kernel/drivers/s390/char/sclp.c, branch linux-6.9.y

s390/sclp: Fix sclp_init() cleanup on failure

2024-07-25T07:53:34Z

[ Upstream commit 6434b33faaa063df500af355ee6c3942e0f8d982 ] If sclp_init() fails it only partially cleans up: if there are multiple failing calls to sclp_init() sclp_state_change_event will be added several times to sclp_reg_list, which results in the following warning: ------------[ cut here ]------------ list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10. WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3 Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 ... Call Trace: [<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8 ([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8) [<000003ffe0a8d37e>] sclp_init+0x40e/0x450 [<000003ffe00009f2>] do_one_initcall+0x42/0x1e0 [<000003ffe15b77a6>] do_initcalls+0x126/0x150 [<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8 [<000003ffe0d6650e>] kernel_init+0x2e/0x180 [<000003ffe000301c>] __ret_from_fork+0x3c/0x60 [<000003ffe0d759ca>] ret_from_fork+0xa/0x30 Fix this by removing sclp_state_change_event from sclp_reg_list when sclp_init() fails. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/sclp: replace deprecated strncpy with strtomem

2023-10-25T13:08:30Z

Let's move away from using strncpy() as it is deprecated [1]. Instead use strtomem() as `e.id` is already marked as nonstring: | char id[4] __nonstring; We don't need strtomem_pad() because `e` is already memset to 0 -- rendering any additional NUL-padding useless. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-char-sclp-c-v1-1-eaeef80522bb@google.com Signed-off-by: Vasily Gorbik

s390/ctlreg: add struct ctlreg

2023-09-19T11:26:56Z

Add struct ctlreg to enforce strict type checking / usage for control register functions. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ctlreg: use local_ctl_load() and local_ctl_store() where possible

2023-09-19T11:26:56Z

Convert all single control register usages of __local_ctl_load() and __local_ctl_store() to local_ctl_load() and local_ctl_store(). This also requires to change the type of some struct lowcore members from __u64 to unsigned long. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ctlreg: add local and system prefix to some functions

2023-09-19T11:26:56Z

Add local and system prefix to some functions to clarify they change control register contents on either the local CPU or the on all CPUs. This results in the following API: Two defines which load and save multiple control registers. The defines correlate with the following C prototypes: void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high); void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high); Two functions which locally set or clear one bit for a specified control register: void local_ctl_set_bit(unsigned int cr, unsigned int bit); void local_ctl_clear_bit(unsigned int cr, unsigned int bit); Two functions which set or clear one bit for a specified control register on all CPUs: void system_ctl_set_bit(unsigned int cr, unsigned int bit); void system_ctl_clear_bit(unsigend int cr, unsigned int bit); Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/sclp: allow to change sclp_console_drop during runtime

2022-11-29T13:17:04Z

Make sclp's con_drop sysfs attribute also writable, and allow to change its value during runtime. This way handling of sclp console drop handling is consistent with the 3215 device driver. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/sclp: convert to use sysfs_emit()

2022-11-29T13:17:04Z

Use sysfs_emit() for all sclp sysfs show functions, which is the current standard way to generate output strings. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/sclp: use kstrobool() to parse sclp_con_drop parameter

2022-11-29T13:17:03Z

Use kstrobool() to parse sclp_con_drop parameter. This way handling of valid values for the sclp_con_drop parameter is identical to the con3215_drop parameter. In particular this allows to pass values like "yes" and "true", which was not possible before. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/sclp: Fix typo in comments

2022-06-30T17:40:36Z

Remove the repeated word 'and' from comments Signed-off-by: Jiang Jian Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20220622142713.14187-1-jiangjian@cdjrlc.com Signed-off-by: Alexander Gordeev

s390: cleanup timer API use

2022-03-27T20:18:39Z

cleanup the s390's use of the timer API - del_timer() contains timer_pending() condition - mod_timer(timer, expires) is equivalent to: del_timer(timer); timer->expires = expires; add_timer(timer); If the timer is inactive it will be activated, using add_timer() on condition !timer_pending(&private->timer) is redundant. Just cleanup, no logic change. Signed-off-by: Yu Liao Link: https://lore.kernel.org/r/20220322030057.1243196-1-liaoyu15@huawei.com Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik