diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 151 |
1 files changed, 129 insertions, 22 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 10d6627673cb..236120fc4dbc 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -45,9 +45,14 @@ #include <linux/personality.h> #include <linux/notifier.h> #include <trace/events/power.h> +#ifdef CONFIG_THREAD_INFO_IN_TASK +#include <linux/percpu.h> +#endif +#include <asm/alternative.h> #include <asm/compat.h> #include <asm/cacheflush.h> +#include <asm/exec.h> #include <asm/fpsimd.h> #include <asm/mmu_context.h> #include <asm/processor.h> @@ -164,6 +169,70 @@ void machine_restart(char *cmd) while (1); } +/* + * dump a block of kernel memory from around the given address + */ +static void show_data(unsigned long addr, int nbytes, const char *name) +{ + int i, j; + int nlines; + u32 *p; + + /* + * don't attempt to dump non-kernel addresses or + * values that are probably just small negative numbers + */ + if (addr < PAGE_OFFSET || addr > -256UL) + return; + + printk("\n%s: %#lx:\n", name, addr); + + /* + * round address down to a 32 bit boundary + * and always dump a multiple of 32 bytes + */ + p = (u32 *)(addr & ~(sizeof(u32) - 1)); + nbytes += (addr & (sizeof(u32) - 1)); + nlines = (nbytes + 31) / 32; + + + for (i = 0; i < nlines; i++) { + /* + * just display low 16 bits of address to keep + * each line of the dump < 80 characters + */ + printk("%04lx ", (unsigned long)p & 0xffff); + for (j = 0; j < 8; j++) { + u32 data; + if (probe_kernel_address(p, data)) { + printk(" ********"); + } else { + printk(" %08x", data); + } + ++p; + } + printk("\n"); + } +} + +static void show_extra_register_data(struct pt_regs *regs, int nbytes) +{ + mm_segment_t fs; + unsigned int i; + + fs = get_fs(); + set_fs(KERNEL_DS); + show_data(regs->pc - nbytes, nbytes * 2, "PC"); + show_data(regs->regs[30] - nbytes, nbytes * 2, "LR"); + show_data(regs->sp - nbytes, nbytes * 2, "SP"); + for (i = 0; i < 30; i++) { + char name[4]; + snprintf(name, sizeof(name), "X%u", i); + show_data(regs->regs[i] - nbytes, nbytes * 2, name); + } + set_fs(fs); +} + void __show_regs(struct pt_regs *regs) { int i, top_reg; @@ -190,6 +259,8 @@ void __show_regs(struct pt_regs *regs) if (i % 2 == 0) printk("\n"); } + if (!user_mode(regs)) + show_extra_register_data(regs, 128); printk("\n"); } @@ -199,13 +270,6 @@ void show_regs(struct pt_regs * regs) __show_regs(regs); } -/* - * Free current thread data structures etc.. - */ -void exit_thread(void) -{ -} - static void tls_thread_flush(void) { asm ("msr tpidr_el0, xzr"); @@ -289,6 +353,9 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, } else { memset(childregs, 0, sizeof(struct pt_regs)); childregs->pstate = PSR_MODE_EL1h; + if (IS_ENABLED(CONFIG_ARM64_UAO) && + cpus_have_cap(ARM64_HAS_UAO)) + childregs->pstate |= PSR_UAO_BIT; p->thread.cpu_context.x19 = stack_start; p->thread.cpu_context.x20 = stk_sz; } @@ -302,21 +369,46 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, static void tls_thread_switch(struct task_struct *next) { - unsigned long tpidr, tpidrro; + unsigned long tpidr; asm("mrs %0, tpidr_el0" : "=r" (tpidr)); *task_user_tls(current) = tpidr; - tpidr = *task_user_tls(next); - tpidrro = is_compat_thread(task_thread_info(next)) ? - next->thread.tp_value : 0; + if (is_compat_thread(task_thread_info(next))) + write_sysreg(next->thread.tp_value, tpidrro_el0); + else if (!arm64_kernel_unmapped_at_el0()) + write_sysreg(0, tpidrro_el0); + + write_sysreg(*task_user_tls(next), tpidr_el0); +} - asm( - " msr tpidr_el0, %0\n" - " msr tpidrro_el0, %1" - : : "r" (tpidr), "r" (tpidrro)); +/* Restore the UAO state depending on next's addr_limit */ +void uao_thread_switch(struct task_struct *next) +{ + if (IS_ENABLED(CONFIG_ARM64_UAO)) { + if (task_thread_info(next)->addr_limit == KERNEL_DS) + asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO)); + else + asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO)); + } } +#ifdef CONFIG_THREAD_INFO_IN_TASK +/* + * We store our current task in sp_el0, which is clobbered by userspace. Keep a + * shadow copy so that we can restore this upon entry from userspace. + * + * This is *only* for exception entry from EL0, and is not valid until we + * __switch_to() a user task. + */ +DEFINE_PER_CPU(struct task_struct *, __entry_task); + +static void entry_task_switch(struct task_struct *next) +{ + __this_cpu_write(__entry_task, next); +} +#endif + /* * Thread switching. */ @@ -329,6 +421,10 @@ struct task_struct *__switch_to(struct task_struct *prev, tls_thread_switch(next); hw_breakpoint_thread_switch(next); contextidr_thread_switch(next); +#ifdef CONFIG_THREAD_INFO_IN_TASK + entry_task_switch(next); +#endif + uao_thread_switch(next); /* * Complete any pending TLB or cache maintenance on this CPU in case @@ -345,24 +441,35 @@ struct task_struct *__switch_to(struct task_struct *prev, unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; - unsigned long stack_page; + unsigned long stack_page, ret = 0; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; + stack_page = (unsigned long)try_get_task_stack(p); + if (!stack_page) + return 0; + frame.fp = thread_saved_fp(p); frame.sp = thread_saved_sp(p); frame.pc = thread_saved_pc(p); - stack_page = (unsigned long)task_stack_page(p); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + frame.graph = p->curr_ret_stack; +#endif do { if (frame.sp < stack_page || frame.sp >= stack_page + THREAD_SIZE || - unwind_frame(&frame)) - return 0; - if (!in_sched_functions(frame.pc)) - return frame.pc; + unwind_frame(p, &frame)) + goto out; + if (!in_sched_functions(frame.pc)) { + ret = frame.pc; + goto out; + } } while (count ++ < 16); - return 0; + +out: + put_task_stack(p); + return ret; } unsigned long arch_align_stack(unsigned long sp) |