From 6ea6dd93c9454cc9521134f907bc970d09f460e4 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Tue, 27 Nov 2007 13:02:40 +0100 Subject: ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME arch_ptrace_attach() is a hook that allows the architecture to do book-keeping after a ptrace attach. This patch adds a call to this hook when handling a PTRACE_TRACEME request as well. Currently only one architecture, m32r, implements this hook. When called, it initializes a number of debug trap slots in the ptraced task's thread struct, and it looks to me like this is the right thing to do after a PTRACE_TRACEME request as well, not only after PTRACE_ATTACH. Please correct me if I'm wrong. I want to use this hook on AVR32 to turn the debugging hardware on when a process is actually being debugged and keep it off otherwise. To be able to do this, I need to intercept PTRACE_TRACEME and PTRACE_ATTACH, as well as PTRACE_DETACH and thread exit. The latter two can be handled by existing hooks. Signed-off-by: Haavard Skinnemoen --- kernel/ptrace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index c25db863081d..c719bb9d79ab 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -470,6 +470,8 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data) lock_kernel(); if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); + if (!ret) + arch_ptrace_attach(current); goto out; } -- cgit v1.2.2 From 36df29d7994180cf7f0ccc5d46495855d56d2721 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:51 +0100 Subject: ptrace: generic resume This makes ptrace_request handle all the ptrace requests that wake up the traced task. These do low-level ptrace implementation magic that is not arch-specific and should be kept out of arch code. The implementations on each arch usually do the same thing. The new generic code makes use of the arch_has_single_step macro and generic entry points to handle PTRACE_SINGLESTEP. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/ptrace.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index c719bb9d79ab..fad5f1e8511f 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -366,6 +366,50 @@ static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) return error; } + +#ifdef PTRACE_SINGLESTEP +#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) +#else +#define is_singlestep(request) 0 +#endif + +#ifdef PTRACE_SYSEMU +#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) +#else +#define is_sysemu_singlestep(request) 0 +#endif + +static int ptrace_resume(struct task_struct *child, long request, long data) +{ + if (!valid_signal(data)) + return -EIO; + + if (request == PTRACE_SYSCALL) + set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + else + clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); + +#ifdef TIF_SYSCALL_EMU + if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) + set_tsk_thread_flag(child, TIF_SYSCALL_EMU); + else + clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); +#endif + + if (is_singlestep(request) || is_sysemu_singlestep(request)) { + if (unlikely(!arch_has_single_step())) + return -EIO; + user_enable_single_step(child); + } + else + user_disable_single_step(child); + + child->exit_code = data; + wake_up_process(child); + + return 0; +} + int ptrace_request(struct task_struct *child, long request, long addr, long data) { @@ -390,6 +434,23 @@ int ptrace_request(struct task_struct *child, long request, case PTRACE_DETACH: /* detach a process that was attached. */ ret = ptrace_detach(child, data); break; + +#ifdef PTRACE_SINGLESTEP + case PTRACE_SINGLESTEP: +#endif +#ifdef PTRACE_SYSEMU + case PTRACE_SYSEMU: + case PTRACE_SYSEMU_SINGLESTEP: +#endif + case PTRACE_SYSCALL: + case PTRACE_CONT: + return ptrace_resume(child, request, data); + + case PTRACE_KILL: + if (child->exit_state) /* already dead */ + return 0; + return ptrace_resume(child, request, SIGKILL); + default: break; } -- cgit v1.2.2 From 5b88abbf770a0e1975c668743100f42934f385e8 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:30:53 +0100 Subject: ptrace: generic PTRACE_SINGLEBLOCK This makes ptrace_request handle PTRACE_SINGLEBLOCK along with PTRACE_CONT et al. The new generic code makes use of the arch_has_block_step macro and generic entry points on machines that define them. [ mingo@elte.hu: bugfix ] Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/ptrace.