From 19397e8b546d20226153dafe5dce34c4393752c4 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 27 Jan 2022 11:17:32 -0600 Subject: ptrace: Move ptrace_report_syscall into ptrace.h Move ptrace_report_syscall from tracehook.h into ptrace.h where it belongs. Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20220309162454.123006-1-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" --- include/linux/ptrace.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/ptrace.h') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 8aee2945ff08..91b1074edb4c 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -413,4 +413,31 @@ static inline void user_single_step_report(struct pt_regs *regs) extern int task_current_syscall(struct task_struct *target, struct syscall_info *info); extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact); + +/* + * ptrace report for syscall entry and exit looks identical. + */ +static inline int ptrace_report_syscall(unsigned long message) +{ + int ptrace = current->ptrace; + + if (!(ptrace & PT_PTRACED)) + return 0; + + current->ptrace_message = message; + ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); + + /* + * this isn't the same as continuing with a signal, but it will do + * for normal use. strace only continues with a signal if the + * stopping signal is not SIGTRAP. -brl + */ + if (current->exit_code) { + send_sig(current->exit_code, current, 1); + current->exit_code = 0; + } + + current->ptrace_message = 0; + return fatal_signal_pending(current); +} #endif -- cgit v1.2.3 From 153474ba1a4aed0a7b797b4c2be8c35c7a4e57bd Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 27 Jan 2022 11:46:37 -0600 Subject: ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h Rename tracehook_report_syscall_{entry,exit} to ptrace_report_syscall_{entry,exit} and place them in ptrace.h There is no longer any generic tracehook infractructure so make these ptrace specific functions ptrace specific. Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20220309162454.123006-3-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" --- arch/Kconfig | 2 +- arch/alpha/kernel/ptrace.c | 5 ++-- arch/arc/kernel/ptrace.c | 5 ++-- arch/arm/kernel/ptrace.c | 5 ++-- arch/arm64/kernel/ptrace.c | 7 +++-- arch/csky/kernel/ptrace.c | 5 ++-- arch/h8300/kernel/ptrace.c | 5 ++-- arch/hexagon/kernel/traps.c | 6 ++--- arch/ia64/kernel/ptrace.c | 4 +-- arch/m68k/kernel/ptrace.c | 6 ++--- arch/microblaze/kernel/ptrace.c | 5 ++-- arch/mips/kernel/ptrace.c | 5 ++-- arch/nds32/include/asm/syscall.h | 2 +- arch/nds32/kernel/ptrace.c | 5 ++-- arch/nios2/kernel/ptrace.c | 5 ++-- arch/openrisc/kernel/ptrace.c | 5 ++-- arch/parisc/kernel/ptrace.c | 7 +++-- arch/powerpc/kernel/ptrace/ptrace.c | 8 +++--- arch/riscv/kernel/ptrace.c | 5 ++-- arch/sh/kernel/ptrace_32.c | 5 ++-- arch/sparc/kernel/ptrace_32.c | 5 ++-- arch/sparc/kernel/ptrace_64.c | 5 ++-- arch/um/kernel/ptrace.c | 5 ++-- arch/xtensa/kernel/ptrace.c | 5 ++-- include/asm-generic/syscall.h | 2 +- include/linux/entry-common.h | 6 ++--- include/linux/ptrace.h | 51 +++++++++++++++++++++++++++++++++++++ include/linux/tracehook.h | 51 ------------------------------------- include/uapi/linux/ptrace.h | 2 +- kernel/entry/common.c | 1 + 30 files changed, 109 insertions(+), 126 deletions(-) (limited to 'include/linux/ptrace.h') diff --git a/arch/Kconfig b/arch/Kconfig index 678a80713b21..a517a949eb1d 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -217,7 +217,7 @@ config TRACE_IRQFLAGS_SUPPORT # asm/syscall.h supplying asm-generic/syscall.h interface # linux/regset.h user_regset interfaces # CORE_DUMP_USE_REGSET #define'd in linux/elf.h -# TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} +# TIF_SYSCALL_TRACE calls ptrace_report_syscall_{entry,exit} # TIF_NOTIFY_RESUME calls tracehook_notify_resume() # signal delivery calls tracehook_signal_handler() # diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c index 8c43212ae38e..a1a239ea002d 100644 --- a/arch/alpha/kernel/ptrace.c +++ b/arch/alpha/kernel/ptrace.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include @@ -323,7 +322,7 @@ asmlinkage unsigned long syscall_trace_enter(void) unsigned long ret = 0; struct pt_regs *regs = current_pt_regs(); if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(current_pt_regs())) + ptrace_report_syscall_entry(current_pt_regs())) ret = -1UL; audit_syscall_entry(regs->r0, regs->r16, regs->r17, regs->r18, regs->r19); return ret ?: current_pt_regs()->r0; @@ -334,5 +333,5 @@ syscall_trace_leave(void) { audit_syscall_exit(current_pt_regs()); if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(current_pt_regs(), 0); + ptrace_report_syscall_exit(current_pt_regs(), 0); } diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c index 883391977fdf..54b419ac8bda 100644 --- a/arch/arc/kernel/ptrace.c +++ b/arch/arc/kernel/ptrace.c @@ -4,7 +4,6 @@ */ #include -#include #include #include #include @@ -258,7 +257,7 @@ long arch_ptrace(struct task_struct *child, long request, asmlinkage int syscall_trace_entry(struct pt_regs *regs) { - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) return ULONG_MAX; return regs->r8; @@ -266,5 +265,5 @@ asmlinkage int syscall_trace_entry(struct pt_regs *regs) asmlinkage void syscall_trace_exit(struct pt_regs *regs) { - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); } diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index e5aa3237853d..bfe88c6e60d5 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include @@ -843,8 +842,8 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) regs->ARM_ip = dir; if (dir == PTRACE_SYSCALL_EXIT) - tracehook_report_syscall_exit(regs, 0); - else if (tracehook_report_syscall_entry(regs)) + ptrace_report_syscall_exit(regs, 0); + else if (ptrace_report_syscall_entry(regs)) current_thread_info()->abi_syscall = -1; regs->ARM_ip = ip; diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index b7845575f86f..230a47b9189e 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include @@ -1818,11 +1817,11 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) regs->regs[regno] = dir; if (dir == PTRACE_SYSCALL_ENTER) { - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) forget_syscall(regs); regs->regs[regno] = saved_reg; } else if (!test_thread_flag(TIF_SINGLESTEP)) { - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); regs->regs[regno] = saved_reg; } else { regs->regs[regno] = saved_reg; @@ -1832,7 +1831,7 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir) * tracer modifications to the registers may have rewound the * state machine. */ - tracehook_report_syscall_exit(regs, 1); + ptrace_report_syscall_exit(regs, 1); } } diff --git a/arch/csky/kernel/ptrace.c b/arch/csky/kernel/ptrace.c index 1a5f54e0d272..0f7e7b653c72 100644 --- a/arch/csky/kernel/ptrace.c +++ b/arch/csky/kernel/ptrace.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include @@ -321,7 +320,7 @@ long arch_ptrace(struct task_struct *child, long request, asmlinkage int syscall_trace_enter(struct pt_regs *regs) { if (test_thread_flag(TIF_SYSCALL_TRACE)) - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) return -1; if (secure_computing() == -1) @@ -339,7 +338,7 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs) audit_syscall_exit(regs); if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) trace_sys_exit(regs, syscall_get_return_value(current, regs)); diff --git a/arch/h8300/kernel/ptrace.c b/arch/h8300/kernel/ptrace.c index a11db009d0ea..a9898b27b756 100644 --- a/arch/h8300/kernel/ptrace.c +++ b/arch/h8300/kernel/ptrace.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include @@ -174,7 +173,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) long ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs)) + ptrace_report_syscall_entry(regs)) /* * Tracing decided this syscall should not happen. * We'll return a bogus call number to get an ENOSYS @@ -196,5 +195,5 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } diff --git a/arch/hexagon/kernel/traps.c b/arch/hexagon/kernel/traps.c index 1240f038cce0..6447763ce5a9 100644 --- a/arch/hexagon/kernel/traps.c +++ b/arch/hexagon/kernel/traps.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include #include #include @@ -348,7 +348,7 @@ void do_trap0(struct pt_regs *regs) /* allow strace to catch syscall args */ if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs))) + ptrace_report_syscall_entry(regs))) return; /* return -ENOSYS somewhere? */ /* Interrupts should be re-enabled for syscall processing */ @@ -386,7 +386,7 @@ void do_trap0(struct pt_regs *regs) /* allow strace to get the syscall return state */ if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE))) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); break; case TRAP_DEBUG: diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 6a1439eaa050..6af64aae087d 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1217,7 +1217,7 @@ syscall_trace_enter (long arg0, long arg1, long arg2, long arg3, struct pt_regs regs) { if (test_thread_flag(TIF_SYSCALL_TRACE)) - if (tracehook_report_syscall_entry(®s)) + if (ptrace_report_syscall_entry(®s)) return -ENOSYS; /* copy user rbs to kernel rbs */ @@ -1243,7 +1243,7 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3, step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(®s, step); + ptrace_report_syscall_exit(®s, step); /* copy user rbs to kernel rbs */ if (test_thread_flag(TIF_RESTORE_RSE)) diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c index aa3a0b8d07e9..a0c99fe3118e 100644 --- a/arch/m68k/kernel/ptrace.c +++ b/arch/m68k/kernel/ptrace.c @@ -19,7 +19,7 @@ #include #include #include -#include +#include #include #include @@ -282,13 +282,13 @@ asmlinkage int syscall_trace_enter(void) int ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE)) - ret = tracehook_report_syscall_entry(task_pt_regs(current)); + ret = ptrace_report_syscall_entry(task_pt_regs(current)); return ret; } asmlinkage void syscall_trace_leave(void) { if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(task_pt_regs(current), 0); + ptrace_report_syscall_exit(task_pt_regs(current), 0); } #endif /* CONFIG_COLDFIRE */ diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c index badd286882ae..5234d0c1dcaa 100644 --- a/arch/microblaze/kernel/ptrace.c +++ b/arch/microblaze/kernel/ptrace.c @@ -33,7 +33,6 @@ #include #include #include -#include #include #include @@ -140,7 +139,7 @@ asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs) secure_computing_strict(regs->r12); if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs)) + ptrace_report_syscall_entry(regs)) /* * Tracing decided this syscall should not happen. * We'll return a bogus call number to get an ENOSYS @@ -161,7 +160,7 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } void ptrace_disable(struct task_struct *child) diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index db7c5be1d4a3..567aec4abac0 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include #include @@ -1317,7 +1316,7 @@ asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall) current_thread_info()->syscall = syscall; if (test_thread_flag(TIF_SYSCALL_TRACE)) { - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) return -1; syscall = current_thread_info()->syscall; } @@ -1376,7 +1375,7 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs) trace_sys_exit(regs, regs_return_value(regs)); if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); user_enter(); } diff --git a/arch/nds32/include/asm/syscall.h b/arch/nds32/include/asm/syscall.h index 90aa56c94af1..04d55ce18d50 100644 --- a/arch/nds32/include/asm/syscall.h +++ b/arch/nds32/include/asm/syscall.h @@ -39,7 +39,7 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs) * * It's only valid to call this when @task is stopped for system * call exit tracing (due to TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT), - * after tracehook_report_syscall_entry() returned nonzero to prevent + * after ptrace_report_syscall_entry() returned nonzero to prevent * the system call from taking place. * * This rolls back the register state in @regs so it's as if the diff --git a/arch/nds32/kernel/ptrace.c b/arch/nds32/kernel/ptrace.c index d0eda870fbc2..6a6988cf689d 100644 --- a/arch/nds32/kernel/ptrace.c +++ b/arch/nds32/kernel/ptrace.c @@ -3,7 +3,6 @@ #include #include -#include #include #include @@ -103,7 +102,7 @@ void user_disable_single_step(struct task_struct *child) asmlinkage int syscall_trace_enter(struct pt_regs *regs) { if (test_thread_flag(TIF_SYSCALL_TRACE)) { - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) forget_syscall(regs); } return regs->syscallno; @@ -113,6 +112,6 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs) { int step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } diff --git a/arch/nios2/kernel/ptrace.c b/arch/nios2/kernel/ptrace.c index a6ea9e1b4f61..cd62f310778b 100644 --- a/arch/nios2/kernel/ptrace.c +++ b/arch/nios2/kernel/ptrace.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include @@ -134,7 +133,7 @@ asmlinkage int do_syscall_trace_enter(void) int ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE)) - ret = tracehook_report_syscall_entry(task_pt_regs(current)); + ret = ptrace_report_syscall_entry(task_pt_regs(current)); return ret; } @@ -142,5 +141,5 @@ asmlinkage int do_syscall_trace_enter(void) asmlinkage void do_syscall_trace_exit(void) { if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(task_pt_regs(current), 0); + ptrace_report_syscall_exit(task_pt_regs(current), 0); } diff --git a/arch/openrisc/kernel/ptrace.c b/arch/openrisc/kernel/ptrace.c index 4d60ae2a12fa..b971740fc2aa 100644 --- a/arch/openrisc/kernel/ptrace.c +++ b/arch/openrisc/kernel/ptrace.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include @@ -159,7 +158,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) long ret = 0; if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs)) + ptrace_report_syscall_entry(regs)) /* * Tracing decided this syscall should not happen. * We'll return a bogus call number to get an ENOSYS @@ -181,5 +180,5 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index 65de6c4c9354..96ef6a6b66e5 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -316,7 +315,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, long do_syscall_trace_enter(struct pt_regs *regs) { if (test_thread_flag(TIF_SYSCALL_TRACE)) { - int rc = tracehook_report_syscall_entry(regs); + int rc = ptrace_report_syscall_entry(regs); /* * As tracesys_next does not set %r28 to -ENOSYS @@ -327,7 +326,7 @@ long do_syscall_trace_enter(struct pt_regs *regs) if (rc) { /* * A nonzero return code from - * tracehook_report_syscall_entry() tells us + * ptrace_report_syscall_entry() tells us * to prevent the syscall execution. Skip * the syscall call and the syscall restart handling. * @@ -381,7 +380,7 @@ void do_syscall_trace_exit(struct pt_regs *regs) #endif if (stepping || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, stepping); + ptrace_report_syscall_exit(regs, stepping); } diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c index c43f77e2ac31..f394b0d6473f 100644 --- a/arch/powerpc/kernel/ptrace/ptrace.c +++ b/arch/powerpc/kernel/ptrace/ptrace.c @@ -16,7 +16,7 @@ */ #include -#include +#include #include #include #include @@ -263,12 +263,12 @@ long do_syscall_trace_enter(struct pt_regs *regs) flags = read_thread_flags() & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE); if (flags) { - int rc = tracehook_report_syscall_entry(regs); + int rc = ptrace_report_syscall_entry(regs); if (unlikely(flags & _TIF_SYSCALL_EMU)) { /* * A nonzero return code from - * tracehook_report_syscall_entry() tells us to prevent + * ptrace_report_syscall_entry() tells us to prevent * the syscall execution, but we are not going to * execute it anyway. * @@ -334,7 +334,7 @@ void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } void __init pt_regs_check(void); diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c index a89243730153..793c7da0554b 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -17,7 +17,6 @@ #include #include #include -#include #define CREATE_TRACE_POINTS #include @@ -241,7 +240,7 @@ long arch_ptrace(struct task_struct *child, long request, __visible int do_syscall_trace_enter(struct pt_regs *regs) { if (test_thread_flag(TIF_SYSCALL_TRACE)) - if (tracehook_report_syscall_entry(regs)) + if (ptrace_report_syscall_entry(regs)) return -1; /* @@ -266,7 +265,7 @@ __visible void do_syscall_trace_exit(struct pt_regs *regs) audit_syscall_exit(regs); if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c index 5281685f6ad1..d417988d9770 100644 --- a/arch/sh/kernel/ptrace_32.c +++ b/arch/sh/kernel/ptrace_32.c @@ -20,7 +20,6 @@ #include #include #include -#include #include #include #include @@ -456,7 +455,7 @@ long arch_ptrace(struct task_struct *child, long request, asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) { if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs)) { + ptrace_report_syscall_entry(regs)) { regs->regs[0] = -ENOSYS; return -1; } @@ -484,5 +483,5 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } diff --git a/arch/sparc/kernel/ptrace_32.c b/arch/sparc/kernel/ptrace_32.c index 5318174a0268..e7db48acb838 100644 --- a/arch/sparc/kernel/ptrace_32.c +++ b/arch/sparc/kernel/ptrace_32.c @@ -21,7 +21,6 @@ #include #include #include -#include #include #include @@ -439,9 +438,9 @@ asmlinkage int syscall_trace(struct pt_regs *regs, int syscall_exit_p) if (test_thread_flag(TIF_SYSCALL_TRACE)) { if (syscall_exit_p) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); else - ret = tracehook_report_syscall_entry(regs); + ret = ptrace_report_syscall_entry(regs); } return ret; diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c index 2b92155db8a5..86a7eb5c27ba 100644 --- a/arch/sparc/kernel/ptrace_64.c +++ b/arch/sparc/kernel/ptrace_64.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include #include @@ -1095,7 +1094,7 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) user_exit(); if (test_thread_flag(TIF_SYSCALL_TRACE)) - ret = tracehook_report_syscall_entry(regs); + ret = ptrace_report_syscall_entry(regs); if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_sys_enter(regs, regs->u_regs[UREG_G1]); @@ -1118,7 +1117,7 @@ asmlinkage void syscall_trace_leave(struct pt_regs *regs) trace_sys_exit(regs, regs->u_regs[UREG_I0]); if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); if (test_thread_flag(TIF_NOHZ)) user_enter(); diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index b425f47bddbb..bfaf6ab1ac03 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -6,7 +6,6 @@ #include #include #include -#include #include #include @@ -135,7 +134,7 @@ int syscall_trace_enter(struct pt_regs *regs) if (!test_thread_flag(TIF_SYSCALL_TRACE)) return 0; - return tracehook_report_syscall_entry(regs); + return ptrace_report_syscall_entry(regs); } void syscall_trace_leave(struct pt_regs *regs) @@ -151,7 +150,7 @@ void syscall_trace_leave(struct pt_regs *regs) if (!test_thread_flag(TIF_SYSCALL_TRACE)) return; - tracehook_report_syscall_exit(regs, 0); + ptrace_report_syscall_exit(regs, 0); /* force do_signal() --> is_syscall() */ if (ptraced & PT_PTRACED) set_thread_flag(TIF_SIGPENDING); diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index bb3f4797d212..323c678a691f 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #define CREATE_TRACE_POINTS @@ -550,7 +549,7 @@ int do_syscall_trace_enter(struct pt_regs *regs) regs->areg[2] = -ENOSYS; if (test_thread_flag(TIF_SYSCALL_TRACE) && - tracehook_report_syscall_entry(regs)) { + ptrace_report_syscall_entry(regs)) { regs->areg[2] = -ENOSYS; regs->syscall = NO_SYSCALL; return 0; @@ -583,5 +582,5 @@ void do_syscall_trace_leave(struct pt_regs *regs) step = test_thread_flag(TIF_SINGLESTEP); if (step || test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h index 81695eb02a12..5a80fe728dc8 100644 --- a/include/asm-generic/syscall.h +++ b/include/asm-generic/syscall.h @@ -44,7 +44,7 @@ int syscall_get_nr(struct task_struct *task, struct pt_regs *regs); * * It's only valid to call this when @task is stopped for system * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or - * %SYSCALL_WORK_SYSCALL_AUDIT), after tracehook_report_syscall_entry() + * %SYSCALL_WORK_SYSCALL_AUDIT), after ptrace_report_syscall_entry() * returned nonzero to prevent the system call from taking place. * * This rolls back the register state in @regs so it's as if the diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 2e2b8d6140ed..a670e9fba7a9 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -3,7 +3,7 @@ #define __LINUX_ENTRYCOMMON_H #include -#include +#include #include #include #include @@ -95,7 +95,7 @@ static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs #ifndef arch_syscall_enter_tracehook static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs) { - return tracehook_report_syscall_entry(regs); + return ptrace_report_syscall_entry(regs); } #endif @@ -294,7 +294,7 @@ static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step); #ifndef arch_syscall_exit_tracehook static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step) { - tracehook_report_syscall_exit(regs, step); + ptrace_report_syscall_exit(regs, step); } #endif diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 91b1074edb4c..5310f43e4762 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -440,4 +440,55 @@ static inline int ptrace_report_syscall(unsigned long message) current->ptrace_message = 0; return fatal_signal_pending(current); } + +/** + * ptrace_report_syscall_entry - task is about to attempt a system call + * @regs: user register state of current task + * + * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just + * entered the kernel for a system call. Full user register state is + * available here. Changing the values in @regs can affect the system + * call number and arguments to be tried. It is safe to block here, + * preventing the system call from beginning. + * + * Returns zero normally, or nonzero if the calling arch code should abort + * the system call. That must prevent normal entry so no system call is + * made. If @task ever returns to user mode after this, its