From 86069782d62e731b4835a0cf8eb7d1d0e17cf306 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:56 +0200 Subject: x86: add a list for custom page fault handlers. Provides kernel modules a way to register custom page fault handlers. On every page fault this will call a list of registered functions. The functions may handle the fault and force do_page_fault() to return immediately. This functionality is similar to the now removed page fault notifiers. Custom page fault handlers are used by debugging and reverse engineering tools. Mmiotrace is one such tool and a patch to add it into the tree will follow. The custom page fault handlers are called earlier in do_page_fault() than the page fault notifiers were. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/fault.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index fd7e1798c75..343f5c1aacc 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -49,6 +49,60 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) +#ifdef CONFIG_PAGE_FAULT_HANDLERS +static HLIST_HEAD(pf_handlers); /* protected by RCU */ +static DEFINE_SPINLOCK(pf_handlers_writer); + +void register_page_fault_handler(struct pf_handler *new_pfh) +{ + unsigned long flags; + spin_lock_irqsave(&pf_handlers_writer, flags); + hlist_add_head_rcu(&new_pfh->hlist, &pf_handlers); + spin_unlock_irqrestore(&pf_handlers_writer, flags); +} +EXPORT_SYMBOL_GPL(register_page_fault_handler); + +/** + * unregister_page_fault_handler: + * The caller must ensure @old_pfh is not in use anymore before freeing it. + * This function does not guarantee it. The list of handlers is protected by + * RCU, so you can do this by e.g. calling synchronize_rcu(). + */ +void unregister_page_fault_handler(struct pf_handler *old_pfh) +{ + unsigned long flags; + spin_lock_irqsave(&pf_handlers_writer, flags); + hlist_del_rcu(&old_pfh->hlist); + spin_unlock_irqrestore(&pf_handlers_writer, flags); +} +EXPORT_SYMBOL_GPL(unregister_page_fault_handler); +#endif + +/* returns non-zero if do_page_fault() should return */ +static int handle_custom_pf(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ +#ifdef CONFIG_PAGE_FAULT_HANDLERS + int ret = 0; + struct pf_handler *cur; + struct hlist_node *ncur; + + if (hlist_empty(&pf_handlers)) + return 0; + + rcu_read_lock(); + hlist_for_each_entry_rcu(cur, ncur, &pf_handlers, hlist) { + ret = cur->handler(regs, error_code, address); + if (ret) + break; + } + rcu_read_unlock(); + return ret; +#else + return 0; +#endif +} + static inline int notify_page_fault(struct pt_regs *regs) { #ifdef CONFIG_KPROBES @@ -601,6 +655,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; + if (handle_custom_pf(regs, error_code, address)) + return; /* * We fault-in kernel-space virtual memory on-demand. The -- cgit v1.2.3 From 10c43d2eb50c9a5ad60388b9d3c41c31150049e6 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86: explicit call to mmiotrace in do_page_fault() The custom page fault handler list is replaced with a single function pointer. All related functions and variables are renamed for mmiotrace. Signed-off-by: Pekka Paalanen Cc: Christoph Hellwig Cc: Arjan van de Ven Cc: pq@iki.fi Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/fault.c | 66 +++++++++++++++++++++++++++-------------------------- 1 file changed, 34 insertions(+), 32 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 343f5c1aacc..e9a086a1a9f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -49,53 +49,55 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) -#ifdef CONFIG_PAGE_FAULT_HANDLERS -static HLIST_HEAD(pf_handlers); /* protected by RCU */ -static DEFINE_SPINLOCK(pf_handlers_writer); +#ifdef CONFIG_MMIOTRACE_HOOKS +static pf_handler_func mmiotrace_pf_handler; /* protected by RCU */ +static DEFINE_SPINLOCK(mmiotrace_handler_lock); -void register_page_fault_handler(struct pf_handler *new_pfh) +int mmiotrace_register_pf(pf_handler_func new_pfh) { + int ret = 0; unsigned long flags; - spin_lock_irqsave(&pf_handlers_writer, flags); - hlist_add_head_rcu(&new_pfh->hlist, &pf_handlers); - spin_unlock_irqrestore(&pf_handlers_writer, flags); + spin_lock_irqsave(&mmiotrace_handler_lock, flags); + if (mmiotrace_pf_handler) + ret = -EBUSY; + else + mmiotrace_pf_handler = new_pfh; + spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); + return ret; } -EXPORT_SYMBOL_GPL(register_page_fault_handler); +EXPORT_SYMBOL_GPL(mmiotrace_register_pf); /** - * unregister_page_fault_handler: + * mmiotrace_unregister_pf: * The caller must ensure @old_pfh is not in use anymore before freeing it. - * This function does not guarantee it. The list of handlers is protected by - * RCU, so you can do this by e.g. calling synchronize_rcu(). + * This function does not guarantee it. The handler function pointer is + * protected by RCU, so you can do this by e.g. calling synchronize_rcu(). */ -void unregister_page_fault_handler(struct pf_handler *old_pfh) +int mmiotrace_unregister_pf(pf_handler_func old_pfh) { + int ret = 0; unsigned long flags; - spin_lock_irqsave(&pf_handlers_writer, flags); - hlist_del_rcu(&old_pfh->hlist); - spin_unlock_irqrestore(&pf_handlers_writer, flags); + spin_lock_irqsave(&mmiotrace_handler_lock, flags); + if (mmiotrace_pf_handler != old_pfh) + ret = -EPERM; + else + mmiotrace_pf_handler = NULL; + spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); + return ret; } -EXPORT_SYMBOL_GPL(unregister_page_fault_handler); -#endif +EXPORT_SYMBOL_GPL(mmiotrace_unregister_pf); +#endif /* CONFIG_MMIOTRACE_HOOKS */ /* returns non-zero if do_page_fault() should return */ -static int handle_custom_pf(struct pt_regs *regs, unsigned long error_code, - unsigned long address) +static inline int call_mmiotrace(struct pt_regs *regs, + unsigned long error_code, + unsigned long address) { -#ifdef CONFIG_PAGE_FAULT_HANDLERS +#ifdef CONFIG_MMIOTRACE_HOOKS int ret = 0; - struct pf_handler *cur; - struct hlist_node *ncur; - - if (hlist_empty(&pf_handlers)) - return 0; - rcu_read_lock(); - hlist_for_each_entry_rcu(cur, ncur, &pf_handlers, hlist) { - ret = cur->handler(regs, error_code, address); - if (ret) - break; - } + if (mmiotrace_pf_handler) + ret = mmiotrace_pf_handler(regs, error_code, address); rcu_read_unlock(); return ret; #else @@ -655,7 +657,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; - if (handle_custom_pf(regs, error_code, address)) + if (call_mmiotrace(regs, error_code, address)) return; /* -- cgit v1.2.3 From 0fd0e3da4557c479b820b9a4a7afa25b4637ddf2 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86: mmiotrace full patch, preview 1 kmmio.c handles the list of mmio probes with callbacks, list of traced pages, and attaching into the page fault handler and die notifier. It arms, traps and disarms the given pages, this is the core of mmiotrace. mmio-mod.c is a user interface, hooking into ioremap functions and registering the mmio probes. It also decodes the required information from trapped mmio accesses via the pre and post callbacks in each probe. Currently, hooking into ioremap functions works by redefining the symbols of the target (binary) kernel module, so that it calls the traced versions of the functions. The most notable changes done since the last discussion are: - kmmio.c is a built-in, not part of the module - direct call from fault.c to kmmio.c, removing all dynamic hooks - prepare for unregistering probes at any time - make kmmio re-initializable and accessible to more than one user - rewrite kmmio locking to remove all spinlocks from page fault path Can I abuse call_rcu() like I do in kmmio.c:unregister_kmmio_probe() or is there a better way? The function called via call_rcu() itself calls call_rcu() again, will this work or break? There I need a second grace period for RCU after the first grace period for page faults. Mmiotrace itself (mmio-mod.c) is still a module, I am going to attack that next. At some point I will start looking into how to make mmiotrace a tracer component of ftrace (thanks for the hint, Ingo). Ftrace should make the user space part of mmiotracing as simple as 'cat /debug/trace/mmio > dump.txt'. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/fault.c | 59 +++++++---------------------------------------------- 1 file changed, 7 insertions(+), 52 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e9a086a1a9f..8c828a68d3b 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -49,60 +50,14 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) -#ifdef CONFIG_MMIOTRACE_HOOKS -static pf_handler_func mmiotrace_pf_handler; /* protected by RCU */ -static DEFINE_SPINLOCK(mmiotrace_handler_lock); - -int mmiotrace_register_pf(pf_handler_func new_pfh) -{ - int ret = 0; - unsigned long flags; - spin_lock_irqsave(&mmiotrace_handler_lock, flags); - if (mmiotrace_pf_handler) - ret = -EBUSY; - else - mmiotrace_pf_handler = new_pfh; - spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); - return ret; -} -EXPORT_SYMBOL_GPL(mmiotrace_register_pf); - -/** - * mmiotrace_unregister_pf: - * The caller must ensure @old_pfh is not in use anymore before freeing it. - * This function does not guarantee it. The handler function pointer is - * protected by RCU, so you can do this by e.g. calling synchronize_rcu(). - */ -int mmiotrace_unregister_pf(pf_handler_func old_pfh) -{ - int ret = 0; - unsigned long flags; - spin_lock_irqsave(&mmiotrace_handler_lock, flags); - if (mmiotrace_pf_handler != old_pfh) - ret = -EPERM; - else - mmiotrace_pf_handler = NULL; - spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); - return ret; -} -EXPORT_SYMBOL_GPL(mmiotrace_unregister_pf); -#endif /* CONFIG_MMIOTRACE_HOOKS */ - -/* returns non-zero if do_page_fault() should return */ -static inline int call_mmiotrace(struct pt_regs *regs, - unsigned long error_code, - unsigned long address) +static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr) { #ifdef CONFIG_MMIOTRACE_HOOKS - int ret = 0; - rcu_read_lock(); - if (mmiotrace_pf_handler) - ret = mmiotrace_pf_handler(regs, error_code, address); - rcu_read_unlock(); - return ret; -#else - return 0; + if (unlikely(is_kmmio_active())) + if (kmmio_handler(regs, addr) == 1) + return -1; #endif + return 0; } static inline int notify_page_fault(struct pt_regs *regs) @@ -657,7 +612,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; - if (call_mmiotrace(regs, error_code, address)) + if (unlikely(kmmio_fault(regs, address))) return; /* -- cgit v1.2.3 From f294a8ce211bed7bfaca19bef21376a86200c421 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Tue, 1 Jul 2008 15:38:13 +0200 Subject: x86: small unifications of address printing 'man 3 printf' tells me that %p should be printed as if by %#x, but this is not true for the kernel, which does not use the '0x' prefix for the %p conversion specifier. A small cast to (void *) is also prettier than #ifdef/#else/#endif. Signed-off-by: Vegard Nossum Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8bcb6f40ccb..0eb70d1dd1f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -396,11 +396,7 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code, printk(KERN_CONT "NULL pointer dereference"); else printk(KERN_CONT "paging request"); -#ifdef CONFIG_X86_32 - printk(KERN_CONT " at %08lx\n", address); -#else - printk(KERN_CONT " at %016lx\n", address); -#endif + printk(KERN_CONT " at %p\n", (void *) address); printk(KERN_ALERT "IP:"); printk_address(regs->ip, 1); dump_pagetable(address); @@ -800,14 +796,10 @@ bad_area_nosemaphore: if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && printk_ratelimit()) { printk( -#ifdef CONFIG_X86_32 - "%s%s[%d]: segfault at %lx ip %08lx sp %08lx error %lx", -#else - "%s%s[%d]: segfault at %lx ip %lx sp %lx error %lx", -#endif + "%s%s[%d]: segfault at %lx ip %p sp %p error %lx", task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, - tsk->comm, task_pid_nr(tsk), address, regs->ip, - regs->sp, error_code); + tsk->comm, task_pid_nr(tsk), address, + (void *) regs->ip, (void *) regs->sp, error_code); print_vma_addr(" in ", regs->ip); printk("\n"); } -- cgit v1.2.3 From 95c60b08c6af6db2165837139da10f593462d51c Mon Sep 17 00:00:00 2001 From: Gustavo Fernando Padovan Date: Wed, 25 Jun 2008 04:03:19 -0300 Subject: x86: remove unnecessary #ifdef CONFIG_X86_32...