From 89e3f23da9c827bfa9806c3d4da83a12c1c8543a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 30 Apr 2013 15:27:10 -0700 Subject: sparc32: make show_stack() acquire %fp if @_ksp is not specified show_stack(current or NULL, NULL) is used by arch-independent code to dump backtrace of the current task; however, sparc32 show_stack() doesn't implement it and wouldn't print any backtrace when NULL @_ksp is specfied. Make show_stack() acquire and use %fp if @tsk is NULL or current and @_ksp is NULL. This makes %fp fetching in dump_stack() unnecessary. Make it use NULL for @_ksp instead. Only compile tested. Signed-off-by: Tejun Heo Acked-by: David S. Miller Cc: Bjorn Helgaas Cc: Fengguang Wu Cc: Heiko Carstens Cc: Jesper Nilsson Cc: Martin Schwidefsky Cc: Mike Frysinger Cc: Vineet Gupta Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc/kernel/process_32.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'arch/sparc/kernel') diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index c85241006e32..2be4214b3905 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -142,11 +142,13 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp) struct reg_window32 *rw; int count = 0; - if (tsk != NULL) - task_base = (unsigned long) task_stack_page(tsk); - else - task_base = (unsigned long) current_thread_info(); + if (!tsk) + tsk = current; + if (tsk == current && !_ksp) + __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); + + task_base = (unsigned long) task_stack_page(tsk); fp = (unsigned long) _ksp; do { /* Bogus frame pointer? */ @@ -164,11 +166,7 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp) void dump_stack(void) { - unsigned long *ksp; - - __asm__ __volatile__("mov %%fp, %0" - : "=r" (ksp)); - show_stack(current, ksp); + show_stack(current, NULL); } EXPORT_SYMBOL(dump_stack); -- cgit v1.2.2 From 196779b9b4ce1922afabdc20d0270720603bd46c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 30 Apr 2013 15:27:12 -0700 Subject: dump_stack: consolidate dump_stack() implementations and unify their behaviors Both dump_stack() and show_stack() are currently implemented by each architecture. show_stack(NULL, NULL) dumps the backtrace for the current task as does dump_stack(). On some archs, dump_stack() prints extra information - pid, utsname and so on - in addition to the backtrace while the two are identical on other archs. The usages in arch-independent code of the two functions indicate show_stack(NULL, NULL) should print out bare backtrace while dump_stack() is used for debugging purposes when something went wrong, so it does make sense to print additional information on the task which triggered dump_stack(). There's no reason to require archs to implement two separate but mostly identical functions. It leads to unnecessary subtle information. This patch expands the dummy fallback dump_stack() implementation in lib/dump_stack.c such that it prints out debug information (taken from x86) and invokes show_stack(NULL, NULL) and drops arch-specific dump_stack() implementations in all archs except blackfin. Blackfin's dump_stack() does something wonky that I don't understand. Debug information can be printed separately by calling dump_stack_print_info() so that arch-specific dump_stack() implementation can still emit the same debug information. This is used in blackfin. This patch brings the following behavior changes. * On some archs, an extra level in backtrace for show_stack() could be printed. This is because the top frame was determined in dump_stack() on those archs while generic dump_stack() can't do that reliably. It can be compensated by inlining dump_stack() but not sure whether that'd be necessary. * Most archs didn't use to print debug info on dump_stack(). They do now. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Hardware name: empty Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [] dump_stack+0x19/0x1b [] warn_slowpath_common+0x7f/0xc0 [] warn_slowpath_null+0x1a/0x20 [] init_workqueues+0x35/0x505 ... v2: CPU number added to the generic debug info as requested by s390 folks and dropped the s390 specific dump_stack(). This loses %ksp from the debug message which the maintainers think isn't important enough to keep the s390-specific dump_stack() implementation. dump_stack_print_info() is moved to kernel/printk.c from lib/dump_stack.c. Because linkage is per objecct file, dump_stack_print_info() living in the same lib file as generic dump_stack() means that archs which implement custom dump_stack() - at this point, only blackfin - can't use dump_stack_print_info() as that will bring in the generic version of dump_stack() too. v1 The v1 patch broke build on blackfin due to this issue. The build breakage was reported by Fengguang Wu. Signed-off-by: Tejun Heo Acked-by: David S. Miller Acked-by: Vineet Gupta Acked-by: Jesper Nilsson Acked-by: Vineet Gupta Acked-by: Martin Schwidefsky [s390 bits] Cc: Heiko Carstens Cc: Mike Frysinger Cc: Fengguang Wu Cc: Bjorn Helgaas Cc: Sam Ravnborg Acked-by: Richard Kuo [hexagon bits] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc/kernel/process_32.c | 7 ------- arch/sparc/kernel/traps_64.c | 7 ------- 2 files changed, 14 deletions(-) (limited to 'arch/sparc/kernel') diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 2be4214b3905..dccf5f58d70f 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -164,13 +164,6 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp) printk("\n"); } -void