diff options
| author | Will Deacon <will@kernel.org> | 2021-03-18 17:07:38 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-03-24 16:48:41 +0000 |
| commit | 6e554abd07002405fd9175284a10729e2f54be43 (patch) | |
| tree | 4392154bd6953ef5bf06e2fcc93b55acb5d09b0d /arch | |
| parent | 77ec462536a13d4b428a1eead725c4818a49f0b1 (diff) | |
arm64: compat: Poison the compat sigpage
Commit 9c698bff66ab ("ARM: ensure the signal page contains defined contents")
poisoned the unused portions of the signal page for 32-bit Arm.
Implement the same poisoning for the compat signal page on arm64 rather
than using __GFP_ZERO.
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20210318170738.7756-6-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/vdso.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 16bf0b46fb70..159b72a646ab 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -318,17 +318,20 @@ static int aarch32_alloc_kuser_vdso_page(void) return 0; } +#define COMPAT_SIGPAGE_POISON_WORD 0xe7fddef1 static int aarch32_alloc_sigpage(void) { extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; - unsigned long sigpage; + __le32 poison = cpu_to_le32(COMPAT_SIGPAGE_POISON_WORD); + void *sigpage; - sigpage = get_zeroed_page(GFP_KERNEL); + sigpage = (void *)__get_free_page(GFP_KERNEL); if (!sigpage) return -ENOMEM; - memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz); + memset32(sigpage, (__force u32)poison, PAGE_SIZE / sizeof(poison)); + memcpy(sigpage, __aarch32_sigret_code_start, sigret_sz); aarch32_sig_page = virt_to_page(sigpage); return 0; } |