diff options
| author |   Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-10-19 09:29:30 +0200 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2021-12-09 22:41:20 +1100 |
| commit | fcf9bb6d32f8a268bc3daf3281e3beefabec4e7c (patch) | |
| tree | 65270cd8f92d4809d2e073cb07da6897ce55bcd8 | |
| parent | powerpc/kuap: Wire-up KUAP on 44x (diff) | |
| download | linux-dev-fcf9bb6d32f8a268bc3daf3281e3beefabec4e7c.tar.xz linux-dev-fcf9bb6d32f8a268bc3daf3281e3beefabec4e7c.zip | |
powerpc/kuap: Wire-up KUAP on 40x
This adds KUAP support to 40x. This is done by checking
the content of SPRN_PID at the time user pgtable is loaded.
40x doesn't have KUEP, but KUAP implies KUEP because when the
PID doesn't match the page's PID, the page cannot be read nor
executed.
So KUEP is now automatically selected when KUAP is selected and
disabled when KUAP is disabled.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aaefa91897ddc42ac11019dc0e1d1a525bd08e90.1634627931.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/kernel/head_40x.S | 8 | ||||
| -rw-r--r-- | arch/powerpc/mm/nohash/kup.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/Kconfig.cputype | 7 |
3 files changed, 15 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index e783860bea83..b6c6d1de5fd5 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -298,6 +298,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) 3: mfspr r11,SPRN_SPRG_THREAD lwz r11,PGDIR(r11) +#ifdef CONFIG_PPC_KUAP + rlwinm. r9, r9, 0, 0xff + beq 5f /* Kuap fault */ +#endif 4: tophys(r11, r11) rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ @@ -378,6 +382,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) 3: mfspr r11,SPRN_SPRG_THREAD lwz r11,PGDIR(r11) +#ifdef CONFIG_PPC_KUAP + rlwinm. r9, r9, 0, 0xff + beq 5f /* Kuap fault */ +#endif 4: tophys(r11, r11) rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c index eaea52231dd6..552becf90e97 100644 --- a/arch/powerpc/mm/nohash/kup.c +++ b/arch/powerpc/mm/nohash/kup.c @@ -19,6 +19,8 @@ EXPORT_SYMBOL(disable_kuap_key); void setup_kuap(bool disabled) { if (disabled) { + if (IS_ENABLED(CONFIG_40x)) + disable_kuep = true; if (smp_processor_id() == boot_cpuid) static_branch_enable(&disable_kuap_key); return; diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 3f00e75edf70..95e034e061c2 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -54,6 +54,9 @@ config 40x select PPC_UDBG_16550 select 4xx_SOC select HAVE_PCI + select PPC_HAVE_KUAP + select PPC_HAVE_KUEP + select PPC_KUEP if PPC_KUAP config 44x bool "AMCC 44x, 46x or 47x" @@ -425,9 +428,9 @@ config PPC_HAVE_KUEP bool config PPC_KUEP - bool "Kernel Userspace Execution Prevention" + bool "Kernel Userspace Execution Prevention" if !40x depends on PPC_HAVE_KUEP - default y + default y if !40x help Enable support for Kernel Userspace Execution Prevention (KUEP) |