Return-path: Received: from smtprelay0051.hostedemail.com ([216.40.44.51]:52837 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751314AbeCOQ4y (ORCPT ); Thu, 15 Mar 2018 12:56:54 -0400 Message-ID: <1521133006.22221.35.camel@perches.com> (sfid-20180315_175721_754550_A71D149D) Subject: rfc: remove print_vma_addr ? (was Re: [PATCH 00/16] remove eight obsolete architectures) From: Joe Perches To: Geert Uytterhoeven , David Howells Cc: Arnd Bergmann , Linux-Arch , Linux Kernel Mailing List , linux-doc@vger.kernel.org, linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-input@vger.kernel.org, netdev , linux-wireless , Linux PWM List , linux-rtc@vger.kernel.org, linux-spi , USB list , DRI Development , Linux Fbdev development list , Linux Watchdog Mailing List , Linux FS Devel , Linux MM Date: Thu, 15 Mar 2018 09:56:46 -0700 In-Reply-To: References: <20180314143529.1456168-1-arnd@arndb.de> <2929.1521106970@warthog.procyon.org.uk> Content-Type: text/plain; charset="ISO-8859-1" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2018-03-15 at 10:48 +0100, Geert Uytterhoeven wrote: > Hi David, > > On Thu, Mar 15, 2018 at 10:42 AM, David Howells wrote: > > Do we have anything left that still implements NOMMU? > > Sure: arm, c6x, m68k, microblaze, and sh. I have a patchset that creates a vsprintf extension for print_vma_addr and removes all the uses similar to the print_symbol() removal. This now avoids any possible printk interleaving. Unfortunately, without some #ifdef in vsprintf, which I would like to avoid, it increases the nommu kernel size by ~500 bytes. Anyone think this is acceptable? Here's the overall patch, but I have it as a series --- Documentation/core-api/printk-formats.rst | 9 +++++ arch/arm64/kernel/traps.c | 13 +++---- arch/mips/mm/fault.c | 16 ++++----- arch/parisc/mm/fault.c | 15 ++++---- arch/riscv/kernel/traps.c | 11 +++--- arch/s390/mm/fault.c | 7 ++-- arch/sparc/mm/fault_32.c | 8 ++--- arch/sparc/mm/fault_64.c | 8 ++--- arch/tile/kernel/signal.c | 9 ++--- arch/um/kernel/trap.c | 13 +++---- arch/x86/kernel/signal.c | 10 ++---- arch/x86/kernel/traps.c | 18 ++++------ arch/x86/mm/fault.c | 12 +++---- include/linux/mm.h | 1 - lib/vsprintf.c | 58 ++++++++++++++++++++++++++----- mm/memory.c | 33 ------------------ 16 files changed, 112 insertions(+), 129 deletions(-) diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 934559b3c130..10a91da1bc83 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -157,6 +157,15 @@ DMA address types dma_addr_t For printing a dma_addr_t type which can vary based on build options, regardless of the width of the CPU data path. +VMA name and address +---------------------------- + +:: + + %pav [hexstart+hexsize] or ?[0+0] if unavailable + +For any address, print the vma's name and its starting address and size + Passed by reference. Raw buffer as an escaped string diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 2b478565d774..48edf812ce8b 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -242,13 +242,14 @@ void arm64_force_sig_info(struct siginfo *info, const char *str, if (!show_unhandled_signals_ratelimited()) goto send_sig; - pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk)); if (esr) - pr_cont("%s, ESR 0x%08x, ", esr_get_class_string(esr), esr); - - pr_cont("%s", str); - print_vma_addr(KERN_CONT " in ", regs->pc); - pr_cont("\n"); + pr_info("%s[%d]: unhandled exception: %s, ESR 0x%08x, %s in %pav\n", + tsk->comm, task_pid_nr(tsk), + esr_get_class_string(esr), esr, + str, ®s->pc); + else + pr_info("%s[%d]: unhandled exception: %s in %pav\n", + tsk->comm, task_pid_nr(tsk), str, ®s->pc); __show_regs(regs); send_sig: diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index 4f8f5bf46977..ce7bf077a0f5 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -213,14 +213,14 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, tsk->comm, write ? "write access to" : "read access from", field, address); - pr_info("epc = %0*lx in", field, - (unsigned long) regs->cp0_epc); - print_vma_addr(KERN_CONT " ", regs->cp0_epc); - pr_cont("\n"); - pr_info("ra = %0*lx in", field, - (unsigned long) regs->regs[31]); - print_vma_addr(KERN_CONT " ", regs->regs[31]); - pr_cont("\n"); + pr_info("epc = %0*lx in %pav\n", + field, + (unsigned long)regs->cp0_epc, + ®s->cp0_epc); + pr_info("ra = %0*lx in %pav\n", + field, + (unsigned long)regs->regs[31], + ®s->regs[31]); } current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f; info.si_signo = SIGSEGV; diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c index e247edbca68e..877cea702714 100644 --- a/arch/parisc/mm/fault.c +++ b/arch/parisc/mm/fault.c @@ -240,17 +240,14 @@ show_signal_msg(struct pt_regs *regs, unsigned long code, if (!printk_ratelimit()) return; - pr_warn("\n"); - pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx", - tsk->comm, code, address); - print_vma_addr(KERN_CONT " in ", regs->iaoq[0]); - - pr_cont("\ntrap #%lu: %s%c", code, trap_name(code), - vma ? ',':'\n'); + pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx in %pav\n", + tsk->comm, code, address, ®s->iaoq[0]); if (vma) - pr_cont(" vm_start = 0x%08lx, vm_end = 0x%08lx\n", - vma->vm_start, vma->vm_end); + pr_warn("trap #%lu: %s%c, vm_start = 0x%08lx, vm_end = 0x%08lx\n", + code, trap_name(code), vma->vm_start, vma->vm_end); + else + pr_warn("trap #%lu: %s%c\n", code, trap_name(code)); show_regs(regs); } diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 93132cb59184..16609dcb2546 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -78,12 +78,11 @@ static inline void do_trap_siginfo(int signo, int code, void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr, struct task_struct *tsk) { - if (show_unhandled_signals && unhandled_signal(tsk, signo) - && printk_ratelimit()) { - pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT, - tsk->comm, task_pid_nr(tsk), signo, code, addr); - print_vma_addr(KERN_CONT " in ", GET_IP(regs)); - pr_cont("\n"); + if (show_unhandled_signals && unhandled_signal(tsk, signo) && + printk_ratelimit()) { + pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT " in %pav\n", + tsk->comm, task_pid_nr(tsk), signo, code, addr, + &GET_IP(regs)); show_regs(regs); } diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 93faeca52284..3b1d6d618af2 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -250,10 +250,9 @@ void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault) return; if (!printk_ratelimit()) return; - printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ", - regs->int_code & 0xffff, regs->int_code >> 17); - print_vma_addr(KERN_CONT "in ", regs->psw.addr); - printk(KERN_CONT "\n"); + printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d in %pav\n", + regs->int_code & 0xffff, regs->int_code >> 17, + ®s->psw.addr); if (is_mm_fault) dump_fault_info(regs); show_regs(regs); diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c index a8103a84b4ac..206ec5a1c915 100644 --- a/arch/sparc/mm/fault_32.c +++ b/arch/sparc/mm/fault_32.c @@ -113,15 +113,11 @@ show_signal_msg(struct pt_regs *regs, int sig, int code, if (!printk_ratelimit()) return; - printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x", + printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x in %pav\n", task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, tsk->comm, task_pid_nr(tsk), address, (void *)regs->pc, (void *)regs->u_regs[UREG_I7], - (void *)regs->u_regs[UREG_FP], code); - - print_vma_addr(KERN_CONT " in ", regs->pc); - - printk(KERN_CONT "\n"); + (void *)regs->u_regs[UREG_FP], code, ®s->pc); } static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs, diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c index 41363f46797b..a21199329ebe 100644 --- a/arch/sparc/mm/fault_64.c +++ b/arch/sparc/mm/fault_64.c @@ -154,15 +154,11 @@ show_signal_msg(struct pt_regs *regs, int sig, int code, if (!printk_ratelimit()) return; - printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x", + printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x in %pav\b", task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, tsk->comm, task_pid_nr(tsk), address, (void *)regs->tpc, (void *)regs->u_regs[UREG_I7], - (void *)regs->u_regs[UREG_FP], code); - - print_vma_addr(KERN_CONT " in ", regs->tpc); - - printk(KERN_CONT "\n"); + (void *)regs->u_regs[UREG_FP], code, ®s->tpc); } static void do_fault_siginfo(int code, int sig, struct pt_regs *regs, diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c