From bdba0051ebcb3c6372f9cc0b2524c47cc6ce46fd Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 7 Jan 2013 16:12:31 +0000 Subject: [PATCH 1/4] arm64: vdso: remove broken, redundant sequence counting for timezones This patch is an arm64 version of ce73ec6db47a ("powerpc/vdso: Remove redundant locking in update_vsyscall_tz()"). Timezone data is not protected, so the sequence counter is not required to ensure consistency. Furthermore, having multiple paths updating the counter leads to a race between update_vsyscall and update_vsyscall_tz, so remove the timezone sequence counting from both the kernel and the vdso. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/vdso.c | 4 ---- arch/arm64/kernel/vdso/gettimeofday.S | 2 -- 2 files changed, 6 deletions(-) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index c958cb84d75f..6a389dc1bd49 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -252,10 +252,6 @@ void update_vsyscall(struct timekeeper *tk) void update_vsyscall_tz(void) { - ++vdso_data->tb_seq_count; - smp_wmb(); vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; vdso_data->tz_dsttime = sys_tz.tz_dsttime; - smp_wmb(); - ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index 8bf658d974f9..f0a6d10b5211 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -73,8 +73,6 @@ ENTRY(__kernel_gettimeofday) /* If tz is NULL, return 0. */ cbz x1, 3f ldp w4, w5, [vdso_data, #VDSO_TZ_MINWEST] - seqcnt_read w9 - seqcnt_check w9, 1b stp w4, w5, [x1, #TZ_MINWEST] 3: mov x0, xzr From 02522463c84748b3b8ad770f9424bcfa70a5b4c4 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 9 Jan 2013 11:08:10 +0000 Subject: [PATCH 2/4] arm64: mm: only wrprotect clean ptes if they are present Marking non-present ptes as read-only can corrupt file ptes, breaking things like swap and file mappings. This patch ensures that we only manipulate user pte bits when the pte is marked present. Cc: Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 64b133949502..7adf4142a85c 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -132,9 +132,8 @@ extern struct page *empty_zero_page; #define pte_write(pte) (!(pte_val(pte) & PTE_RDONLY)) #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) -#define pte_present_exec_user(pte) \ - ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == \ - (PTE_VALID | PTE_USER)) +#define pte_present_user(pte) \ + ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) #define PTE_BIT_FUNC(fn,op) \ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } @@ -157,10 +156,13 @@ extern void __sync_icache_dcache(pte_t pteval, unsigned long addr); static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - if (pte_present_exec_user(pte)) - __sync_icache_dcache(pte, addr); - if (!pte_dirty(pte)) - pte = pte_wrprotect(pte); + if (pte_present_user(pte)) { + if (pte_exec(pte)) + __sync_icache_dcache(pte, addr); + if (!pte_dirty(pte)) + pte = pte_wrprotect(pte); + } + set_pte(ptep, pte); } From a6fadf7e67d3794aae40244f435d281a62736c93 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 18 Dec 2012 14:15:15 +0000 Subject: [PATCH 3/4] arm64: mm: introduce present, faulting entries for PAGE_NONE This is mostly a port of dbf62d50067e ("ARM: mm: introduce L_PTE_VALID for page table entries") and 26ffd0d43b18 ("ARM: mm: introduce present, faulting entries for PAGE_NONE") from ARM, which makes use of present, faulting page table entries for page table entries mapped as PROT_NONE. The main difference with this implementation is that we can make use of the two pte type bits in order to avoid allocating a software bit for identifying PROT_NONE pages, instead reserving the 10b suffix for these types of mappings. This is required to prevent users from accessing such pages via syscalls such as read/write over a pipe. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 7adf4142a85c..e333a243bfcc 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -24,7 +24,8 @@ /* * Software defined PTE bits definition. */ -#define PTE_VALID (_AT(pteval_t, 1) << 0) /* pte_present() check */ +#define PTE_VALID (_AT(pteval_t, 1) << 0) +#define PTE_PROT_NONE (_AT(pteval_t, 1) << 1) /* only when !PTE_VALID */ #define PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !pte_present() */ #define PTE_DIRTY (_AT(pteval_t, 1) << 55) #define PTE_SPECIAL (_AT(pteval_t, 1) << 56) @@ -60,9 +61,12 @@ extern void __pgd_error(const char *file, int line, unsigned long val); extern pgprot_t pgprot_default; -#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) +#define __pgprot_modify(prot,mask,bits) \ + __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) -#define PAGE_NONE _MOD_PROT(pgprot_default, PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) +#define _MOD_PROT(p, b) __pgprot_modify(p, 0, b) + +#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE) #define PAGE_SHARED _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN) #define PAGE_COPY _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) @@ -72,7 +76,7 @@ extern pgprot_t pgprot_default; #define PAGE_KERNEL _MOD_PROT(pgprot_default, PTE_PXN | PTE_UXN | PTE_DIRTY) #define PAGE_KERNEL_EXEC _MOD_PROT(pgprot_default, PTE_UXN | PTE_DIRTY) -#define __PAGE_NONE __pgprot(_PAGE_DEFAULT | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) +#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE) #define __PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define __PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) #define __PAGE_COPY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) @@ -125,14 +129,14 @@ extern struct page *empty_zero_page; /* * The following only work if pte_present(). Undefined behaviour otherwise. */ -#define pte_present(pte) (pte_val(pte) & PTE_VALID) +#define pte_present(pte) (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) #define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY) #define pte_young(pte) (pte_val(pte) & PTE_AF) #define pte_special(pte) (pte_val(pte) & PTE_SPECIAL) #define pte_write(pte) (!(pte_val(pte) & PTE_RDONLY)) #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) -#define pte_present_user(pte) \ +#define pte_valid_user(pte) \ ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) #define PTE_BIT_FUNC(fn,op) \ @@ -156,7 +160,7 @@ extern void __sync_icache_dcache(pte_t pteval, unsigned long addr); static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - if (pte_present_user(pte)) { + if (pte_valid_user(pte)) { if (pte_exec(pte)) __sync_icache_dcache(pte, addr); if (!pte_dirty(pte)) @@ -172,9 +176,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define pte_huge(pte) ((pte_val(pte) & PTE_TYPE_MASK) == PTE_TYPE_HUGEPAGE) #define pte_mkhuge(pte) (__pte((pte_val(pte) & ~PTE_TYPE_MASK) | PTE_TYPE_HUGEPAGE)) -#define __pgprot_modify(prot,mask,bits) \ - __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) - #define __HAVE_ARCH_PTE_SPECIAL /* @@ -266,7 +267,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { - const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY; + const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY | + PTE_PROT_NONE | PTE_VALID; pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); return pte; } From 72d0ac048f3ded4022cf1cc72f54073f6fcad72f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 14 Jan 2013 14:45:46 +0000 Subject: [PATCH 4/4] arm64: compat: add syscall table entries for new syscalls There have been a number of new syscalls introduced to arch/arm/ since the compat layer was implemented for arm64, so add pointers to the relevant functions to the compat syscall table. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/unistd32.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 58432625fdb3..5ef47ba3ed45 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -395,8 +395,13 @@ __SYSCALL(370, sys_name_to_handle_at) __SYSCALL(371, compat_sys_open_by_handle_at) __SYSCALL(372, compat_sys_clock_adjtime) __SYSCALL(373, sys_syncfs) +__SYSCALL(374, compat_sys_sendmmsg) +__SYSCALL(375, sys_setns) +__SYSCALL(376, compat_sys_process_vm_readv) +__SYSCALL(377, compat_sys_process_vm_writev) +__SYSCALL(378, sys_ni_syscall) /* 378 for kcmp */ -#define __NR_compat_syscalls 374 +#define __NR_compat_syscalls 379 /* * Compat syscall numbers used by the AArch64 kernel.