From: Eric W. Biederman Date: Thu, 2 Feb 2023 04:42:42 +0000 (-0800) Subject: exit: Add and use make_task_dead. X-Git-Tag: baikal/aarch64/sdk5.9~19 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=b052a3f3a4a7924951d912d355045707ca7e2bb1;p=kernel.git exit: Add and use make_task_dead. commit 238bcd2dab757a27f9590b792c4f766b7519fe28 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin --- diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c index f6b9664ac5042..f87d8e1fcfe42 100644 --- a/arch/alpha/kernel/traps.c +++ b/arch/alpha/kernel/traps.c @@ -192,7 +192,7 @@ die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15) local_irq_enable(); while (1); } - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } #ifndef CONFIG_MATHEMU @@ -577,7 +577,7 @@ do_entUna(void * va, unsigned long opcode, unsigned long reg, printk("Bad unaligned kernel access at %016lx: %p %lx %lu\n", pc, va, opcode, reg); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); got_exception: /* Ok, we caught the exception, but we don't want it. Is there @@ -632,7 +632,7 @@ got_exception: local_irq_enable(); while (1); } - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } /* diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c index 741e61ef9d3fe..a86286d2d3f3f 100644 --- a/arch/alpha/mm/fault.c +++ b/arch/alpha/mm/fault.c @@ -206,7 +206,7 @@ retry: printk(KERN_ALERT "Unable to handle kernel paging request at " "virtual address %016lx\n", address); die_if_kernel("Oops", regs, cause, (unsigned long*)regs - 16); - do_exit(SIGKILL); + make_task_dead(SIGKILL); /* We ran out of memory, or some other thing happened to us that made us unable to handle the page fault gracefully. */ diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 207ef9a797bd4..03dfeb1208431 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -341,7 +341,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) if (panic_on_oops) panic("Fatal exception"); if (signr) - do_exit(signr); + make_task_dead(signr); } /* diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index bd0f4821f7e11..d623932437208 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -124,7 +124,7 @@ __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, show_pte(KERN_ALERT, mm, addr); die("Oops", regs, fsr); bust_spinlocks(0); - do_exit(SIGKILL); + make_task_dead(SIGKILL); } /* diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 4e3e9d9c81517..a436a6972ced7 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -202,7 +202,7 @@ void die(const char *str, struct pt_regs *regs, int err) raw_spin_unlock_irqrestore(&die_lock, flags); if (ret != NOTIFY_STOP) - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } static void arm64_show_signal(int signo, const char *str) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 2a7339aeb1ad4..a8e9c98147a19 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -296,7 +296,7 @@ static void die_kernel_fault(const char *msg, unsigned long addr, show_pte(addr); die("Oops", regs, esr); bust_spinlocks(0); - do_exit(SIGKILL); + make_task_dead(SIGKILL); } static void __do_kernel_fault(unsigned long addr, unsigned int esr, diff --git a/arch/csky/abiv1/alignment.c b/arch/csky/abiv1/alignment.c index cb2a0d94a144d..5e2fb45d605cf 100644 --- a/arch/csky/abiv1/alignment.c +++ b/arch/csky/abiv1/alignment.c @@ -294,7 +294,7 @@ bad_area: __func__, opcode, rz, rx, imm, addr); show_regs(regs); bust_spinlocks(0); - do_exit(SIGKILL); + make_dead_task(SIGKILL); } force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr); diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c index 63715cb90ee99..af7562907f7fa 100644 --- a/arch/csky/kernel/traps.c +++ b/arch/csky/kernel/traps.c @@ -85,7 +85,7 @@ void die_if_kernel(char *str, struct pt_regs *regs, int nr) pr_err("%s: %08x\n", str, nr); show_regs(regs); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); - do_exit(SIGSEGV); + make_dead_task(SIGSEGV); } void buserr(struct pt_regs *regs) diff --git a/arch/h8300/kernel/traps.c b/arch/h8300/kernel/traps.c index e47a9e0dc278f..a284c126f07a6 100644 --- a/arch/h8300/kernel/traps.c +++ b/arch/h8300/kernel/traps.c @@ -110,7 +110,7 @@ void die(const char *str, struct pt_regs *fp, unsigned long err) dump(fp); spin_unlock_irq(&die_lock); - do_exit(SIGSEGV); + make_dead_task(SIGSEGV); } static