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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-17 10:06:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-17 10:06:21 +0100 |
| commit | 3953831982eb9c90506c4a2e8d7e6c3d840abf8a (patch) | |
| tree | cffca6730505cb5426f61e5c6f3fe36e1e90288b /drivers/misc | |
| parent | af40d16042d674442db8cf5fd654fabcd45fea44 (diff) | |
| parent | 90091c367e74d5b58d9ebe979cc363f7468f58d3 (diff) | |
| download | linux-3953831982eb9c90506c4a2e8d7e6c3d840abf8a.tar.gz linux-3953831982eb9c90506c4a2e8d7e6c3d840abf8a.tar.bz2 linux-3953831982eb9c90506c4a2e8d7e6c3d840abf8a.zip | |
Merge tag 'lkdtm-v5.17-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into char-misc-next
Kees writes:
lkdtm updates for v5.17-rc1
- Fix printk() usage during recursion (Ard Biesheuvel)
- Fix rodata section to actually have contents (Christophe Leroy)
- Add notes about lkdtm_kernel_info usage (Kees Cook)
- Avoid stack-entropy selftest when LKDTM is disabled (Misono Tomohiro)
* tag 'lkdtm-v5.17-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
selftest/lkdtm: Skip stack-entropy test if lkdtm is not available
lkdtm: Fix content of section containing lkdtm_rodata_do_nothing()
lkdtm: avoid printk() in recursive_loop()
lkdtm: Note that lkdtm_kernel_info should be removed in the future
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/lkdtm/Makefile | 2 | ||||
| -rw-r--r-- | drivers/misc/lkdtm/bugs.c | 16 | ||||
| -rw-r--r-- | drivers/misc/lkdtm/core.c | 6 |
3 files changed, 15 insertions, 9 deletions
diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile index aa12097668d3..e2984ce51fe4 100644 --- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -20,7 +20,7 @@ CFLAGS_REMOVE_rodata.o += $(CC_FLAGS_LTO) OBJCOPYFLAGS := OBJCOPYFLAGS_rodata_objcopy.o := \ - --rename-section .noinstr.text=.rodata,alloc,readonly,load + --rename-section .noinstr.text=.rodata,alloc,readonly,load,contents targets += rodata.o rodata_objcopy.o $(obj)/rodata_objcopy.o: $(obj)/rodata.o FORCE $(call if_changed,objcopy) diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index f4cb94a9aa9c..f21854ac5cc2 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -41,20 +41,22 @@ static DEFINE_SPINLOCK(lock_me_up); * Make sure compiler does not optimize this function or stack frame away: * - function marked noinline * - stack variables are marked volatile - * - stack variables are written (memset()) and read (pr_info()) - * - function has external effects (pr_info()) - * */ + * - stack variables are written (memset()) and read (buf[..] passed as arg) + * - function may have external effects (memzero_explicit()) + * - no tail recursion possible + */ static int noinline recursive_loop(int remaining) { volatile char buf[REC_STACK_SIZE]; + volatile int ret; memset((void *)buf, remaining & 0xFF, sizeof(buf)); - pr_info("loop %d/%d ...\n", (int)buf[remaining % sizeof(buf)], - recur_count); if (!remaining) - return 0; + ret = 0; else - return recursive_loop(remaining - 1); + ret = recursive_loop((int)buf[remaining % sizeof(buf)] - 1); + memzero_explicit((void *)buf, sizeof(buf)); + return ret; } /* If the depth is negative, use the default, otherwise keep parameter. */ diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 609d9ee2acc0..d4c6cdced37b 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -212,7 +212,11 @@ module_param(cpoint_count, int, 0644); MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\ "crash point is to be hit to trigger action"); -/* For test debug reporting. */ +/* + * For test debug reporting when CI systems provide terse summaries. + * TODO: Remove this once reasonable reporting exists in most CI systems: + * https://lore.kernel.org/lkml/CAHk-=wiFvfkoFixTapvvyPMN9pq5G-+Dys2eSyBa1vzDGAO5+A@mail.gmail.com + */ char *lkdtm_kernel_info; /* Return the crashtype number or NULL if the name is invalid */ |