_1.ANY_RFO.ANY_LLC_MISS */ - [ C(RESULT_MISS) ] = 0x01bb, + /* OFFCORE_RESPONSE.ANY_RFO.ANY_LLC_MISS */ + [ C(RESULT_MISS) ] = 0x01b7, }, [ C(OP_PREFETCH) ] = { - /* OFFCORE_RESPONSE_0.PREFETCH.LOCAL_CACHE */ + /* OFFCORE_RESPONSE.PREFETCH.LOCAL_CACHE */ [ C(RESULT_ACCESS) ] = 0x01b7, - /* OFFCORE_RESPONSE_1.PREFETCH.ANY_LLC_MISS */ - [ C(RESULT_MISS) ] = 0x01bb, + /* OFFCORE_RESPONSE.PREFETCH.ANY_LLC_MISS */ + [ C(RESULT_MISS) ] = 0x01b7, }, }, [ C(DTLB) ] = { @@ -285,26 +282,26 @@ static __initconst const u64 westmere_hw_cache_event_ids }, [ C(LL ) ] = { [ C(OP_READ) ] = { - /* OFFCORE_RESPONSE_0.ANY_DATA.LOCAL_CACHE */ + /* OFFCORE_RESPONSE.ANY_DATA.LOCAL_CACHE */ [ C(RESULT_ACCESS) ] = 0x01b7, - /* OFFCORE_RESPONSE_1.ANY_DATA.ANY_LLC_MISS */ - [ C(RESULT_MISS) ] = 0x01bb, + /* OFFCORE_RESPONSE.ANY_DATA.ANY_LLC_MISS */ + [ C(RESULT_MISS) ] = 0x01b7, }, /* * Use RFO, not WRITEBACK, because a write miss would typically occur * on RFO. */ [ C(OP_WRITE) ] = { - /* OFFCORE_RESPONSE_1.ANY_RFO.LOCAL_CACHE */ - [ C(RESULT_ACCESS) ] = 0x01bb, - /* OFFCORE_RESPONSE_0.ANY_RFO.ANY_LLC_MISS */ + /* OFFCORE_RESPONSE.ANY_RFO.LOCAL_CACHE */ + [ C(RESULT_ACCESS) ] = 0x01b7, + /* OFFCORE_RESPONSE.ANY_RFO.ANY_LLC_MISS */ [ C(RESULT_MISS) ] = 0x01b7, }, [ C(OP_PREFETCH) ] = { - /* OFFCORE_RESPONSE_0.PREFETCH.LOCAL_CACHE */ + /* OFFCORE_RESPONSE.PREFETCH.LOCAL_CACHE */ [ C(RESULT_ACCESS) ] = 0x01b7, - /* OFFCORE_RESPONSE_1.PREFETCH.ANY_LLC_MISS */ - [ C(RESULT_MISS) ] = 0x01bb, + /* OFFCORE_RESPONSE.PREFETCH.ANY_LLC_MISS */ + [ C(RESULT_MISS) ] = 0x01b7, }, }, [ C(DTLB) ] = { @@ -352,16 +349,36 @@ static __initconst const u64 westmere_hw_cache_event_ids }; /* - * OFFCORE_RESPONSE MSR bits (subset), See IA32 SDM Vol 3 30.6.1.3 + * Nehalem/Westmere MSR_OFFCORE_RESPONSE bits; + * See IA32 SDM Vol 3B 30.6.1.3 */ -#define DMND_DATA_RD (1 << 0) -#define DMND_RFO (1 << 1) -#define DMND_WB (1 << 3) -#define PF_DATA_RD (1 << 4) -#define PF_DATA_RFO (1 << 5) -#define RESP_UNCORE_HIT (1 << 8) -#define RESP_MISS (0xf600) /* non uncore hit */ +#define NHM_DMND_DATA_RD (1 << 0) +#define NHM_DMND_RFO (1 << 1) +#define NHM_DMND_IFETCH (1 << 2) +#define NHM_DMND_WB (1 << 3) +#define NHM_PF_DATA_RD (1 << 4) +#define NHM_PF_DATA_RFO (1 << 5) +#define NHM_PF_IFETCH (1 << 6) +#define NHM_OFFCORE_OTHER (1 << 7) +#define NHM_UNCORE_HIT (1 << 8) +#define NHM_OTHER_CORE_HIT_SNP (1 << 9) +#define NHM_OTHER_CORE_HITM (1 << 10) + /* reserved */ +#define NHM_REMOTE_CACHE_FWD (1 << 12) +#define NHM_REMOTE_DRAM (1 << 13) +#define NHM_LOCAL_DRAM (1 << 14) +#define NHM_NON_DRAM (1 << 15) + +#define NHM_ALL_DRAM (NHM_REMOTE_DRAM|NHM_LOCAL_DRAM) + +#define NHM_DMND_READ (NHM_DMND_DATA_RD) +#define NHM_DMND_WRITE (NHM_DMND_RFO|NHM_DMND_WB) +#define NHM_DMND_PREFETCH (NHM_PF_DATA_RD|NHM_PF_DATA_RFO) + +#define NHM_L3_HIT (NHM_UNCORE_HIT|NHM_OTHER_CORE_HIT_SNP|NHM_OTHER_CORE_HITM) +#define NHM_L3_MISS (NHM_NON_DRAM|NHM_ALL_DRAM|NHM_REMOTE_CACHE_FWD) +#define NHM_L3_ACCESS (NHM_L3_HIT|NHM_L3_MISS) static __initconst const u64 nehalem_hw_cache_extra_regs [PERF_COUNT_HW_CACHE_MAX] @@ -370,16 +387,16 @@ static __initconst const u64 nehalem_hw_cache_extra_regs { [ C(LL ) ] = { [ C(OP_READ) ] = { - [ C(RESULT_ACCESS) ] = DMND_DATA_RD|RESP_UNCORE_HIT, - [ C(RESULT_MISS) ] = DMND_DATA_RD|RESP_MISS, + [ C(RESULT_ACCESS) ] = NHM_DMND_READ|NHM_L3_ACCESS, + [ C(RESULT_MISS) ] = NHM_DMND_READ|NHM_L3_MISS, }, [ C(OP_WRITE) ] = { - [ C(RESULT_ACCESS) ] = DMND_RFO|DMND_WB|RESP_UNCORE_HIT, - [ C(RESULT_MISS) ] = DMND_RFO|DMND_WB|RESP_MISS, + [ C(RESULT_ACCESS) ] = NHM_DMND_WRITE|NHM_L3_ACCESS, + [ C(RESULT_MISS) ] = NHM_DMND_WRITE|NHM_L3_MISS, }, [ C(OP_PREFETCH) ] = { - [ C(RESULT_ACCESS) ] = PF_DATA_RD|PF_DATA_RFO|RESP_UNCORE_HIT, - [ C(RESULT_MISS) ] = PF_DATA_RD|PF_DATA_RFO|RESP_MISS, + [ C(RESULT_ACCESS) ] = NHM_DMND_PREFETCH|NHM_L3_ACCESS, + [ C(RESULT_MISS) ] = NHM_DMND_PREFETCH|NHM_L3_MISS, }, } }; -- cgit