From mboxrd@z Thu Jan 1 00:00:00 1970 From: ynorov@caviumnetworks.com (Yury Norov) Date: Thu, 14 Jan 2016 20:23:09 +0300 Subject: [PATCH v6 12/21] arm64: ptrace: handle ptrace_request differently for aarch32 and ilp32 In-Reply-To: <1452792198-10718-1-git-send-email-ynorov@caviumnetworks.com> References: <1452792198-10718-1-git-send-email-ynorov@caviumnetworks.com> Message-ID: <1452792198-10718-13-git-send-email-ynorov@caviumnetworks.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Here new ptrace syscall handler is introsuced to avoid run-time detection of the task type. Signed-off-by: Yury Norov --- arch/arm64/include/asm/unistd32.h | 2 +- arch/arm64/kernel/ptrace.c | 50 ++++++++++++++++++++++++++++++++++++++- arch/arm64/kernel/sys32.c | 1 + include/linux/ptrace.h | 6 +++++ kernel/ptrace.c | 10 ++++---- 5 files changed, 62 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 5b925b7..f57bbe3 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -74,7 +74,7 @@ __SYSCALL(__NR_getuid, sys_getuid16) /* 25 was sys_stime */ __SYSCALL(25, sys_ni_syscall) #define __NR_ptrace 26 -__SYSCALL(__NR_ptrace, compat_sys_ptrace) +__SYSCALL(__NR_ptrace, compat_sys_aarch32_ptrace) /* 27 was sys_alarm */ __SYSCALL(27, sys_ni_syscall) /* 28 was sys_fstat */ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index c166548..607a140 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -1108,7 +1109,7 @@ static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num, } #endif /* CONFIG_HAVE_HW_BREAKPOINT */ -long compat_arch_ptrace(struct task_struct *child, compat_long_t request, +static long compat_a32_ptrace(struct task_struct *child, compat_long_t request, compat_ulong_t caddr, compat_ulong_t cdata) { unsigned long addr = caddr; @@ -1185,8 +1186,55 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, return ret; } + +COMPAT_SYSCALL_DEFINE4(aarch32_ptrace, compat_long_t, request, compat_long_t, pid, + compat_long_t, addr, compat_long_t, data) +{ + struct task_struct *child; + long ret; + + if (request == PTRACE_TRACEME) { + ret = ptrace_traceme(); + goto out; + } + + child = ptrace_get_task_struct(pid); + if (IS_ERR(child)) { + ret = PTR_ERR(child); + goto out; + } + + if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { + ret = ptrace_attach(child, request, addr, data); + goto out_put_task_struct; + } + + ret = ptrace_check_attach(child, request == PTRACE_KILL || + request == PTRACE_INTERRUPT); + if (!ret) { + ret = compat_a32_ptrace(child, request, addr, data); + if (ret || request != PTRACE_DETACH) + ptrace_unfreeze_traced(child); + } + + out_put_task_struct: + put_task_struct(child); + out: + return ret; +} + #endif /* CONFIG_AARCH32_EL0 */ +#ifdef CONFIG_COMPAT + +long compat_arch_ptrace(struct task_struct *child, compat_long_t request, + compat_ulong_t caddr, compat_ulong_t cdata) +{ + return compat_ptrace_request(child, request, caddr, cdata); +} + +#endif /* CONFIG_COMPAT */ + const struct user_regset_view *task_user_regset_view(struct task_struct *task) { #ifdef CONFIG_AARCH32_EL0 diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c index a40b134..3752443 100644 --- a/arch/arm64/kernel/sys32.c +++ b/arch/arm64/kernel/sys32.c @@ -38,6 +38,7 @@ asmlinkage long compat_sys_fadvise64_64_wrapper(void); asmlinkage long compat_sys_sync_file_range2_wrapper(void); asmlinkage long compat_sys_fallocate_wrapper(void); asmlinkage long compat_sys_mmap2_wrapper(void); +asmlinkage long compat_sys_aarch32_ptrace(void); #undef __SYSCALL #define __SYSCALL(nr, sym) [nr] = sym, diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 061265f..c38d068 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -75,6 +75,12 @@ int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, unsigned long data); int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, unsigned long data); +int ptrace_traceme(void); +struct task_struct *ptrace_get_task_struct(pid_t pid); +int ptrace_attach(struct task_struct *task, long request, + unsigned long addr, unsigned long flags); +int ptrace_check_attach(struct task_struct *child, bool ignore_state); +void ptrace_unfreeze_traced(struct task_struct *task); /** * ptrace_parent - return the task that is tracing the given task diff --git a/kernel/ptrace.c b/kernel/ptrace.c index b760bae..8f688ae 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -137,7 +137,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) return ret; } -static void ptrace_unfreeze_traced(struct task_struct *task) +void ptrace_unfreeze_traced(struct task_struct *task) { if (task->state != __TASK_TRACED) return; @@ -169,7 +169,7 @@ static void ptrace_unfreeze_traced(struct task_struct *task) * RETURNS: * 0 on success, -ESRCH if %child is not ready. */ -static int ptrace_check_attach(struct task_struct *child, bool ignore_state) +int ptrace_check_attach(struct task_struct *child, bool ignore_state) { int ret = -ESRCH; @@ -270,7 +270,7 @@ bool ptrace_may_access(struct task_struct *task, unsigned int mode) return !err; } -static int ptrace_attach(struct task_struct *task, long request, +int ptrace_attach(struct task_struct *task, long request, unsigned long addr, unsigned long flags) { @@ -378,7 +378,7 @@ out: * Performs checks and sets PT_PTRACED. * Should be used by all ptrace implementations for PTRACE_TRACEME. */ -static int ptrace_traceme(void) + int ptrace_traceme(void) { int ret = -EPERM; @@ -1028,7 +1028,7 @@ int ptrace_request(struct task_struct *child, long request, return ret; } -static struct task_struct *ptrace_get_task_struct(pid_t pid) +struct task_struct *ptrace_get_task_struct(pid_t pid) { struct task_struct *child; -- 2.5.0