dump_stack(void) -{ - show_stack(current, NULL); -} - -EXPORT_SYMBOL(dump_stack); - /* * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. */ diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index 8d38ca97aa23..b3f833ab90eb 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -2350,13 +2350,6 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp) } while (++count < 16); } -void dump_stack(void) -{ - show_stack(current, NULL); -} - -EXPORT_SYMBOL(dump_stack); - static inline struct reg_window *kernel_stack_up(struct reg_window *rw) { unsigned long fp = rw->ins[6]; -- cgit v1.2.2 From a43cb95d547a061ed5bf1acb28e0f5fd575e26c1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 30 Apr 2013 15:27:17 -0700 Subject: dump_stack: unify debug information printed by show_regs() show_regs() is inherently arch-dependent but it does make sense to print generic debug information and some archs already do albeit in slightly different forms. This patch introduces a generic function to print debug information from show_regs() so that different archs print out the same information and it's much easier to modify what's printed. show_regs_print_info() prints out the same debug info as dump_stack() does plus task and thread_info pointers. * Archs which didn't print debug info now do. alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r, metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc, um, xtensa * Already prints debug info. Replaced with show_regs_print_info(). The printed information is superset of what used to be there. arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86 * s390 is special in that it used to print arch-specific information along with generic debug info. Heiko and Martin think that the arch-specific extra isn't worth keeping s390 specfic implementation. Converted to use the generic version. Note that now all archs print the debug info before actual register dumps. An example BUG() dump follows. kernel BUG at /work/os/work/kernel/workqueue.c:4841! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000 RIP: 0010:[] [] init_workqueues+0x4/0x6 RSP: 0000:ffff88007c861ec8 EFLAGS: 00010246 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760 Call Trace: [] do_one_initcall+0x122/0x170 [] kernel_init_freeable+0x9b/0x1c8 [] ? rest_init+0x140/0x140 [] kernel_init+0xe/0xf0 [] ret_from_fork+0x7c/0xb0 [] ? rest_init+0x140/0x140 ... v2: Typo fix in x86-32. v3: CPU number dropped from show_regs_print_info() as dump_stack_print_info() has been updated to print it. s390 specific implementation dropped as requested by s390 maintainers. Signed-off-by: Tejun Heo Acked-by: David S. Miller Acked-by: Jesper Nilsson Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Bjorn Helgaas Cc: Fengguang Wu Cc: Mike Frysinger Cc: Vineet Gupta Cc: Sam Ravnborg Acked-by: Chris Metcalf [tile bits] Acked-by: Richard Kuo [hexagon bits] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc/kernel/process_32.c | 2 ++ arch/sparc/kernel/process_64.c | 2 ++ 2 files changed, 4 insertions(+) (limited to 'arch/sparc/kernel') diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index dccf5f58d70f..fdd819dfdacf 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -112,6 +112,8 @@ void show_regs(struct pt_regs *r) { struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; + show_regs_print_info(KERN_DEFAULT); + printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", r->psr, r->pc, r->npc, r->y, print_tainted()); printk("PC: <%pS>\n", (void *) r->pc); diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 9fbf0d14a361..c6dc1ba069ca 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -163,6 +163,8 @@ static void show_regwindow(struct pt_regs *regs) void show_regs(struct pt_regs *regs) { + show_regs_print_info(KERN_DEFAULT); + printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate, regs->tpc, regs->tnpc, regs->y, print_tainted()); printk("TPC: <%pS>\n", (void *) regs->tpc); -- cgit v1.2.2 From 5452c7f8c7e12c191b7e2d2a58476ab41e0387aa Mon Sep 17 00:00:00 2001 From: "zhangwei(Jovi)" Date: Tue, 30 Apr 2013 15:28:55 -0700 Subject: sparc/sysrq: fix inconstistent help message of sysrq key Currently help message of /proc/sysrq-trigger highlight its upper-case characters, like below: SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) ... this would confuse user trigger sysrq by upper-case character, which is inconsistent with the real lower-case character registed key. This inconsistent help message will also lead more confused when 26 upper-case letters put into use in future. This patch fix spare sysrq key: "global-regs(y)" Signed-off-by: zhangwei(Jovi) Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc/kernel/process_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/sparc/kernel') diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index c6dc1ba069ca..baebab215492 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -294,7 +294,7 @@ static void sysrq_handle_globreg(int key) static struct sysrq_key_op sparc_globalreg_op = { .handler = sysrq_handle_globreg, - .help_msg = "global-regs(Y)", + .help_msg = "global-regs(y)", .action_msg = "Show Global CPU Regs", }; @@ -364,7 +364,7 @@ static void sysrq_handle_globpmu(int key) static struct sysrq_key_op sparc_globalpmu_op = { .handler = sysrq_handle_globpmu, - .help_msg = "global-pmu(X)", + .help_msg = "global-pmu(x)", .action_msg = "Show Global PMU Regs", }; -- cgit v1.2.2