From: Jason A. Donenfeld Date: Tue, 22 Feb 2022 12:46:10 +0000 (+0100) Subject: random: round-robin registers as ulong, not u32 X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e400ba11a241386dc27e57c35c00f61dce92e2f4;p=linux.git random: round-robin registers as ulong, not u32 commit da3951ebdcd1cb1d5c750e08cd05aee7b0c04d9a upstream. When the interrupt handler does not have a valid cycle counter, it calls get_reg() to read a register from the irq stack, in round-robin. Currently it does this assuming that registers are 32-bit. This is _probably_ the case, and probably all platforms without cycle counters are in fact 32-bit platforms. But maybe not, and either way, it's not quite correct. This commit fixes that to deal with `unsigned long` rather than `u32`. Cc: Theodore Ts'o Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/char/random.c b/drivers/char/random.c index 6c36940e2c6ec..35991d87d6199 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1261,15 +1261,15 @@ int random_online_cpu(unsigned int cpu) } #endif -static u32 get_reg(struct fast_pool *f, struct pt_regs *regs) +static unsigned long get_reg(struct fast_pool *f, struct pt_regs *regs) { - u32 *ptr = (u32 *)regs; + unsigned long *ptr = (unsigned long *)regs; unsigned int idx; if (regs == NULL) return 0; idx = READ_ONCE(f->reg_idx); - if (idx >= sizeof(struct pt_regs) / sizeof(u32)) + if (idx >= sizeof(struct pt_regs) / sizeof(unsigned long)) idx = 0; ptr += idx++; WRITE_ONCE(f->reg_idx, idx);