diff options
| author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2024-09-17 17:03:28 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-10-01 13:08:11 -0700 |
| commit | cfb10de18538e383dbc4f3ce7f477ce49287ff3d (patch) | |
| tree | 3ea0cffff996f84aaa0af066035102b9665fb344 /arch | |
| parent | c625154993d0d24a962b1830cd5ed92adda2cf86 (diff) | |
riscv: Fix kernel stack size when KASAN is enabled
We use Kconfig to select the kernel stack size, doubling the default
size if KASAN is enabled.
But that actually only works if KASAN is selected from the beginning,
meaning that if KASAN config is added later (for example using
menuconfig), CONFIG_THREAD_SIZE_ORDER won't be updated, keeping the
default size, which is not enough for KASAN as reported in [1].
So fix this by moving the logic to compute the right kernel stack into a
header.
Fixes: a7555f6b62e7 ("riscv: stack: Add config of thread stack size")
Reported-by: syzbot+ba9eac24453387a9d502@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000eb301906222aadc2@google.com/ [1]
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240917150328.59831-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/Kconfig | 3 | ||||
| -rw-r--r-- | arch/riscv/include/asm/thread_info.h | 7 |
2 files changed, 7 insertions, 3 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 22dc5ea4196c..62545946ecf4 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -777,8 +777,7 @@ config IRQ_STACKS config THREAD_SIZE_ORDER int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT range 0 4 - default 1 if 32BIT && !KASAN - default 3 if 64BIT && KASAN + default 1 if 32BIT default 2 help Specify the Pages of thread stack size (from 4KB to 64KB), which also diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index ebe52f96da34..9c10fb180f43 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -13,7 +13,12 @@ #include <linux/sizes.h> /* thread information allocation */ -#define THREAD_SIZE_ORDER CONFIG_THREAD_SIZE_ORDER +#ifdef CONFIG_KASAN +#define KASAN_STACK_ORDER 1 +#else +#define KASAN_STACK_ORDER 0 +#endif +#define THREAD_SIZE_ORDER (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER) #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) /* |