linux/arch/arm64/kernel/traps.c

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/*
* Based on arch/arm/kernel/traps.c
*
* Copyright (C) 1995-2009 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/bug.h>
#include <linux/signal.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <asm/atomic.h>
#include <asm/bug.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/insn.h>
#include <asm/traps.h>
#include <asm/stack_pointer.h>
#include <asm/stacktrace.h>
#include <asm/exception.h>
#include <asm/system_misc.h>
#include <asm/sysreg.h>
static const char *handler[]= {
"Synchronous Abort",
"IRQ",
"FIQ",
"Error"
};
int show_unhandled_signals = 1;
/*
* Dump out the contents of some kernel memory nicely...
*/
static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
unsigned long top)
{
unsigned long first;
mm_segment_t fs;
int i;
/*
* We need to switch to kernel mode so that we can use __get_user
* to safely read from kernel space.
*/
fs = get_fs();
set_fs(KERNEL_DS);
printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
for (first = bottom & ~31; first < top; first += 32) {
unsigned long p;
char str[sizeof(" 12345678") * 8 + 1];
memset(str, ' ', sizeof(str));
str[sizeof(str) - 1] = '\0';
for (p = first, i = 0; i < (32 / 8)
&& p < top; i++, p += 8) {
if (p >= bottom && p < top) {
arm64: modify the dump mem for 64 bit addresses On 64bit kernel, the dump_mem gives 32 bit addresses on the stack dump. This gives unorganized information regarding the 64bit values on the stack. Hence, modified to get a complete 64bit memory dump. With patch: [ 93.534801] Process insmod (pid: 1587, stack limit = 0xffffffc976be4058) [ 93.541441] Stack: (0xffffffc976be7cf0 to 0xffffffc976be8000) [ 93.547136] 7ce0: ffffffc976be7d00 ffffffc00008163c [ 93.554898] 7d00: ffffffc976be7d40 ffffffc0000f8a44 ffffffc00098ef38 ffffffbffc000088 [ 93.562659] 7d20: ffffffc00098ef50 ffffffbffc0000c0 0000000000000001 ffffffbffc000070 [ 93.570419] 7d40: ffffffc976be7e40 ffffffc0000f935c 0000000000000000 000000002b424090 [ 93.578179] 7d60: 000000002b424010 0000007facc555f4 0000000080000000 0000000000000015 [ 93.585937] 7d80: 0000000000000116 0000000000000069 ffffffc00097b000 ffffffc976be4000 [ 93.593694] 7da0: 0000000000000064 0000000000000072 000000000000006e 000000000000003f [ 93.601453] 7dc0: 000000000000feff 000000000000fff1 ffffffbffc002028 0000000000000124 [ 93.609211] 7de0: ffffffc976be7e10 0000000000000001 ffffff8000000000 ffffffbbffff0000 [ 93.616969] 7e00: ffffffc976be7e60 0000000000000000 0000000000000000 0000000000000000 [ 93.624726] 7e20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 93.632484] 7e40: 0000007fcc474550 ffffffc0000841ec 000000002b424010 0000007facda0710 [ 93.640241] 7e60: ffffffffffffffff ffffffc0000be6dc ffffff80007d2000 000000000001c010 [ 93.647999] 7e80: ffffff80007e0ae0 ffffff80007e09d0 ffffff80007edf70 0000000000000288 [ 93.655757] 7ea0: 00000000000002e8 0000000000000000 0000000000000000 0000001c0000001b [ 93.663514] 7ec0: 0000000000000009 0000000000000007 000000002b424090 000000000001c010 [ 93.671272] 7ee0: 000000002b424010 0000007faccd3a48 0000000000000000 0000000000000000 [ 93.679030] 7f00: 0000007fcc4743f8 0000007fcc4743f8 0000000000000069 0000000000000003 [ 93.686787] 7f20: 0101010101010101 0000000000000004 0000000000000020 00000000000003f3 [ 93.694544] 7f40: 0000007facb95664 0000007facda7030 0000007facc555d0 0000000000498378 [ 93.702301] 7f60: 0000000000000000 000000002b424010 0000007facda0710 000000002b424090 [ 93.710058] 7f80: 0000007fcc474698 0000000000498000 0000007fcc474ebb 0000000000474f58 [ 93.717815] 7fa0: 0000000000498000 0000000000000000 0000000000000000 0000007fcc474550 [ 93.725573] 7fc0: 00000000004104bc 0000007fcc474430 0000007facc555f4 0000000080000000 [ 93.733330] 7fe0: 000000002b424090 0000000000000069 0950020128000244 4104000008000004 [ 93.741084] Call trace: The above output makes a debugger life a lot more easier. Signed-off-by: Rohit Thapliyal <r.thapliyal@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-10 16:23:59 +08:00
unsigned long val;
if (__get_user(val, (unsigned long *)p) == 0)
sprintf(str + i * 17, " %016lx", val);
else
sprintf(str + i * 17, " ????????????????");
}
}
printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
}
set_fs(fs);
}
arm64: Synchronise dump_backtrace() with perf callchain Unlike perf callchain relying on walk_stackframe(), dump_backtrace() has its own backtrace logic. A major difference between them is the moment a symbol is recorded. Perf writes down a symbol *before* calling unwind_frame(), but dump_backtrace() prints it out *after* unwind_frame(). As a result, the last valid symbol cannot be hooked in case of dump_backtrace(). This patch addresses the issue as synchronising dump_backtrace() with perf callchain. A simple test and its results are as follows: - crash trigger $ sudo echo c > /proc/sysrq-trigger - current status Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 - with this change Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 [<fffffe00000939ec>] el0_svc_naked+0x20/0x28 Note that this patch does not cover a case where MMU is disabled. The last stack frame of swapper, for example, has PC in a form of physical address. Unfortunately, a simple conversion using phys_to_virt() cannot cover all scenarios since PC is retrieved from LR - 4, not LR. It is a big tradeoff to change both head.S and unwind_frame() for only a few of symbols in *.S. Thus, this hunk does not take care of the case. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-17 22:28:11 +08:00
static void dump_backtrace_entry(unsigned long where)
{
arm64: Synchronise dump_backtrace() with perf callchain Unlike perf callchain relying on walk_stackframe(), dump_backtrace() has its own backtrace logic. A major difference between them is the moment a symbol is recorded. Perf writes down a symbol *before* calling unwind_frame(), but dump_backtrace() prints it out *after* unwind_frame(). As a result, the last valid symbol cannot be hooked in case of dump_backtrace(). This patch addresses the issue as synchronising dump_backtrace() with perf callchain. A simple test and its results are as follows: - crash trigger $ sudo echo c > /proc/sysrq-trigger - current status Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 - with this change Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 [<fffffe00000939ec>] el0_svc_naked+0x20/0x28 Note that this patch does not cover a case where MMU is disabled. The last stack frame of swapper, for example, has PC in a form of physical address. Unfortunately, a simple conversion using phys_to_virt() cannot cover all scenarios since PC is retrieved from LR - 4, not LR. It is a big tradeoff to change both head.S and unwind_frame() for only a few of symbols in *.S. Thus, this hunk does not take care of the case. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-17 22:28:11 +08:00
/*
* Note that 'where' can have a physical address, but it's not handled.