register state + * is unspecified, but should be something harmless like an %ENOSYS error + * return. It should preserve enough information so that syscall_rollback() + * can work (see asm-generic/syscall.h). + * + * Called without locks, just after entering kernel mode. + */ +static inline __must_check int ptrace_report_syscall_entry( + struct pt_regs *regs) +{ + return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY); +} + +/** + * ptrace_report_syscall_exit - task has just finished a system call + * @regs: user register state of current task + * @step: nonzero if simulating single-step or block-step + * + * This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when + * the current task has just finished an attempted system call. Full + * user register state is available here. It is safe to block here, + * preventing signals from being processed. + * + * If @step is nonzero, this report is also in lieu of the normal + * trap that would follow the system call instruction because + * user_enable_block_step() or user_enable_single_step() was used. + * In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set. + * + * Called without locks, just before checking for pending signals. + */ +static inline void ptrace_report_syscall_exit(struct pt_regs *regs, int step) +{ + if (step) + user_single_step_report(regs); + else + ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT); +} #endif diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 998bc3863559..819e82ac09bd 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -52,57 +52,6 @@ struct linux_binprm; -/** - * tracehook_report_syscall_entry - task is about to attempt a system call - * @regs: user register state of current task - * - * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or - * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just - * entered the kernel for a system call. Full user register state is - * available here. Changing the values in @regs can affect the system - * call number and arguments to be tried. It is safe to block here, - * preventing the system call from beginning. - * - * Returns zero normally, or nonzero if the calling arch code should abort - * the system call. That must prevent normal entry so no system call is - * made. If @task ever returns to user mode after this, its register state - * is unspecified, but should be something harmless like an %ENOSYS error - * return. It should preserve enough information so that syscall_rollback() - * can work (see asm-generic/syscall.h). - * - * Called without locks, just after entering kernel mode. - */ -static inline __must_check int tracehook_report_syscall_entry( - struct pt_regs *regs) -{ - return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY); -} - -/** - * tracehook_report_syscall_exit - task has just finished a system call - * @regs: user register state of current task - * @step: nonzero if simulating single-step or block-step - * - * This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when - * the current task has just finished an attempted system call. Full - * user register state is available here. It is safe to block here, - * preventing signals from being processed. - * - * If @step is nonzero, this report is also in lieu of the normal - * trap that would follow the system call instruction because - * user_enable_block_step() or user_enable_single_step() was used. - * In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set. - * - * Called without locks, just before checking for pending signals. - */ -static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) -{ - if (step) - user_single_step_report(regs); - else - ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT); -} - /** * tracehook_signal_handler - signal handler setup is complete * @stepping: nonzero if debugger single-step or block-step in use diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h index 3747bf816f9a..b7af92e07d1f 100644 --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -114,7 +114,7 @@ struct ptrace_rseq_configuration { /* * These values are stored in task->ptrace_message - * by tracehook_report_syscall_* to describe the current syscall-stop. + * by ptrace_report_syscall_* to describe the current syscall-stop. */ #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 diff --git a/kernel/entry/common.c b/kernel/entry/common.c index bad713684c2e..f52e57c4d6d8 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -2,6 +2,7 @@ #include #include +#include #include #include #include -- cgit v1.2.3 From 336d4b814bf078fa698488632c19beca47308896 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 27 Jan 2022 12:15:32 -0600 Subject: ptrace: Move setting/clearing ptrace_message into ptrace_stop Today ptrace_message is easy to overlook as it not a core part of ptrace_stop. It has been overlooked so much that there are places that set ptrace_message and don't clear it, and places that never set it. So if you get an unlucky sequence of events the ptracer may be able to read a ptrace_message that does not apply to the current ptrace stop. Move setting of ptrace_message into ptrace_stop so that it always gets set before the stop, and always gets cleared after the stop. This prevents non-sense from being reported to userspace and makes ptrace_message more visible in the ptrace helper functions so that kernel developers can see it. Link: https://lkml.kernel.org/r/87bky67qfv.fsf_-_@email.froward.int.ebiederm.org Acked-by: Oleg Nesterov Reviewed-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- include/linux/ptrace.h | 9 +++------ include/uapi/linux/ptrace.h | 2 +- kernel/signal.c | 21 ++++++++++++--------- 3 files changed, 16 insertions(+), 16 deletions(-) (limited to 'include/linux/ptrace.h') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 5310f43e4762..3e6b46e2b7be 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -60,7 +60,7 @@ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned extern void ptrace_disable(struct task_struct *); extern int ptrace_request(struct task_struct *child, long request, unsigned long addr, unsigned long data); -extern void ptrace_notify(int exit_code); +extern void ptrace_notify(int exit_code, unsigned long message); extern void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, const struct cred *ptracer_cred); @@ -155,8 +155,7 @@ static inline bool ptrace_event_enabled(struct task_struct *task, int event) static inline void ptrace_event(int event, unsigned long message) { if (unlikely(ptrace_event_enabled(current, event))) { - current->ptrace_message = message; - ptrace_notify((event << 8) | SIGTRAP); + ptrace_notify((event << 8) | SIGTRAP, message); } else if (event == PTRACE_EVENT_EXEC) { /* legacy EXEC report via SIGTRAP */ if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) @@ -424,8 +423,7 @@ static inline int ptrace_report_syscall(unsigned long message) if (!(ptrace & PT_PTRACED)) return 0; - current->ptrace_message = message; - ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); + ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0), message); /* * this isn't the same as continuing with a signal, but it will do @@ -437,7 +435,6 @@ static inline int ptrace_report_syscall(unsigned long message) current->exit_code = 0; } - current->ptrace_message = 0; return fatal_signal_pending(current); } diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h index b7af92e07d1f..195ae64a8c87 100644 --- a/include/uapi/linux/ptrace.h +++ b/include/uapi/linux/ptrace.h @@ -114,7 +114,7 @@ struct ptrace_rseq_configuration { /* * These values are stored in task->ptrace_message - * by ptrace_report_syscall_* to describe the current syscall-stop. + * by ptrace_stop to describe the current syscall-stop. */ #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 diff --git a/kernel/signal.c b/kernel/signal.c index c2dee5420567..a49ac7149256 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2191,7 +2191,8 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, * If we actually decide not to stop at all because the tracer * is gone, we keep current->exit_code unless clear_code. */ -static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t *info) +static void ptrace_stop(int exit_code, int why, int clear_code, + unsigned long message, kernel_siginfo_t *info) __releases(¤t->sighand->siglock) __acquires(¤t->sighand->siglock) { @@ -2237,6 +2238,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t */ smp_wmb(); + current->ptrace_message = message; current->last_siginfo = info; current->exit_code = exit_code; @@ -2315,6 +2317,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t */ spin_lock_irq(¤t->sighand->siglock); current->last_siginfo = NULL; + current->ptrace_message = 0; /* LISTENING can be set only during STOP traps, clear it */ current->jobctl &= ~JOBCTL_LISTENING; @@ -2327,7 +2330,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t recalc_sigpending_tsk(current); } -static void ptrace_do_notify(int signr, int exit_code, int why) +static void ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) { kernel_siginfo_t info; @@ -2338,17 +2341,17 @@ static void ptrace_do_notify(int signr, int exit_code, int why) info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); /* Let the debugger run. */ - ptrace_stop(exit_code, why, 1, &info); + ptrace_stop(exit_code, why, 1, message, &info); } -void ptrace_notify(int exit_code) +void ptrace_notify(int exit_code, unsigned long message) { BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); if (unlikely(task_work_pending(current))) task_work_run(); spin_lock_irq(¤t->sighand->siglock); - ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED); + ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED, message); spin_unlock_irq(¤t->sighand->siglock); } @@ -2504,10 +2507,10 @@ static void do_jobctl_trap(void) signr = SIGTRAP; WARN_ON_ONCE(!signr); ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8), - CLD_STOPPED); + CLD_STOPPED, 0); } else { WARN_ON_ONCE(!signr); - ptrace_stop(signr, CLD_STOPPED, 0, NULL); + ptrace_stop(signr, CLD_STOPPED, 0, 0, NULL); current->exit_code = 0; } } @@ -2561,7 +2564,7 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type) * comment in dequeue_signal(). */ current->jobctl |= JOBCTL_STOP_DEQUEUED; - ptrace_stop(signr, CLD_TRAPPED, 0, info); + ptrace_stop(signr, CLD_TRAPPED, 0, 0, info); /* We're back. Did the debugger cancel the sig? */ signr = current->exit_code; @@ -2891,7 +2894,7 @@ static void signal_delivered(struct ksignal *ksig, int stepping) if (current->sas_ss_flags & SS_AUTODISARM) sas_ss_reset(current); if (stepping) - ptrace_notify(SIGTRAP); + ptrace_notify(SIGTRAP, 0); } void signal_setup_done(int failed, struct ksignal *ksig, int stepping) -- cgit v1.2.3 From 6487d1dab837214ec2fd3f0ddd5f787e63be7c20 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 27 Jan 2022 12:19:13 -0600 Subject: ptrace: Return the signal to continue with from ptrace_stop The signal a task should continue with after a ptrace stop is inconsistently read, cleared, and sent. Solve this by reading and clearing the signal to be sent in ptrace_stop. In an ideal