index f2bf557bb005..0556106dfe8a 100644 --- a/arch/tile/kernel/signal.c +++ b/arch/tile/kernel/signal.c @@ -383,13 +383,10 @@ void trace_unhandled_signal(const char *type, struct pt_regs *regs, if (show_unhandled_signals <= 1 && !printk_ratelimit()) return; - printk("%s%s[%d]: %s at %lx pc "REGFMT" signal %d", + printk("%s%s[%d]: %s at %lx pc " REGFMT " signal %d in %pav\n", task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, - tsk->comm, task_pid_nr(tsk), type, address, regs->pc, sig); - - print_vma_addr(KERN_CONT " in ", regs->pc); - - printk(KERN_CONT "\n"); + tsk->comm, task_pid_nr(tsk), type, address, regs->pc, sig, + ®s->pc); if (show_unhandled_signals > 1) { switch (sig) { diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index b2b02df9896e..9281248972c0 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -150,14 +150,11 @@ static void show_segv_info(struct uml_pt_regs *regs) if (!printk_ratelimit()) return; - printk("%s%s[%d]: segfault at %lx ip %px sp %px error %x", - task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, - tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi), - (void *)UPT_IP(regs), (void *)UPT_SP(regs), - fi->error_code); - - print_vma_addr(KERN_CONT " in ", UPT_IP(regs)); - printk(KERN_CONT "\n"); + printk("%s%s[%d]: segfault at %lx ip %px sp %px error %x in %pav\n", + task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, + tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi), + (void *)UPT_IP(regs), (void *)UPT_SP(regs), + fi->error_code, &UPT_IP(regs)); } static void bad_segv(struct faultinfo fi, unsigned long ip) diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 4cdc0b27ec82..9ab0c5c50b29 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -841,15 +841,11 @@ void signal_fault(struct pt_regs *regs, void __user *frame, char *where) { struct task_struct *me = current; - if (show_unhandled_signals && printk_ratelimit()) { - printk("%s" - "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", + if (show_unhandled_signals && printk_ratelimit()) + printk("%s%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx in %pav\n", task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, me->comm, me->pid, where, frame, - regs->ip, regs->sp, regs->orig_ax); - print_vma_addr(KERN_CONT " in ", regs->ip); - pr_cont("\n"); - } + regs->ip, regs->sp, regs->orig_ax, ®s->ip); force_sig(SIGSEGV, me); } diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 3d9b2308e7fa..c6e3d02759e5 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -270,13 +270,10 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, tsk->thread.trap_nr = trapnr; if (show_unhandled_signals && unhandled_signal(tsk, signr) && - printk_ratelimit()) { - pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", + printk_ratelimit()) + pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx in %pav\n", tsk->comm, tsk->pid, str, - regs->ip, regs->sp, error_code); - print_vma_addr(KERN_CONT " in ", regs->ip); - pr_cont("\n"); - } + regs->ip, regs->sp, error_code, ®s->ip); force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk); } @@ -565,13 +562,10 @@ do_general_protection(struct pt_regs *regs, long error_code) tsk->thread.trap_nr = X86_TRAP_GP; if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && - printk_ratelimit()) { - pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx", + printk_ratelimit()) + pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx in %pav\n", tsk->comm, task_pid_nr(tsk), - regs->ip, regs->sp, error_code); - print_vma_addr(KERN_CONT " in ", regs->ip); - pr_cont("\n"); - } + regs->ip, regs->sp, error_code, ®s->ip); force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); } diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e6af2b464c3d..b629319e621a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -857,14 +857,10 @@ show_signal_msg(struct pt_regs *regs, unsigned long error_code, if (!printk_ratelimit()) return; - printk("%s%s[%d]: segfault at %lx ip %px sp %px error %lx", - task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, - tsk->comm, task_pid_nr(tsk), address, - (void *)regs->ip, (void *)regs->sp, error_code); - - print_vma_addr(KERN_CONT " in ", regs->ip); - - printk(KERN_CONT "\n"); + printk("%s%s[%d]: segfault at %lx ip %px sp %px error %lx in %pav\n", + task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, + tsk->comm, task_pid_nr(tsk), address, + (void *)regs->ip, (void *)regs->sp, error_code, ®s->ip); } static void diff --git a/include/linux/mm.h b/include/linux/mm.h index 9f1270360983..9584bd3e8c25 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2537,7 +2537,6 @@ extern int randomize_va_space; #endif const char * arch_vma_name(struct vm_area_struct *vma); -void print_vma_addr(char *prefix, unsigned long rip); void sparse_mem_maps_populate_node(struct page **map_map, unsigned long pnum_begin, diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 942b5234a59b..9081476ea4ea 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -35,6 +35,8 @@ #include #include #include +#include + #ifdef CONFIG_BLOCK #include #endif @@ -407,6 +409,11 @@ struct printf_spec { #define FIELD_WIDTH_MAX ((1 << 23) - 1) #define PRECISION_MAX ((1 << 15) - 1) +static const struct printf_spec strspec = { + .field_width = -1, + .precision = -1, +}; + static noinline_for_stack char *number(char *buf, char *end, unsigned long long num, struct printf_spec spec) @@ -1427,6 +1434,45 @@ char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt) return special_hex_number(buf, end, num, size); } +static noinline_for_stack +char *vma_addr(char *buf, char *end, const void *addr) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + char *page; + char tbuf[2 * sizeof(unsigned long) * 2 + 4]; + const char *output = "?[0+0]"; + + /* + * we might be running from an atomic context so we cannot sleep + */ + if (!down_read_trylock(&mm->mmap_sem)) + goto output; + + vma = find_vma(mm, *(unsigned long *)addr); + if (!vma || !vma->vm_file) + goto up_read; + + page = (char *)__get_free_page(GFP_ATOMIC | __GFP_NOWARN); + if (page) { + char *fp; + + fp = file_path(vma->vm_file, page, PAGE_SIZE); + if (IS_ERR(fp)) + fp = "?"; + buf = string(buf, end, kbasename(fp), strspec); + sprintf(tbuf, "[%lx+%lx]", + vma->vm_start, vma->vm_end - vma->vm_start); + output = tbuf; + free_page((unsigned long)page); + } + +up_read: + up_read(&mm->mmap_sem); +output: + return string(buf, end, output, strspec); +} + static noinline_for_stack char *address_val(char *buf, char *end, const void *addr, const char *fmt) { @@ -1434,6 +1480,8 @@ char *address_val(char *buf, char *end, const void *addr, const char *fmt) int size; switch (fmt[1]) { + case 'v': + return vma_addr(buf, end, addr); case 'd': num = *(const dma_addr_t *)addr; size = sizeof(dma_addr_t); @@ -1474,11 +1522,7 @@ char *format_flags(char *buf, char *end, unsigned long flags, const struct trace_print_flags *names) { unsigned long mask; - const struct printf_spec strspec = { - .field_width = -1, - .precision = -1, - }; - const struct printf_spec numspec = { + static const struct printf_spec numspec = { .flags = SPECIAL|SMALL, .field_width = -1, .precision = -1, @@ -1548,10 +1592,6 @@ char *device_node_gen_full_name(const struct device_node *np, char *buf, char *e { int depth; const struct device_node *parent = np->parent; - static const struct printf_spec strspec = { - .field_width = -1, - .precision = -1, - }; /* special case for root node */ if (!parent) diff --git a/mm/memory.c b/mm/memory.c index bc760df8a7f4..f1f922421bde 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4502,39 +4502,6 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, } EXPORT_SYMBOL_GPL(access_process_vm); -/* - * Print the name of a VMA. - */ -void print_vma_addr(char *prefix, unsigned long ip) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - - /* - * we might be running from an atomic context so we cannot sleep - */ - if (!down_read_trylock(&mm->mmap_sem)) - return; - - vma = find_vma(mm, ip); - if (vma && vma->vm_file) { - struct file *f = vma->vm_file; - char *buf = (char *)__get_free_page(GFP_NOWAIT); - if (buf) { - char *p; - - p = file_path(f, buf, PAGE_SIZE); - if (IS_ERR(p)) - p = "?"; - printk("%s%s[%lx+%lx]", prefix, kbasename(p), - vma->vm_start, - vma->vm_end - vma->vm_start); - free_page((unsigned long)buf); - } - } - up_read(&mm->mmap_sem); -} - #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) void __might_fault(const char *file, int line) {