*/
print_ip_sym(where);
}
static void __dump_instr(const char *lvl, struct pt_regs *regs)
{
unsigned long addr = instruction_pointer(regs);
char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
int i;
for (i = -4; i < 1; i++) {
unsigned int val, bad;
bad = __get_user(val, &((u32 *)addr)[i]);
if (!bad)
p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
else {
p += sprintf(p, "bad PC value");
break;
}
}
printk("%sCode: %s\n", lvl, str);
}
static void dump_instr(const char *lvl, struct pt_regs *regs)
{
if (!user_mode(regs)) {
mm_segment_t fs = get_fs();
set_fs(KERNEL_DS);
__dump_instr(lvl, regs);
set_fs(fs);
} else {
__dump_instr(lvl, regs);
}
}
static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
struct stackframe frame;
unsigned long irq_stack_ptr;
arm64: ftrace: fix a stack tracer's output under function graph tracer Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15 16:33:41 +08:00
int skip;
arm64: fix dump_backtrace/unwind_frame with NULL tsk In some places, dump_backtrace() is called with a NULL tsk parameter, e.g. in bug_handler() in arch/arm64, or indirectly via show_stack() in core code. The expectation is that this is treated as if current were passed instead of NULL. Similar is true of unwind_frame(). Commit a80a0eb70c358f8c ("arm64: make irq_stack_ptr more robust") didn't take this into account. In dump_backtrace() it compares tsk against current *before* we check if tsk is NULL, and in unwind_frame() we never set tsk if it is NULL. Due to this, we won't initialise irq_stack_ptr in either function. In dump_backtrace() this results in calling dump_mem() for memory immediately above the IRQ stack range, rather than for the relevant range on the task stack. In unwind_frame we'll reject unwinding frames on the IRQ stack. In either case this results in incomplete or misleading backtrace information, but is not otherwise problematic. The initial percpu areas (including the IRQ stacks) are allocated in the linear map, and dump_mem uses __get_user(), so we shouldn't access anything with side-effects, and will handle holes safely. This patch fixes the issue by having both functions handle the NULL tsk case before doing anything else with tsk. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Fixes: a80a0eb70c358f8c ("arm64: make irq_stack_ptr more robust") Acked-by: James Morse <james.morse@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yang Shi <yang.shi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-24 00:55:05 +08:00
pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
if (!tsk)
tsk = current;
if (!try_get_task_stack(tsk))
return;
/*
* Switching between stacks is valid when tracing current and in
* non-preemptible context.
*/
if (tsk == current && !preemptible())
irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
else
irq_stack_ptr = 0;
arm64: ftrace: fix a stack tracer's output under function graph tracer Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15 16:33:41 +08:00
if (tsk == current) {
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.sp = current_stack_pointer;
frame.pc = (unsigned long)dump_backtrace;
} else {
/*
* task blocked in __switch_to
*/
frame.fp = thread_saved_fp(tsk);
frame.sp = thread_saved_sp(tsk);
frame.pc = thread_saved_pc(tsk);
}
arm64: ftrace: fix a stack tracer's output under function graph tracer Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15 16:33:41 +08:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = tsk->curr_ret_stack;
#endif
arm64: ftrace: fix a stack tracer's output under function graph tracer Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15 16:33:41 +08:00
skip = !!regs;
printk("Call trace:\n");
while (1) {
unsigned long where = frame.pc;
arm64: Synchronise dump_backtrace() with perf callchain Unlike perf callchain relying on walk_stackframe(), dump_backtrace() has its own backtrace logic. A major difference between them is the moment a symbol is recorded. Perf writes down a symbol *before* calling unwind_frame(), but dump_backtrace() prints it out *after* unwind_frame(). As a result, the last valid symbol cannot be hooked in case of dump_backtrace(). This patch addresses the issue as synchronising dump_backtrace() with perf callchain. A simple test and its results are as follows: - crash trigger $ sudo echo c > /proc/sysrq-trigger - current status Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 - with this change Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 [<fffffe00000939ec>] el0_svc_naked+0x20/0x28 Note that this patch does not cover a case where MMU is disabled. The last stack frame of swapper, for example, has PC in a form of physical address. Unfortunately, a simple conversion using phys_to_virt() cannot cover all scenarios since PC is retrieved from LR - 4, not LR. It is a big tradeoff to change both head.S and unwind_frame() for only a few of symbols in *.S. Thus, this hunk does not take care of the case. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-17 22:28:11 +08:00
unsigned long stack;
int ret;
arm64: ftrace: fix a stack tracer's output under function graph tracer Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15 16:33:41 +08:00
/* skip until specified stack frame */
if (!skip) {
dump_backtrace_entry(where);
} else if (frame.fp == regs->regs[29]) {
skip = 0;
/*
* Mostly, this is the case where this function is
* called in panic/abort. As exception handler's
* stack frame does not contain the corresponding pc
* at which an exception has taken place, use regs->pc
* instead.
