From: Amanieu d'Antras <amanieu@gmail.com> To: unlisted-recipients:; (no To-header on input) Cc: Amanieu d'Antras <amanieu@gmail.com>, Ryan Houdek <Houdek.Ryan@fex-emu.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Steven Price <steven.price@arm.com>, Arnd Bergmann <arnd@kernel.org>, David Laight <David.Laight@aculab.com>, Mark Brown <broonie@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v4 3/8] mm: Support mmap_compat_base with the generic layout Date: Tue, 18 May 2021 10:06:53 +0100 [thread overview] Message-ID: <20210518090658.9519-4-amanieu@gmail.com> (raw) In-Reply-To: <20210518090658.9519-1-amanieu@gmail.com> This enables architectures using the generic mmap layout to support 32-bit mmap calls from 64-bit processes and vice-versa. Architectures using this must define separate 32-bit and 64-bit versions of STACK_TOP, TASK_UNMAPPED_BASE and STACK_RND_MASK. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Co-developed-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> Signed-off-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> --- mm/util.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 8 deletions(-) diff --git a/mm/util.c b/mm/util.c index 54870226cea6..37bd764174b5 100644 --- a/mm/util.c +++ b/mm/util.c @@ -353,12 +353,12 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) return randomize_page(mm->brk, SZ_1G); } -unsigned long arch_mmap_rnd(void) +static unsigned long mmap_rnd(bool compat) { unsigned long rnd; #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS - if (is_compat_task()) + if (compat) rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); else #endif /* CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS */ @@ -367,6 +367,11 @@ unsigned long arch_mmap_rnd(void) return rnd << PAGE_SHIFT; } +unsigned long arch_mmap_rnd(void) +{ + return mmap_rnd(is_compat_task()); +} + static int mmap_is_legacy(struct rlimit *rlim_stack) { if (current->personality & ADDR_COMPAT_LAYOUT) @@ -383,16 +388,17 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) * the face of randomisation. */ #define MIN_GAP (SZ_128M) -#define MAX_GAP (STACK_TOP / 6 * 5) +#define MAX_GAP (stack_top / 6 * 5) -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) +static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack, + unsigned long stack_top, unsigned long stack_rnd_mask) { unsigned long gap = rlim_stack->rlim_cur; unsigned long pad = stack_guard_gap; /* Account for stack randomization if necessary */ if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); + pad += (stack_rnd_mask << PAGE_SHIFT); /* Values close to RLIM_INFINITY can overflow. */ if (gap + pad > gap) @@ -403,21 +409,45 @@ static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(STACK_TOP - gap - rnd); + return PAGE_ALIGN(stack_top - gap - rnd); } void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { unsigned long random_factor = 0UL; +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + unsigned long compat_random_factor = 0UL; +#endif - if (current->flags & PF_RANDOMIZE) + if (current->flags & PF_RANDOMIZE) { +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + random_factor = mmap_rnd(false); + compat_random_factor = mmap_rnd(true); +#else random_factor = arch_mmap_rnd(); +#endif + } if (mmap_is_legacy(rlim_stack)) { +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + mm->mmap_base = TASK_UNMAPPED_BASE_64 + random_factor; + mm->mmap_compat_base = + TASK_UNMAPPED_BASE_32 + compat_random_factor; +#else mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; +#endif mm->get_unmapped_area = arch_get_unmapped_area; } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + mm->mmap_base = mmap_base(random_factor, rlim_stack, + STACK_TOP_64, STACK_RND_MASK_64); + mm->mmap_compat_base = mmap_base(compat_random_factor, + rlim_stack, STACK_TOP_32, + STACK_RND_MASK_32); +#else + mm->mmap_base = mmap_base(random_factor, rlim_stack, STACK_TOP, + STACK_RND_MASK); +#endif mm->get_unmapped_area = arch_get_unmapped_area_topdown; } } -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Amanieu d'Antras <amanieu@gmail.com> Cc: Amanieu d'Antras <amanieu@gmail.com>, Ryan Houdek <Houdek.Ryan@fex-emu.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Steven Price <steven.price@arm.com>, Arnd Bergmann <arnd@kernel.org>, David Laight <David.Laight@aculab.com>, Mark Brown <broonie@kernel.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v4 3/8] mm: Support mmap_compat_base with the generic layout Date: Tue, 18 May 2021 10:06:53 +0100 [thread overview] Message-ID: <20210518090658.9519-4-amanieu@gmail.com> (raw) In-Reply-To: <20210518090658.9519-1-amanieu@gmail.com> This enables architectures using the generic mmap layout to support 32-bit mmap calls from 64-bit processes and vice-versa. Architectures using this must define separate 32-bit and 64-bit versions of STACK_TOP, TASK_UNMAPPED_BASE and STACK_RND_MASK. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Co-developed-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> Signed-off-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> --- mm/util.