| Message ID | 20220601143114.133524-1-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | powerpc/kasan: Force thread size increase with KASAN | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 23 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 7 jobs. |
Le 01/06/2022 à 16:31, Michael Ellerman a écrit : > KASAN causes increased stack usage, which can lead to stack overflows. > > The logic in Kconfig to suggest a larger default doesn't work if a user > has CONFIG_EXPERT enabled and has an existing .config with a smaller > value. > > Follow the lead of x86 and arm64, and force the thread size to be > increased when KASAN is enabled. > > That also has the effect of enlarging the stack for 64-bit KASAN builds, > which is also desirable. > > Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT") > Reported-by: Erhard Furtner <erhard_f@mailbox.org> > Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> > --- > arch/powerpc/Kconfig | 1 - > arch/powerpc/include/asm/thread_info.h | 9 +++++++-- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 54dbbb1d4b36..b1760d615bb7 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -790,7 +790,6 @@ config THREAD_SHIFT > range 13 15 > default "15" if PPC_256K_PAGES > default "14" if PPC64 > - default "14" if KASAN > default "13" > help > Used to define the stack size. The default is almost always what you > diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h > index 125328d1b980..c9735f93f8e6 100644 > --- a/arch/powerpc/include/asm/thread_info.h > +++ b/arch/powerpc/include/asm/thread_info.h > @@ -14,12 +14,17 @@ > > #ifdef __KERNEL__ > > -#if defined(CONFIG_VMAP_STACK) && CONFIG_THREAD_SHIFT < PAGE_SHIFT > -#define THREAD_SHIFT PAGE_SHIFT > +#ifdef CONFIG_KASAN > +#define THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1) > #else > #define THREAD_SHIFT CONFIG_THREAD_SHIFT > #endif > > +#if defined(CONFIG_VMAP_STACK) && THREAD_SHIFT < PAGE_SHIFT > +#undef THREAD_SHIFT I dislike this undef. I would was done #ifdef CONFIG_KASAN #define MIN_THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1) #else #define MIN_THREAD_SHIFT CONFIG_THREAD_SHIFT #endif #if defined(CONFIG_VMAP_STACK) && MIN_THREAD_SHIFT < PAGE_SHIFT #define THREAD_SHIFT PAGE_SHIFT #else #define THREAD_SHIFT MIN_THREAD_SHIFT #endif > +#define THREAD_SHIFT PAGE_SHIFT > +#endif > + > #define THREAD_SIZE (1 << THREAD_SHIFT) > > /*
On Thu, 2 Jun 2022 00:31:14 +1000, Michael Ellerman wrote: > KASAN causes increased stack usage, which can lead to stack overflows. > > The logic in Kconfig to suggest a larger default doesn't work if a user > has CONFIG_EXPERT enabled and has an existing .config with a smaller > value. > > Follow the lead of x86 and arm64, and force the thread size to be > increased when KASAN is enabled. > > [...] Applied to powerpc/fixes. [1/1] powerpc/kasan: Force thread size increase with KASAN https://git.kernel.org/powerpc/c/3e8635fb2e072672cbc650989ffedf8300ad67fb cheers
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 54dbbb1d4b36..b1760d615bb7 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -790,7 +790,6 @@ config THREAD_SHIFT range 13 15 default "15" if PPC_256K_PAGES default "14" if PPC64 - default "14" if KASAN default "13" help Used to define the stack size. The default is almost always what you diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 125328d1b980..c9735f93f8e6 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -14,12 +14,17 @@ #ifdef __KERNEL__ -#if defined(CONFIG_VMAP_STACK) && CONFIG_THREAD_SHIFT < PAGE_SHIFT -#define THREAD_SHIFT PAGE_SHIFT +#ifdef CONFIG_KASAN +#define THREAD_SHIFT (CONFIG_THREAD_SHIFT + 1) #else #define THREAD_SHIFT CONFIG_THREAD_SHIFT #endif +#if defined(CONFIG_VMAP_STACK) && THREAD_SHIFT < PAGE_SHIFT +#undef THREAD_SHIFT +#define THREAD_SHIFT PAGE_SHIFT +#endif + #define THREAD_SIZE (1 << THREAD_SHIFT) /*
KASAN causes increased stack usage, which can lead to stack overflows. The logic in Kconfig to suggest a larger default doesn't work if a user has CONFIG_EXPERT enabled and has an existing .config with a smaller value. Follow the lead of x86 and arm64, and force the thread size to be increased when KASAN is enabled. That also has the effect of enlarging the stack for 64-bit KASAN builds, which is also desirable. Fixes: edbadaf06710 ("powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT") Reported-by: Erhard Furtner <erhard_f@mailbox.org> Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/Kconfig | 1 - arch/powerpc/include/asm/thread_info.h | 9 +++++++-- 2 files changed, 7 insertions(+), 3 deletions(-)