BMC/Intel-BMC/linux.git/arch/x86/mm/kmemcheck, branch dev

x86: Replace __get_cpu_var uses

2014-08-26T17:45:49+00:00

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Thomas Gleixner Cc: x86@kernel.org Acked-by: H. Peter Anvin Acked-by: Ingo Molnar Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo

arch/x86/mm/kmemcheck/kmemcheck.c: use kstrtoint() instead of sscanf()

2014-04-08T23:48:52+00:00

Kmemcheck should use the preferred interface for parsing command line arguments, kstrto*(), rather than sscanf() itself. Use it appropriately. Signed-off-by: David Rientjes Cc: Vegard Nossum Acked-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bug.h: add include of it to various implicit C users

2012-02-29T22:15:08+00:00

With bug.h currently living right in linux/kernel.h there are files that use BUG_ON and friends but are not including the header explicitly. Fix them up so we can remove the presence in kernel.h file. Signed-off-by: Paul Gortmaker

x86: Swap save_stack_trace_regs parameters

2011-06-15T02:48:51+00:00

Swap the 1st and 2nd parameters of save_stack_trace_regs() as same as the parameters of save_stack_trace_tsk(). Signed-off-by: Masami Hiramatsu Cc: yrl.pp-manager.tt@hitachi.com Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20110608070921.17777.31103.stgit@fedora15 Signed-off-by: Steven Rostedt

x86: Eliminate bp argument from the stack tracing routines

2010-11-18T13:37:34+00:00

The various stack tracing routines take a 'bp' argument in which the caller is supposed to provide the base pointer to use, or 0 if doesn't have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not defined, this means all callers in principle should either always pass 0, or be conditional on CONFIG_FRAME_POINTER. However, there are only really three use cases for stack tracing: (a) Trace the current task, including IRQ stack if any (b) Trace the current task, but skip IRQ stack (c) Trace some other task In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just be 0. If it _is_ defined, then - in case (a) bp should be gotten directly from the CPU's register, so the caller should pass NULL for regs, - in case (b) the caller should should pass the IRQ registers to dump_trace(), - in case (c) bp should be gotten from the top of the task's stack, so the caller should pass NULL for regs. Hence, the bp argument is not necessary because the combination of task and regs is sufficient to determine an appropriate value for bp. This patch introduces a new inline function stack_frame(task, regs) that computes the desired bp. This function is then called from the two versions of dump_stack(). Signed-off-by: Soren Sandmann Acked-by: Steven Rostedt Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Peter Zijlstra Cc: Arjan van de Ven , Cc: Frederic Weisbecker , Cc: Arnaldo Carvalho de Melo , LKML-Reference: > Signed-off-by: Frederic Weisbecker

Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-10-21T20:47:29+00:00

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-32, percpu: Correct the ordering of the percpu readmostly section x86, mm: Enable ARCH_DMA_ADDR_T_64BIT with X86_64 || HIGHMEM64G x86: Spread tlb flush vector between nodes percpu: Introduce a read-mostly percpu API x86, mm: Fix incorrect data type in vmalloc_sync_all() x86, mm: Hold mm->page_table_lock while doing vmalloc_sync x86, mm: Fix bogus whitespace in sync_global_pgds() x86-32: Fix sparse warning for the __PHYSICAL_MASK calculation x86, mm: Add RESERVE_BRK_ARRAY() helper mm, x86: Saving vmcore with non-lazy freeing of vmas x86, kdump: Change copy_oldmem_page() to use cached addressing x86, mm: fix uninitialized addr in kernel_physical_mapping_init() x86, kmemcheck: Remove double test x86, mm: Make spurious_fault check explicitly check the PRESENT bit x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes x86, mm: Separate x86_64 vmalloc_sync_all() into separate functions x86, mm: Avoid unnecessary TLB flush

x86: Barf when vmalloc and kmemcheck faults happen in NMI

2010-10-14T18:43:36+00:00

In x86, faults exit by executing the iret instruction, which then reenables NMIs if we faulted in NMI context. Then if a fault happens in NMI, another NMI can nest after the fault exits. But we don't yet support nested NMIs because we have only one NMI stack. To prevent from that, check that vmalloc and kmemcheck faults don't happen in this context. Most of the other kernel faults in NMIs can be more easily spotted by finding explicit copy_from,to_user() calls on review. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Mathieu Desnoyers Cc: Peter Zijlstra

x86, kmemcheck: Remove double test

2010-08-30T07:19:28+00:00

The opcodes 0x2e and 0x3e are tested for in the first Group 2 line as well. The sematic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @expression@ expression E; @@ ( * E || ... || E | * E && ... && E ) // Signed-off-by: Julia Lawall Reviewed-by: Pekka Enberg Cc: Vegard Nossum LKML-Reference: <1283010066-20935-5-git-send-email-julia@diku.dk> Signed-off-by: Ingo Molnar

kmemcheck: Test the full object in kmemcheck_is_obj_initialized()

2010-02-17T19:39:08+00:00

This is a fix for bug #14845 (bugzilla.kernel.org). The update_checksum() function in mm/kmemleak.c calls kmemcheck_is_obj_initialised() before scanning an object. When KMEMCHECK_PARTIAL_OK is enabled, this function returns true. However, the crc32_le() reads smaller intervals (32-bit) for which kmemleak_is_obj_initialised() may be false leading to a kmemcheck warning. Note that kmemcheck_is_obj_initialized() is currently only used by kmemleak before scanning a memory location. Signed-off-by: Catalin Marinas Cc: Andrew Morton Cc: Christian Casteyde Cc: Vegard Nossum Signed-off-by: Pekka Enberg

x86, kmemcheck: Use KERN_WARNING for error reporting

2009-12-28T09:28:35+00:00

As suggested by Vegard Nossum, use KERN_WARNING for error reporting to make sure kmemcheck reports end up in syslog. Suggested-by: Vegard Nossum Signed-off-by: Pekka Enberg Cc: Andrew Morton LKML-Reference: <1261990935.4641.7.camel@penberg-laptop> Signed-off-by: Ingo Molnar