int kstack_depth_to_print = 24; diff --git a/arch/h8300/mm/fault.c b/arch/h8300/mm/fault.c index fabffb83930af..a8d8fc63780e4 100644 --- a/arch/h8300/mm/fault.c +++ b/arch/h8300/mm/fault.c @@ -52,7 +52,7 @@ asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address, printk(" at virtual address %08lx\n", address); if (!user_mode(regs)) die("Oops", regs, error_code); - do_exit(SIGKILL); + make_dead_task(SIGKILL); return 1; } diff --git a/arch/hexagon/kernel/traps.c b/arch/hexagon/kernel/traps.c index 69c623b14ddd2..bfd04a388bcac 100644 --- a/arch/hexagon/kernel/traps.c +++ b/arch/hexagon/kernel/traps.c @@ -221,7 +221,7 @@ int die(const char *str, struct pt_regs *regs, long err) panic("Fatal exception"); oops_exit(); - do_exit(err); + make_dead_task(err); return 0; } diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c index 2a40268c3d494..c8a87798618ed 100644 --- a/arch/ia64/kernel/mca_drv.c +++ b/arch/ia64/kernel/mca_drv.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -176,7 +177,7 @@ mca_handler_bh(unsigned long paddr, void *iip, unsigned long ipsr) spin_unlock(&mca_bh_lock); /* This process is about to be killed itself */ - do_exit(SIGKILL); + make_task_dead(SIGKILL); } /** diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c index e13cb905930fb..753642366e12e 100644 --- a/arch/ia64/kernel/traps.c +++ b/arch/ia64/kernel/traps.c @@ -85,7 +85,7 @@ die (const char *str, struct pt_regs *regs, long err) if (panic_on_oops) panic("Fatal exception"); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); return 0; } diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index c2f299fe9e04a..7f8c49579a2c2 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -272,7 +272,7 @@ retry: regs = NULL; bust_spinlocks(0); if (regs) - do_exit(SIGKILL); + make_task_dead(SIGKILL); return; out_of_memory: diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 344f93d36a9a0..a245c1933d418 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1139,7 +1139,7 @@ void die_if_kernel (char *str, struct pt_regs *fp, int nr) pr_crit("%s: %08x\n", str, nr); show_registers(fp); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } asmlinkage void set_esp0(unsigned long ssp) diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index e9b1d7585b43b..03ebb67b413ef 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -48,7 +48,7 @@ int send_fault_sig(struct pt_regs *regs) pr_alert("Unable to handle kernel access"); pr_cont(" at virtual address %p\n", addr); die_if_kernel("Oops", regs, 0 /*error_code*/); - do_exit(SIGKILL); + make_task_dead(SIGKILL); } return 1; diff --git a/arch/microblaze/kernel/exceptions.c b/arch/microblaze/kernel/exceptions.c index cf99c411503e3..6d3a6a6442205 100644 --- a/arch/microblaze/kernel/exceptions.c +++ b/arch/microblaze/kernel/exceptions.c @@ -44,10 +44,10 @@ void die(const char *str, struct pt_regs *fp, long err) pr_warn("Oops: %s, sig: %ld\n", str, err); show_regs(fp); spin_unlock_irq(&die_lock); - /* do_exit() should take care of panic'ing from an interrupt + /* make_task_dead() should take care of panic'ing from an interrupt * context so we don't handle it here */ - do_exit(err); + make_task_dead(err); } /* for user application debugging */ diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 749089c25d5e6..5a491eca456fc 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -415,7 +415,7 @@ void __noreturn die(const char *str, struct pt_regs *regs) if (regs && kexec_should_crash(current)) crash_kexec(regs); - do_exit(sig); + make_task_dead(sig); } extern struct exception_table_entry __start___dbe_table[]; diff --git a/arch/nds32/kernel/fpu.c b/arch/nds32/kernel/fpu.c index 62bdafbc53f4c..26c62d5a55c15 100644 --- a/arch/nds32/kernel/fpu.c +++ b/arch/nds32/kernel/fpu.c @@ -223,7 +223,7 @@ inline void handle_fpu_exception(struct pt_regs *regs) } } else if (fpcsr & FPCSR_mskRIT) { if (!user_mode(regs)) - do_exit(SIGILL); + make_task_dead(SIGILL); si_signo = SIGILL; } diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c index f4d386b526227..f6648845aae76 100644 --- a/arch/nds32/kernel/traps.c +++ b/arch/nds32/kernel/traps.c @@ -184,7 +184,7 @@ void die(const char *str, struct pt_regs *regs, int