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 8 deletions(-) diff --git a/mm/util.c b/mm/util.c index 54870226cea6..37bd764174b5 100644 --- a/mm/util.c +++ b/mm/util.c @@ -353,12 +353,12 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) return randomize_page(mm->brk, SZ_1G); } -unsigned long arch_mmap_rnd(void) +static unsigned long mmap_rnd(bool compat) { unsigned long rnd; #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS - if (is_compat_task()) + if (compat) rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); else #endif /* CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS */ @@ -367,6 +367,11 @@ unsigned long arch_mmap_rnd(void) return rnd << PAGE_SHIFT; } +unsigned long arch_mmap_rnd(void) +{ + return mmap_rnd(is_compat_task()); +} + static int mmap_is_legacy(struct rlimit *rlim_stack) { if (current->personality & ADDR_COMPAT_LAYOUT) @@ -383,16 +388,17 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) * the face of randomisation. */ #define MIN_GAP (SZ_128M) -#define MAX_GAP (STACK_TOP / 6 * 5) +#define MAX_GAP (stack_top / 6 * 5) -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) +static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack, + unsigned long stack_top, unsigned long stack_rnd_mask) { unsigned long gap = rlim_stack->rlim_cur; unsigned long pad = stack_guard_gap; /* Account for stack randomization if necessary */ if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); + pad += (stack_rnd_mask << PAGE_SHIFT); /* Values close to RLIM_INFINITY can overflow. */ if (gap + pad > gap) @@ -403,21 +409,45 @@ static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(STACK_TOP - gap - rnd); + return PAGE_ALIGN(stack_top - gap - rnd); } void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { unsigned long random_factor = 0UL; +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + unsigned long compat_random_factor = 0UL; +#endif - if (current->flags & PF_RANDOMIZE) + if (current->flags & PF_RANDOMIZE) { +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + random_factor = mmap_rnd(false); + compat_random_factor = mmap_rnd(true); +#else random_factor = arch_mmap_rnd(); +#endif + } if (mmap_is_legacy(rlim_stack)) { +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + mm->mmap_base = TASK_UNMAPPED_BASE_64 + random_factor; + mm->mmap_compat_base = + TASK_UNMAPPED_BASE_32 + compat_random_factor; +#else mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; +#endif mm->get_unmapped_area = arch_get_unmapped_area; } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); +#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES + mm->mmap_base = mmap_base(random_factor, rlim_stack, + STACK_TOP_64, STACK_RND_MASK_64); + mm->mmap_compat_base = mmap_base(compat_random_factor, + rlim_stack, STACK_TOP_32, + STACK_RND_MASK_32); +#else + mm->mmap_base = mmap_base(random_factor, rlim_stack, STACK_TOP, + STACK_RND_MASK); +#endif mm->get_unmapped_area = arch_get_unmapped_area_topdown; } } -- 2.31.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-18 9:07 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-18 9:06 [RESEND PATCH v4 0/8] arm64: Allow 64-bit tasks to invoke compat syscalls Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 1/8] mm: Add arch_get_mmap_base_topdown macro Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 2/8] hugetlbfs: Use arch_get_mmap_* macros Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras [this message] 2021-05-18 9:06 ` [RESEND PATCH v4 3/8] mm: Support mmap_compat_base with the generic layout Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 4/8] arm64: Separate in_compat_syscall from is_compat_task Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 5/8] arm64: mm: Use HAVE_ARCH_COMPAT_MMAP_BASES Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 6/8] arm64: Add a compat syscall flag to thread_info Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 7/8] arm64: Forbid calling compat sigreturn from 64-bit tasks Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 9:06 ` [RESEND PATCH v4 8/8] arm64: Allow 64-bit tasks to invoke compat syscalls Amanieu d'Antras 2021-05-18 9:06 ` Amanieu d'Antras 2021-05-18 13:02 ` Arnd Bergmann 2021-05-18 13:02 ` Arnd Bergmann 2021-05-18 20:26 ` David Laight 2021-05-18 20:26 ` David Laight 2021-05-18 22:41 ` Ryan Houdek 2021-05-18 22:41 ` Ryan Houdek 2021-05-18 23:51 ` Amanieu d'Antras 2021-05-18 23:51 ` Amanieu d'Antras 2021-05-19 15:30 ` Steven Price 2021-05-19 15:30 ` Steven Price 2021-05-19 16:14 ` Amanieu d'Antras 2021-05-19 16:14 ` Amanieu d'Antras 2021-05-21 8:51 ` Steven Price 2021-05-21 8:51 ` Steven Price 2021-05-21 19:18 ` Amanieu d'Antras 2021-05-21 19:18 ` Amanieu d'Antras 2021-05-24 11:20 ` Steven Price 2021-05-24 11:20 ` Steven Price 2021-05-24 12:38 ` David Laight 2021-05-24 12:38 ` David Laight 2021-05-18 23:52 ` Ryan Houdek 2021-05-18 23:52 ` Ryan Houdek
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