*/
dump_backtrace_entry(regs->pc);
}
ret = unwind_frame(tsk, &frame);
if (ret < 0)
break;
arm64: Synchronise dump_backtrace() with perf callchain Unlike perf callchain relying on walk_stackframe(), dump_backtrace() has its own backtrace logic. A major difference between them is the moment a symbol is recorded. Perf writes down a symbol *before* calling unwind_frame(), but dump_backtrace() prints it out *after* unwind_frame(). As a result, the last valid symbol cannot be hooked in case of dump_backtrace(). This patch addresses the issue as synchronising dump_backtrace() with perf callchain. A simple test and its results are as follows: - crash trigger $ sudo echo c > /proc/sysrq-trigger - current status Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 - with this change Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 [<fffffe00000939ec>] el0_svc_naked+0x20/0x28 Note that this patch does not cover a case where MMU is disabled. The last stack frame of swapper, for example, has PC in a form of physical address. Unfortunately, a simple conversion using phys_to_virt() cannot cover all scenarios since PC is retrieved from LR - 4, not LR. It is a big tradeoff to change both head.S and unwind_frame() for only a few of symbols in *.S. Thus, this hunk does not take care of the case. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-17 22:28:11 +08:00
stack = frame.sp;
if (in_exception_text(where)) {
/*
* If we switched to the irq_stack before calling this
* exception handler, then the pt_regs will be on the
* task stack. The easiest way to tell is if the large
* pt_regs would overlap with the end of the irq_stack.
*/
if (stack < irq_stack_ptr &&
(stack + sizeof(struct pt_regs)) > irq_stack_ptr)
stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);
arm64: Synchronise dump_backtrace() with perf callchain Unlike perf callchain relying on walk_stackframe(), dump_backtrace() has its own backtrace logic. A major difference between them is the moment a symbol is recorded. Perf writes down a symbol *before* calling unwind_frame(), but dump_backtrace() prints it out *after* unwind_frame(). As a result, the last valid symbol cannot be hooked in case of dump_backtrace(). This patch addresses the issue as synchronising dump_backtrace() with perf callchain. A simple test and its results are as follows: - crash trigger $ sudo echo c > /proc/sysrq-trigger - current status Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 - with this change Call trace: [<fffffe00003dc738>] sysrq_handle_crash+0x24/0x30 [<fffffe00003dd2ac>] __handle_sysrq+0x128/0x19c [<fffffe00003dd730>] write_sysrq_trigger+0x60/0x74 [<fffffe0000249fc4>] proc_reg_write+0x84/0xc0 [<fffffe00001f2638>] __vfs_write+0x44/0x104 [<fffffe00001f2e60>] vfs_write+0x98/0x1a8 [<fffffe00001f3730>] SyS_write+0x50/0xb0 [<fffffe00000939ec>] el0_svc_naked+0x20/0x28 Note that this patch does not cover a case where MMU is disabled. The last stack frame of swapper, for example, has PC in a form of physical address. Unfortunately, a simple conversion using phys_to_virt() cannot cover all scenarios since PC is retrieved from LR - 4, not LR. It is a big tradeoff to change both head.S and unwind_frame() for only a few of symbols in *.S. Thus, this hunk does not take care of the case. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-17 22:28:11 +08:00
dump_mem("", "Exception stack", stack,
stack + sizeof(struct pt_regs));
}
}
put_task_stack(tsk);
}
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
barrier();
}
#ifdef CONFIG_PREEMPT
#define S_PREEMPT " PREEMPT"
#else
#define S_PREEMPT ""
#endif
#define S_SMP " SMP"
static int __die(const char *str, int err, struct pt_regs *regs)
{
struct task_struct *tsk = current;
static int die_counter;
int ret;
pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
str, err, ++die_counter);
/* trap and error numbers are mostly meaningless on ARM */
ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
if (ret == NOTIFY_STOP)
return ret;
print_modules();
__show_regs(regs);
pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
end_of_stack(tsk));
if (!user_mode(regs)) {
dump_mem(KERN_EMERG, "Stack: ", regs->sp,
THREAD_SIZE + (unsigned long)task_stack_page(tsk));
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return ret;
}
static DEFINE_RAW_SPINLOCK(die_lock);
/*
* This function is protected against re-entrancy.