err) bust_spinlocks(0); spin_unlock_irq(&die_lock); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } EXPORT_SYMBOL(die); @@ -288,7 +288,7 @@ void unhandled_interruption(struct pt_regs *regs) pr_emerg("unhandled_interruption\n"); show_regs(regs); if (!user_mode(regs)) - do_exit(SIGKILL); + make_task_dead(SIGKILL); force_sig(SIGKILL); } @@ -299,7 +299,7 @@ void unhandled_exceptions(unsigned long entry, unsigned long addr, addr, type); show_regs(regs); if (!user_mode(regs)) - do_exit(SIGKILL); + make_task_dead(SIGKILL); force_sig(SIGKILL); } @@ -326,7 +326,7 @@ void do_revinsn(struct pt_regs *regs) pr_emerg("Reserved Instruction\n"); show_regs(regs); if (!user_mode(regs)) - do_exit(SIGILL); + make_task_dead(SIGILL); force_sig(SIGILL); } diff --git a/arch/nios2/kernel/traps.c b/arch/nios2/kernel/traps.c index 486db793923c0..8e192d6564261 100644 --- a/arch/nios2/kernel/traps.c +++ b/arch/nios2/kernel/traps.c @@ -37,10 +37,10 @@ void die(const char *str, struct pt_regs *regs, long err) show_regs(regs); spin_unlock_irq(&die_lock); /* - * do_exit() should take care of panic'ing from an interrupt + * make_task_dead() should take care of panic'ing from an interrupt * context so we don't handle it here */ - do_exit(err); + make_task_dead(err); } void _exception(int signo, struct pt_regs *regs, int code, unsigned long addr) diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index 932a8ec2b520e..2804852a55924 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -218,7 +218,7 @@ void die(const char *str, struct pt_regs *regs, long err) __asm__ __volatile__("l.nop 1"); do {} while (1); #endif - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } /* This is normally the 'Oops' routine */ diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index 2a1060d747a5d..37988f7f3abcb 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -268,7 +268,7 @@ void die_if_kernel(char *str, struct pt_regs *regs, long err) panic("Fatal exception"); oops_exit(); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } /* gdb uses break 4,8 */ diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index ecfa460f66d17..70b99246dec46 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -246,7 +246,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, if (panic_on_oops) panic("Fatal exception"); - do_exit(signr); + make_task_dead(signr); } NOKPROBE_SYMBOL(oops_end); diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index ae462037910be..c28d4debf5926 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -57,7 +57,7 @@ void die(struct pt_regs *regs, const char *str) if (panic_on_oops) panic("Fatal exception"); if (ret != NOTIFY_STOP) - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr) diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 247b8c859c448..1cfce62caa119 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -189,7 +189,7 @@ no_context: (addr < PAGE_SIZE) ? "NULL pointer dereference" : "paging request", addr); die(regs, "Oops"); - do_exit(SIGKILL); + make_task_dead(SIGKILL); /* * We ran out of memory, call the OOM killer, and return the userspace diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index 34bdc60c0b11d..2100833adfb69 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -210,5 +210,5 @@ void die(struct pt_regs *regs, const char *str) if (panic_on_oops) panic("Fatal exception: panic_on_oops"); oops_exit(); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 0a487fae763ee..d8951274658bd 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -179,7 +179,7 @@ void s390_handle_mcck(void) "malfunction (code 0x%016lx).\n", mcck.mcck_code); printk(KERN_EMERG "mcck: task: %s, pid: %d.\n", current->comm, current->pid); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } } EXPORT_SYMBOL_GPL(s390_handle_mcck); diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 63cf17bc760da..6a228c00b73f4 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -57,7 +57,7 @@ void die(const char *str, struct pt_regs *regs, long err) if (panic_on_oops) panic("Fatal exception"); - do_exit(SIGSEGV); + make_task_dead(SIGSEGV); } void die_if_kernel(const char *str, struct pt_regs *regs, long err) diff --git a/arch/sparc/kernel/traps_32.c b/arch/sparc/kernel/traps_32.c index 4ceecad556a9f..dbf068ac54ff3 100644 --- a/arch/sparc/kernel/traps_32.c +++ b/arch/sparc/kernel/traps_32.c @@ -86,9 +86,7 @@ void __noreturn die_if_kernel(char *str, struct pt_regs *regs) } printk("Instruction DUMP:"); instruction_dump ((unsigned long *) regs->pc); - if(regs->psr & PSR_PS) - do_exit(SIGKILL); - do_exit(SIGSEGV); + make_task_dead((regs->psr & PSR_PS) ? SIGKILL : SIGSEGV); } void do_hw_interrupt(struct pt_regs *regs, unsigned long type) diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index f2b22c496fb97..17768680cbaeb 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -2564,9 +2564,7 @@ void __noreturn die_if_kernel(char *str, struct pt_regs *regs) } if (panic_on_oops) panic("Fatal exception"); - if (regs->tstate & TSTATE_PRIV) - do_exit(SIGKILL); - do_exit(SIGSEGV); + make_task_dead((regs->tstate & TSTATE_PRIV)? SIGKILL : SIGSEGV); } EXPORT_SYMBOL(die_if_kernel); diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 2d837fb54c31b..740df9cc21963 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1659,13 +1659,13 @@ ENTRY(async_page_fault) END(async_page_fault) #endif -ENTRY(rewind_stack_do_exit) +ENTRY(rewind_stack_and_make_dead) /* Prevent any naive code from trying to unwind to our caller. */ xorl %ebp, %ebp movl PER_CPU_VAR(cpu_current_top_of_stack), %esi leal -TOP_OF_KERNEL_STACK_PADDING-PTREGS_SIZE(%esi), %esp - call do_exit + call make_task_dead 1: jmp 1b -END(rewind_stack_do_exit) +END(rewind_stack_and_make_dead) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index c82136030d58f..bd7a4ad0937c4 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1757,7 +1757,7 @@ ENTRY(ignore_sysret) END(ignore_sysret) #endif -ENTRY(rewind_stack_do_exit) +ENTRY(rewind_stack_and_make_dead) UNWIND_HINT_FUNC /* Prevent any naive code from trying to unwind to our caller. */ xorl %ebp, %ebp @@ -1766,5 +1766,5 @@ ENTRY(rewind_stack_do_exit) leaq -PTREGS_SIZE(%rax), %rsp UNWIND_HINT_REGS - call do_exit -END(rewind_stack_do_exit) + call make_task_dead +END(rewind_stack_and_make_dead) diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index e07424e19274b..e72042dc9487c 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -326,7 +326,7 @@ unsigned long oops_begin(void) } NOKPROBE_SYMBOL(oops_begin); -void __noreturn rewind_stack_do_exit(int signr); +void __noreturn rewind_stack_and_make_dead(int signr); void oops_end(unsigned long flags, struct pt_regs *regs, int signr) { @@ -361,7 +361,7 @@ void oops_end(unsigned long flags, struct pt_regs *regs, int signr) * reuse the task stack and that existing poisons are invalid. */ kasan_unpoison_task_stack(current); - rewind_stack_do_exit(signr); + rewind_stack_and_make_dead(signr); } NOKPROBE_SYMBOL(oops_end); diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index 4a6c495ce9b6d..16af8e514cb3b 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -543,5 +543,5 @@ void die(const char * str, struct pt_regs * regs, long err) if (panic_on_oops) panic("Fatal exception"); - do_exit(err); + make_task_dead(err); } diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 36f3011ab6013..6f33a07858cf6 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -51,6 +51,7 @@ extern int sched_fork(unsigned long clone_flags, struct task_struct *p); extern void sched_dead(struct task_struct *p); void __noreturn do_task_dead(void); +void __noreturn make_task_dead(int signr); extern void proc_caches_init(void); diff --git a/kernel/exit.c b/kernel/exit.c index ece64771a31f5..6512d82b4d9b0 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -864,6 +864,15 @@ void __noreturn do_exit(long code) } EXPORT_SYMBOL_GPL(do_exit); +void __noreturn make_task_dead(int signr) +{ + /* + * Take the task off the cpu after something catastrophic has + * happened. + */ + do_exit(signr); +} + void complete_and_exit(struct completion *comp, long code) { if (comp) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index ccf5580442d29..14be7d261ae7a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -136,6 +136,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "panic", "do_exit", "do_task_dead", + "make_task_dead", "__module_put_and_exit", "complete_and_exit", "__reiserfs_panic", @@ -143,7 +144,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, "fortify_panic", "usercopy_abort", "machine_real_restart", - "rewind_stack_do_exit", + "rewind_stack_and_make_dead" "cpu_bringup_and_idle", };