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index fad5f1e8511f..973d727f5e84 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -373,6 +373,12 @@ static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) #define is_singlestep(request) 0 #endif +#ifdef PTRACE_SINGLEBLOCK +#define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) +#else +#define is_singleblock(request) 0 +#endif + #ifdef PTRACE_SYSEMU #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) #else @@ -396,7 +402,11 @@ static int ptrace_resume(struct task_struct *child, long request, long data) clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); #endif - if (is_singlestep(request) || is_sysemu_singlestep(request)) { + if (is_singleblock(request)) { + if (unlikely(!arch_has_block_step())) + return -EIO; + user_enable_block_step(child); + } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { if (unlikely(!arch_has_single_step())) return -EIO; user_enable_single_step(child); @@ -438,6 +448,9 @@ int ptrace_request(struct task_struct *child, long request, #ifdef PTRACE_SINGLESTEP case PTRACE_SINGLESTEP: #endif +#ifdef PTRACE_SINGLEBLOCK + case PTRACE_SINGLEBLOCK: +#endif #ifdef PTRACE_SYSEMU case PTRACE_SYSEMU: case PTRACE_SYSEMU_SINGLESTEP: -- cgit v1.2.2 From 16c3e389e7a7254ff8dc7029ac4fbe996c3c75bf Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:31:47 +0100 Subject: x86: ptrace_request peekdata/pokedata This makes ptrace_request handle {PEEK,POKE}{TEXT,DATA} directly. Every arch_ptrace that could call generic_ptrace_peekdata already has a default case calling ptrace_request, so this keeps things simpler for the arch code. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/ptrace.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 973d727f5e84..e6a99d2793b3 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -426,6 +426,13 @@ int ptrace_request(struct task_struct *child, long request, int ret = -EIO; switch (request) { + case PTRACE_PEEKTEXT: + case PTRACE_PEEKDATA: + return generic_ptrace_peekdata(child, addr, data); + case PTRACE_POKETEXT: + case PTRACE_POKEDATA: + return generic_ptrace_pokedata(child, addr, data); + #ifdef PTRACE_OLDSETOPTIONS case PTRACE_OLDSETOPTIONS: #endif -- cgit v1.2.2 From 032d82d9065dec0e26718eca376c2029e4bd0595 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:31:47 +0100 Subject: x86: compat_ptrace_request This adds a compat_ptrace_request that is the analogue of ptrace_request for the things that 32-on-64 ptrace implementations can share in common. So far there are just a couple of requests handled generically. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/ptrace.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index e6a99d2793b3..ed1c3d56c2cd 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -607,3 +607,41 @@ int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); return (copied == sizeof(data)) ? 0 : -EIO; } + +#ifdef CONFIG_COMPAT +#include + +int compat_ptrace_request(struct task_struct *child, compat_long_t request, + compat_ulong_t addr, compat_ulong_t data) +{ + compat_ulong_t __user *datap = compat_ptr(data); + compat_ulong_t word; + int ret; + + switch (request) { + case PTRACE_PEEKTEXT: + case PTRACE_PEEKDATA: + ret = access_process_vm(child, addr, &word, sizeof(word), 0); + if (ret != sizeof(word)) + ret = -EIO; + else + ret = put_user(word, datap); + break; + + case PTRACE_POKETEXT: + case PTRACE_POKEDATA: + ret = access_process_vm(child, addr, &data, sizeof(data), 1); + ret = (ret != sizeof(data) ? -EIO : 0); + break; + + case PTRACE_GETEVENTMSG: + ret = put_user((compat_ulong_t) child->ptrace_message, datap); + break; + + default: + ret = ptrace_request(child, request, addr, data); + } + + return ret; +} +#endif /* CONFIG_COMPAT */ -- cgit v1.2.2 From c269f19617f508cc5c29c0b064c1a437d7011a46 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:31:48 +0100 Subject: x86: compat_sys_ptrace This adds a generic definition of compat_sys_ptrace that calls compat_arch_ptrace, parallel to sys_ptrace/arch_ptrace. Some machines needing this already define a function by that name. The new generic function is defined only on machines that put #define __ARCH_WANT_COMPAT_SYS_PTRACE into asm/ptrace.h. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/ptrace.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index ed1c3d56c2cd..e6e9b8be4b05 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -644,4 +644,50 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, return ret; } + +#ifdef __ARCH_WANT_COMPAT_SYS_PTRACE +asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, + compat_long_t addr, compat_long_t data) +{ + struct task_struct *child; + long ret; + + /* + * This lock_kernel fixes a subtle race with suid exec + */ + lock_kernel(); + 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) { + ret = ptrace_attach(child); + /* + * Some architectures need to do book-keeping after + * a ptrace attach. + */ + if (!ret) + arch_ptrace_attach(child); + goto out_put_task_struct; + } + + ret = ptrace_check_attach(child, request == PTRACE_KILL); + if (!ret) + ret = compat_arch_ptrace(child, request, addr, data); + + out_put_task_struct: + put_task_struct(child); + out: + unlock_kernel(); + return ret; +} +#endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */ + #endif /* CONFIG_COMPAT */ -- cgit v1.2.2