*/
void die(const char *str, struct pt_regs *regs, int err)
{
int ret;
oops_enter();
raw_spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
ret = __die(str, err, regs);
if (regs && kexec_should_crash(current))
crash_kexec(regs);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
raw_spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (ret != NOTIFY_STOP)
do_exit(SIGSEGV);
}
void arm64_notify_die(const char *str, struct pt_regs *regs,
struct siginfo *info, int err)
{
if (user_mode(regs)) {
current->thread.fault_address = 0;
current->thread.fault_code = err;
force_sig_info(info->si_signo, info, current);
} else {
die(str, regs, err);
}
}
static LIST_HEAD(undef_hook);
static DEFINE_RAW_SPINLOCK(undef_lock);
void register_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
raw_spin_lock_irqsave(&undef_lock, flags);
list_add(&hook->node, &undef_hook);
raw_spin_unlock_irqrestore(&undef_lock, flags);
}
void unregister_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
raw_spin_lock_irqsave(&undef_lock, flags);
list_del(&hook->node);
raw_spin_unlock_irqrestore(&undef_lock, flags);
}
static int call_undef_hook(struct pt_regs *regs)
{
struct undef_hook *hook;
unsigned long flags;
u32 instr;
int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
void __user *pc = (void __user *)instruction_pointer(regs);
if (!user_mode(regs))
return 1;
if (compat_thumb_mode(regs)) {
/* 16-bit Thumb instruction */
if (get_user(instr, (u16 __user *)pc))
goto exit;
instr = le16_to_cpu(instr);
if (aarch32_insn_is_wide(instr)) {
u32 instr2;
if (get_user(instr2, (u16 __user *)(pc + 2)))
goto exit;
instr2 = le16_to_cpu(instr2);
instr = (instr << 16) | instr2;
}
} else {
/* 32-bit ARM instruction */
if (get_user(instr, (u32 __user *)pc))
goto exit;
instr = le32_to_cpu(instr);
}
raw_spin_lock_irqsave(&undef_lock, flags);
list_for_each_entry(hook, &undef_hook, node)
if ((instr & hook->instr_mask) == hook->instr_val &&
(regs->pstate & hook->pstate_mask) == hook->pstate_val)
fn = hook->fn;
raw_spin_unlock_irqrestore(&undef_lock, flags);
exit:
return fn ? fn(regs, instr) : 1;
}
static void force_signal_inject(int signal, int code, struct pt_regs *regs,
unsigned long address)
{
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
const char *desc;
switch (signal) {
case SIGILL:
desc = "undefined instruction";
break;
case SIGSEGV:
desc = "illegal memory access";
break;
default:
desc = "bad mode";
break;
}
if (unhandled_signal(current, signal) &&
show_unhandled_signals_ratelimited()) {
pr_info("%s[%d]: %s: pc=%p\n",
current->comm, task_pid_nr(current), desc, pc);
dump_instr(KERN_INFO, regs);
}
info.si_signo = signal;
info.si_errno = 0;
info.si_code = code;
info.si_addr = pc;
arm64_notify_die(desc, regs, &info, 0);
}
/*
* Set up process info to signal segmentation fault - called on access error.