#else Remove the #ifdef conditional because this comparison is already done in user_mode_vm(). Signed-off-by: Gustavo F. Padovan Cc: akpm@osdl.org Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8bcb6f40ccb..1e64795714c 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -55,11 +55,7 @@ static inline int notify_page_fault(struct pt_regs *regs) int ret = 0; /* kprobe_running() needs smp_processor_id() */ -#ifdef CONFIG_X86_32 if (!user_mode_vm(regs)) { -#else - if (!user_mode(regs)) { -#endif preempt_disable(); if (kprobe_running() && kprobe_fault_handler(regs, 14)) ret = 1; -- cgit v1.2.3 From 67350a5c4514c280665cdb45439d32a008a264ba Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 25 Jun 2008 00:19:11 -0400 Subject: x86: simplify vmalloc_sync_all vmalloc_sync_all() is only called from register_die_notifier and alloc_vm_area. Neither is on any performance-critical paths, so vmalloc_sync_all() itself is not on any hot paths. Given that the optimisations in vmalloc_sync_all add a fair amount of code and complexity, and are fairly hard to evaluate for correctness, it's better to just remove them to simplify the code rather than worry about its absolute performance. Signed-off-by: Jeremy Fitzhardinge Cc: xen-devel Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 77 ++++++++++++++++++----------------------------------- 1 file changed, 26 insertions(+), 51 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 578b7681955..d0f5fce77d9 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -903,14 +903,7 @@ LIST_HEAD(pgd_list); void vmalloc_sync_all(void) { #ifdef CONFIG_X86_32 - /* - * Note that races in the updates of insync and start aren't - * problematic: insync can only get set bits added, and updates to - * start are only improving performance (without affecting correctness - * if undone). - */ - static DECLARE_BITMAP(insync, PTRS_PER_PGD); - static unsigned long start = TASK_SIZE; + unsigned long start = VMALLOC_START & PGDIR_MASK; unsigned long address; if (SHARED_KERNEL_PMD) @@ -918,56 +911,38 @@ void vmalloc_sync_all(void) BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK); for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) { - if (!test_bit(pgd_index(address), insync)) { - unsigned long flags; - struct page *page; - - spin_lock_irqsave(&pgd_lock, flags); - list_for_each_entry(page, &pgd_list, lru) { - if (!vmalloc_sync_one(page_address(page), - address)) - break; - } - spin_unlock_irqrestore(&pgd_lock, flags); - if (!page) - set_bit(pgd_index(address), insync); + unsigned long flags; + struct page *page; + + spin_lock_irqsave(&pgd_lock, flags); + list_for_each_entry(page, &pgd_list, lru) { + if (!vmalloc_sync_one(page_address(page), + address)) + break; } - if (address == start && test_bit(pgd_index(address), insync)) - start = address + PGDIR_SIZE; + spin_unlock_irqrestore(&pgd_lock, flags); } #else /* CONFIG_X86_64 */ - /* - * Note that races in the updates of insync and start aren't - * problematic: insync can only get set bits added, and updates to - * start are only improving performance (without affecting correctness - * if undone). - */ - static DECLARE_BITMAP(insync, PTRS_PER_PGD); - static unsigned long start = VMALLOC_START & PGDIR_MASK; + unsigned long start = VMALLOC_START & PGDIR_MASK; unsigned long address; for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) { - if (!test_bit(pgd_index(address), insync)) { - const pgd_t *pgd_ref = pgd_offset_k(address); - unsigned long flags; - struct page *page; - - if (pgd_none(*pgd_ref)) - continue; - spin_lock_irqsave(&pgd_lock, flags); - list_for_each_entry(page, &pgd_list, lru) { - pgd_t *pgd; - pgd = (pgd_t *)page_address(page) + pgd_index(address); - if (pgd_none(*pgd)) - set_pgd(pgd, *pgd_ref); - else - BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); - } - spin_unlock_irqrestore(&pgd_lock, flags); - set_bit(pgd_index(address), insync); + const pgd_t *pgd_ref = pgd_offset_k(address); + unsigned long flags; + struct page *page; + + if (pgd_none(*pgd_ref)) + continue; + spin_lock_irqsave(&pgd_lock, flags); + list_for_each_entry(page, &pgd_list, lru) { + pgd_t *pgd; + pgd = (pgd_t *)page_address(page) + pgd_index(address); + if (pgd_none(*pgd)) + set_pgd(pgd, *pgd_ref); + else + BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); } - if (address == start) - start = address + PGDIR_SIZE; + spin_unlock_irqrestore(&pgd_lock, flags); } #endif } -- cgit v1.2.3 From 70ef56414ec7e01d787c8e959bb259845df4ee4f Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Date: Wed, 23 Jul 2008 17:36:37 +0530 Subject: x86: mm/fault.c declare do_page_fault before they get used declared do_page_fault() in asm-x86/trap.h for both X86_32 and X86_64 removed do_invalid_op declaration from mm/fault.c as it is already declared in asm-x86/trap.h Signed-off-by: Jaswinder Singh --- arch/x86/mm/fault.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 455f3fe67b4..8f92cac4e6d 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -35,6 +35,7 @@ #include #include #include +#include /* * Page fault error code bits @@ -357,8 +358,6 @@ static int is_errata100(struct pt_regs *regs, unsigned long address) return 0; } -void do_invalid_op(struct pt_regs *, unsigned long); - static int is_f00f_bug(struct pt_regs *regs, unsigned long address) { #ifdef CONFIG_X86_F00F_BUG -- cgit v1.2.3 From cc643d4687533345fd8ebcba836f9ee25df7c458 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 29 Aug 2008 12:53:45 +0100 Subject: x86: adjust vmalloc_sync_all() for Xen (2nd try) Since the fourth PDPT entry cannot be shared under Xen, vmalloc_sync_all() must iterate over pmd-s rather than pgd-s here. Luckily, the code isn't used for native PAE (SHARED_KERNEL_PMD is 1) and the change is benign to non-PAE. Also do a little more cleanup in that function. Signed-off-by: Jan Beulich Signed-off-by: Ingo Molnar Cc: Jeremy Fitzhardinge --- arch/x86/mm/fault.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 455f3fe67b4..356ed2dec3a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -915,15 +915,15 @@ LIST_HEAD(pgd_list); void vmalloc_sync_all(void) { -#ifdef CONFIG_X86_32 - unsigned long start = VMALLOC_START & PGDIR_MASK; unsigned long address; +#ifdef CONFIG_X86_32 if (SHARED_KERNEL_PMD) return; - BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK); - for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) { + for (address = VMALLOC_START & PMD_MASK; + address >= TASK_SIZE && address < FIXADDR_TOP; + address += PMD_SIZE) { unsigned long flags; struct page *page; @@ -936,10 +936,8 @@ void vmalloc_sync_all(void) spin_unlock_irqrestore(&pgd_lock, flags); } #else /* CONFIG_X86_64 */ - unsigned long start = VMALLOC_START & PGDIR_MASK; - unsigned long address; - - for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) { + for (address = VMALLOC_START & PGDIR_MASK; address <= VMALLOC_END; + address += PGDIR_SIZE) { const pgd_t *pgd_ref = pgd_offset_k(address); unsigned long flags; struct page *page; -- cgit v1.2.3 From 69c89b5bf7f253756f3056e84b8603abe1c50f5b Mon Sep 17 00:00:00 2001 From: Alexander van Heukelum Date: Fri, 26 Sep 2008 14:03:07 +0200 Subject: traps: x86: remove trace_hardirqs_fixup from pagefault handler The last use of trace_hardirqs_fixup is unnecessary, because the trap is taken with interrupt off on i386 as well as x86_64, and the irq-tracer is notified of this from the assembly code. trace_hardirqs_fixup and trace_hardirqs_fixup_flags are removed from include/asm-x86/irqflags.h as they are no longer used. Signed-off-by: Alexander van Heukelum Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index a742d753d5b..3f2b8962cbd 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -592,11 +592,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) unsigned long flags; #endif - /* - * We can fault from pretty much anywhere, with unknown IRQ state. - */ - trace_hardirqs_fixup(); - tsk = current; mm = tsk->mm; prefetchw(&mm->mmap_sem); -- cgit v1.2.3