arch/riscv/kernel/traps.c:48 die() warn: variable dereferenced before check 'regs' (see line 46)
From: Dan Carpenter
Date: Thu Aug 11 2022 - 06:34:36 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: f41445645ab5d172e6090d00c332c335d8dba337
commit: 3f1901110a89b0e2e13adb2ac8d1a7102879ea98 RISC-V: Add fast call path of crash_kexec()
config: riscv-randconfig-m031-20220810 (https://download.01.org/0day-ci/archive/20220811/202208110538.uaLOQmBs-lkp@xxxxxxxxx/config)
compiler: riscv64-linux-gcc (GCC) 12.1.0
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
smatch warnings:
arch/riscv/kernel/traps.c:48 die() warn: variable dereferenced before check 'regs' (see line 46)
vim +/regs +48 arch/riscv/kernel/traps.c
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 31 void die(struct pt_regs *regs, const char *str)
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 32 {
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 33 static int die_counter;
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 34 int ret;
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 35
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 36 oops_enter();
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 37
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 38 spin_lock_irq(&die_lock);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 39 console_verbose();
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 40 bust_spinlocks(1);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 41
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 42 pr_emerg("%s [#%d]\n", str, ++die_counter);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 43 print_modules();
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 44 show_regs(regs);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 45
a4c3733d32a72f Christoph Hellwig 2019-10-28 @46 ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV);
^^^^^^^^^^^
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 47
3f1901110a89b0 Xianting Tian 2022-06-06 @48 if (regs && kexec_should_crash(current))
^^^^
Delete this NULL check.
3f1901110a89b0 Xianting Tian 2022-06-06 49 crash_kexec(regs);
3f1901110a89b0 Xianting Tian 2022-06-06 50
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 51 bust_spinlocks(0);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 52 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 53 spin_unlock_irq(&die_lock);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 54 oops_exit();
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 55
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 56 if (in_interrupt())
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 57 panic("Fatal exception in interrupt");
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 58 if (panic_on_oops)
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 59 panic("Fatal exception");
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 60 if (ret != NOTIFY_STOP)
0e25498f8cd43c Eric W. Biederman 2021-06-28 61 make_task_dead(SIGSEGV);
76d2a0493a17d4 Palmer Dabbelt 2017-07-10 62 }
--
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