*/
void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr)
{
int code;
down_read(&current->mm->mmap_sem);
if (find_vma(current->mm, addr) == NULL)
code = SEGV_MAPERR;
else
code = SEGV_ACCERR;
up_read(&current->mm->mmap_sem);
force_signal_inject(SIGSEGV, code, regs, addr);
}
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
/* check for AArch32 breakpoint instructions */
if (!aarch32_break_handler(regs))
return;
if (call_undef_hook(regs) == 0)
return;
force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0);
}
int cpu_enable_cache_maint_trap(void *__unused)
{
config_sctlr_el1(SCTLR_EL1_UCI, 0);
return 0;
}
#define __user_cache_maint(insn, address, res) \
if (untagged_addr(address) >= user_addr_max()) { \
res = -EFAULT; \
} else { \
uaccess_ttbr0_enable(); \
asm volatile ( \
"1: " insn ", %1\n" \
" mov %w0, #0\n" \
"2:\n" \
" .pushsection .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %w0, %w2\n" \
" b 2b\n" \
" .popsection\n" \
_ASM_EXTABLE(1b, 3b) \
: "=r" (res) \
: "r" (address), "i" (-EFAULT)); \
uaccess_ttbr0_disable(); \
}
static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
{
unsigned long address;
int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT;
int ret = 0;
address = (rt == 31) ? 0 : regs->regs[rt];
switch (crm) {
case ESR_ELx_SYS64_ISS_CRM_DC_CVAU: /* DC CVAU, gets promoted */
__user_cache_maint("dc civac", address, ret);
break;
case ESR_ELx_SYS64_ISS_CRM_DC_CVAC: /* DC CVAC, gets promoted */
__user_cache_maint("dc civac", address, ret);
break;
case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC: /* DC CIVAC */
__user_cache_maint("dc civac", address, ret);
break;
case ESR_ELx_SYS64_ISS_CRM_IC_IVAU: /* IC IVAU */
__user_cache_maint("ic ivau", address, ret);
break;
default:
force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0);
return;
}
if (ret)
arm64_notify_segfault(regs, address);
else
regs->pc += 4;
}
static void ctr_read_handler(unsigned int esr, struct pt_regs *regs)
{
int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
regs->regs[rt] = arm64_ftr_reg_ctrel0.sys_val;
regs->pc += 4;
}
struct sys64_hook {
unsigned int esr_mask;
unsigned int esr_val;
void (*handler)(unsigned int esr, struct pt_regs *regs);
};
static struct sys64_hook sys64_hooks[] = {
{
.esr_mask = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_MASK,
.esr_val = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_VAL,
.handler = user_cache_maint_handler,
},
{
/* Trap read access to CTR_EL0 */
.esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK,
.esr_val = ESR_ELx_SYS64_ISS_SYS_CTR_READ,
.handler = ctr_read_handler,
},
{},
};
asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs)
{
struct sys64_hook *hook;
for (hook = sys64_hooks; hook->handler; hook++)
if ((hook->esr_mask & esr) == hook->esr_val) {
hook->handler(esr, regs);
return;
}
force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0);
}
long compat_arm_syscall(struct pt_regs *regs);
asmlinkage long do_ni_syscall(struct pt_regs *regs)
{
#ifdef CONFIG_COMPAT
long ret;
if (is_compat_task()) {
ret = compat_arm_syscall(regs);
if (ret != -ENOSYS)
return ret;
}
#endif
if (show_unhandled_signals_ratelimited()) {
pr_info("%s[%d]: syscall %d\n", current->comm,
task_pid_nr(current), (int)regs->syscallno);
dump_instr("", regs);
if (user_mode(regs))
__show_regs(regs);
}
return sys_ni_syscall();
}
static const char *esr_class_str[] = {
[0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC",
[ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized",
[ESR_ELx_EC_WFx] = "WFI/WFE",
[ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC",
[ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC",
[ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC",
[ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC",
[ESR_ELx_EC_FP_ASIMD] = "ASIMD",
[ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS",
[ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC",
[ESR_ELx_EC_ILL] = "PSTATE.IL",
[ESR_ELx_EC_SVC32] = "SVC (AArch32)",
[ESR_ELx_EC_HVC32] = "HVC (AArch32)",
[ESR_ELx_EC_SMC32] = "SMC (AArch32)",
[ESR_ELx_EC_SVC64] = "SVC (AArch64)",
[ESR_ELx_EC_HVC64] = "HVC (AArch64)",
[ESR_ELx_EC_SMC64] = "SMC (AArch64)",
[ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)",
[ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF",
[ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)",
[ESR_ELx_EC_IABT_CUR] = "IABT (current EL)",
[ESR_ELx_EC_PC_ALIGN] = "PC Alignment",
[ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)",
[ESR_ELx_EC_DABT_CUR] = "DABT (current EL)",
[ESR_ELx_EC_SP_ALIGN] = "SP Alignment",
[ESR_ELx_EC_FP_EXC32] = "FP (AArch32)",
[ESR_ELx_EC_FP_EXC64] = "FP (AArch64)",
[ESR_ELx_EC_SERROR] = "SError",
[ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)",
[ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)",
[ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)",
[ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)",
[ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)",
[ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)",
[ESR_ELx_EC_BKPT32] = "BKPT (AArch32)",
[ESR_ELx_EC_VECTOR32] = "Vector catch (AArch32)",
[ESR_ELx_EC_BRK64] = "BRK (AArch64)",
};
const char *esr_get_class_string(u32 esr)
{
return esr_class_str[ESR_ELx_EC(esr)];
}
/*
* bad_mode handles the impossible case in the exception vector.
*/
asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
{
siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);
console_verbose();
pr_crit("Bad mode in %s handler detected on CPU%d, code 0x%08x -- %s\n",
handler[reason], smp_processor_id(), esr,
esr_get_class_string(esr));
__show_regs(regs);
info.si_signo = SIGILL;
info.si_errno = 0;
info.si_code = ILL_ILLOPC;
info.si_addr = pc;
arm64_notify_die("Oops - bad mode", regs, &info, 0);
}
void __pte_error(const char *file, int line, unsigned long val)
{
pr_err("%s:%d: bad pte %016lx.\n", file, line, val);
}
void __pmd_error(const char *file, int line, unsigned long val)
{
pr_err("%s:%d: bad pmd %016lx.\n", file, line, val);
}
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 17:40:51 +08:00
void __pud_error(const char *file, int line, unsigned long val)
{
pr_err("%s:%d: bad pud %016lx.\n", file, line, val);
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 17:40:51 +08:00
}
void __pgd_error(const char *file, int line, unsigned long val)
{
pr_err("%s:%d: bad pgd %016lx.\n", file, line, val);
}
/* GENERIC_BUG traps */
int is_valid_bugaddr(unsigned long addr)
{
/*
* bug_handler() only called for BRK #BUG_BRK_IMM.
* So the answer is trivial -- any spurious instances with no
* bug table entry will be rejected by report_bug() and passed
* back to the debug-monitors code and handled as a fatal
* unexpected debug exception.
*/
return 1;
}
static int bug_handler(struct pt_regs *regs, unsigned int esr)
{
if (user_mode(regs))
return DBG_HOOK_ERROR;
switch (report_bug(regs->pc, regs)) {
case BUG_TRAP_TYPE_BUG:
die("Oops - BUG", regs, 0);
break;
case BUG_TRAP_TYPE_WARN:
/* Ideally, report_bug() should backtrace for us... but no. */
dump_backtrace(regs, NULL);
break;
default:
/* unknown/unrecognised bug trap type */
return DBG_HOOK_ERROR;
}
/* If thread survives, skip over the BUG instruction and continue: */
regs->pc += AARCH64_INSN_SIZE; /* skip BRK and resume */
return DBG_HOOK_HANDLED;
}
static struct break_hook bug_break_hook = {
.esr_val = 0xf2000000 | BUG_BRK_IMM,
.esr_mask = 0xffffffff,
.fn = bug_handler,
};
/*
* Initial handler for AArch64 BRK exceptions
* This handler only used until debug_traps_init().
*/
int __init early_brk64(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
}
/* This registration must happen early, before debug_traps_init(). */
void __init trap_init(void)
{
register_break_hook(&bug_break_hook);
}