world everything except ptrace_signal would share a common implementation of continuing with the signal, so ptracers could count on the signal they ask to continue with actually being delivered. For now retain bug compatibility and just return with the signal number the ptracer requested the code continue with. Link: https://lkml.kernel.org/r/875yoe7qdp.fsf_-_@email.froward.int.ebiederm.org Reviewed-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- include/linux/ptrace.h | 12 ++++++------ kernel/signal.c | 32 +++++++++++++++++++------------- 2 files changed, 25 insertions(+), 19 deletions(-) (limited to 'include/linux/ptrace.h') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 3e6b46e2b7be..15b3d176b6b4 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -60,7 +60,7 @@ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned extern void ptrace_disable(struct task_struct *); extern int ptrace_request(struct task_struct *child, long request, unsigned long addr, unsigned long data); -extern void ptrace_notify(int exit_code, unsigned long message); +extern int ptrace_notify(int exit_code, unsigned long message); extern void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, const struct cred *ptracer_cred); @@ -419,21 +419,21 @@ extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oa static inline int ptrace_report_syscall(unsigned long message) { int ptrace = current->ptrace; + int signr; if (!(ptrace & PT_PTRACED)) return 0; - ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0), message); + signr = ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0), + message); /* * this isn't the same as continuing with a signal, but it will do * for normal use. strace only continues with a signal if the * stopping signal is not SIGTRAP. -brl */ - if (current->exit_code) { - send_sig(current->exit_code, current, 1); - current->exit_code = 0; - } + if (signr) + send_sig(signr, current, 1); return fatal_signal_pending(current); } diff --git a/kernel/signal.c b/kernel/signal.c index a49ac7149256..f1c4ab85833c 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2188,15 +2188,17 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, * That makes it a way to test a stopped process for * being ptrace-stopped vs being job-control-stopped. * - * If we actually decide not to stop at all because the tracer - * is gone, we keep current->exit_code unless clear_code. + * Returns the signal the ptracer requested the code resume + * with. If the code did not stop because the tracer is gone, + * the stop signal remains unchanged unless clear_code. */ -static void ptrace_stop(int exit_code, int why, int clear_code, +static int ptrace_stop(int exit_code, int why, int clear_code, unsigned long message, kernel_siginfo_t *info) __releases(¤t->sighand->siglock) __acquires(¤t->sighand->siglock) { bool gstop_done = false; + bool read_code = true; if (arch_ptrace_stop_needed()) { /* @@ -2305,8 +2307,9 @@ static void ptrace_stop(int exit_code, int why, int clear_code, /* tasklist protects us from ptrace_freeze_traced() */ __set_current_state(TASK_RUNNING); + read_code = false; if (clear_code) - current->exit_code = 0; + exit_code = 0; read_unlock(&tasklist_lock); } @@ -2316,8 +2319,11 @@ static void ptrace_stop(int exit_code, int why, int clear_code, * any signal-sending on another CPU that wants to examine it. */ spin_lock_irq(¤t->sighand->siglock); + if (read_code) + exit_code = current->exit_code; current->last_siginfo = NULL; current->ptrace_message = 0; + current->exit_code = 0; /* LISTENING can be set only during STOP traps, clear it */ current->jobctl &= ~JOBCTL_LISTENING; @@ -2328,9 +2334,10 @@ static void ptrace_stop(int exit_code, int why, int clear_code, * This sets TIF_SIGPENDING, but never clears it. */ recalc_sigpending_tsk(current); + return exit_code; } -static void ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) +static int ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) { kernel_siginfo_t info; @@ -2341,18 +2348,21 @@ static void ptrace_do_notify(int signr, int exit_code, int why, unsigned long me info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); /* Let the debugger run. */ - ptrace_stop(exit_code, why, 1, message, &info); + return ptrace_stop(exit_code, why, 1, message, &info); } -void ptrace_notify(int exit_code, unsigned long message) +int ptrace_notify(int exit_code, unsigned long message) { + int signr; + BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); if (unlikely(task_work_pending(current))) task_work_run(); spin_lock_irq(¤t->sighand->siglock); - ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED, message); + signr = ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED, message); spin_unlock_irq(¤t->sighand->siglock); + return signr; } /** @@ -2511,7 +2521,6 @@ static void do_jobctl_trap(void) } else { WARN_ON_ONCE(!signr); ptrace_stop(signr, CLD_STOPPED, 0, 0, NULL); - current->exit_code = 0; } } @@ -2564,15 +2573,12 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type) * comment in dequeue_signal(). */ current->jobctl |= JOBCTL_STOP_DEQUEUED; - ptrace_stop(signr, CLD_TRAPPED, 0, 0, info); + signr = ptrace_stop(signr, CLD_TRAPPED, 0, 0, info); /* We're back. Did the debugger cancel the sig? */ - signr = current->exit_code; if (signr == 0) return signr; - current->exit_code = 0; - /* * Update the siginfo structure if the signal has * changed. If the debugger wanted something -- cgit v1.2.3 From c200e4bb44e80b343c09841e7caaaca0aac5e5fa Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 26 Apr 2022 16:30:17 -0500 Subject: ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate single stepping is a little confusing and worse changing tsk->ptrace without locking could potentionally cause problems. So use a thread info flag with a better name instead of flag in tsk->ptrace. Remove the definition PT_DTRACE as uml is the last user. Cc: stable@vger.kernel.org Acked-by: Johannes Berg Tested-by: Kees Cook Reviewed-by: Oleg Nesterov Link: https://lkml.kernel.org/r/20220505182645.497868-3-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" --- arch/um/include/asm/thread_info.h | 2 ++ arch/um/kernel/exec.c | 2 +- arch/um/kernel/process.c | 2 +- arch/um/kernel/ptrace.c | 8 ++++---- arch/um/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 1 - 6 files changed, 10 insertions(+), 9 deletions(-) (limited to 'include/linux/ptrace.h') diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h index 1395cbd7e340..c7b4b49826a2 100644 --- a/arch/um/include/asm/thread_info.h +++ b/arch/um/include/asm/thread_info.h @@ -60,6 +60,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_RESTORE_SIGMASK 7 #define TIF_NOTIFY_RESUME 8 #define TIF_SECCOMP 9 /* secure computing */ +#define TIF_SINGLESTEP 10 /* single stepping userspace */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) @@ -68,5 +69,6 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_MEMDIE (1 << TIF_MEMDIE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) +#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) #endif diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index c85e40c72779..58938d75871a 100644 --- a/arch/um/kernel/exec.c +++ b/arch/um/kernel/exec.c @@ -43,7 +43,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp) { PT_REGS_IP(regs) = eip; PT_REGS_SP(regs) = esp; - current->ptrace &= ~PT_DTRACE; + clear_thread_flag(TIF_SINGLESTEP); #ifdef SUBARCH_EXECVE1 SUBARCH_EXECVE1(regs->regs); #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 80504680be08..88c5c7844281 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -335,7 +335,7 @@ int singlestepping(void * t) { struct task_struct *task = t ? t : current; - if (!(task->ptrace & PT_DTRACE)) + if (!test_thread_flag(TIF_SINGLESTEP)) return 0; if (task->thread.singlestep_syscall) diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index bfaf6ab1ac03..5154b27de580 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -11,7 +11,7 @@ void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_DTRACE; + set_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING @@ -21,7 +21,7 @@ void user_enable_single_step(struct task_struct *child) void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_DTRACE; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING @@ -120,7 +120,7 @@ static void send_sigtrap(struct uml_pt_regs *regs, int error_code) } /* - * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and + * XXX Check TIF_SINGLESTEP for singlestepping check and * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check */ int syscall_trace_enter(struct pt_regs *regs) @@ -144,7 +144,7 @@ void syscall_trace_leave(struct pt_regs *regs) audit_syscall_exit(regs); /* Fake a debug trap */ - if (ptraced & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) send_sigtrap(®s->regs, 0); if (!test_thread_flag(TIF_SYSCALL_TRACE)) diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c index 88cd9b5c1b74..ae4658f576ab 100644 --- a/arch/um/kernel/signal.c +++ b/arch/um/kernel/signal.c @@ -53,7 +53,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) unsigned long sp; int err; - if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) + if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED)) singlestep = 1; /* Did we come from a system call? */ @@ -128,7 +128,7 @@ void do_signal(struct pt_regs *regs) * on the host. The tracing thread will check this flag and * PTRACE_SYSCALL if necessary. */ - if (current->ptrace & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) current->thread.singlestep_syscall = is_syscall(PT_REGS_IP(¤t->thread.regs)); diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 15b3d176b6b4..4c06f9f8ef3f 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -30,7 +30,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 -#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ #define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */ -- cgit v1.2.3 From 4a3d2717d140401df7501a95e454180831a0c5af Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 26 Apr 2022 16:45:37 -0500 Subject: ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP xtensa is the last user of the PT_SINGLESTEP flag. Changing tsk->ptrace in user_enable_single_step and user_disable_single_step without locking could potentiallly cause problems. So use a thread info flag instead of a flag in tsk->ptrace. Use TIF_SINGLESTEP that xtensa already had defined but unused. Remove the definitions of PT_SINGLESTEP and PT_BLOCKSTEP as they have no more users. Cc: stable@vger.kernel.org Acked-by: Max Filippov Tested-by: Kees Cook Reviewed-by: Oleg Nesterov Link: https://lkml.kernel.org/r/20220505182645.497868-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" --- arch/xtensa/kernel/ptrace.c | 4 ++-- arch/xtensa/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 6 ------ 3 files changed, 4 insertions(+), 10 deletions(-) (limited to 'include/linux/ptrace.h') diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index 323c678a691f..b952e67cc0cc 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -225,12 +225,12 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_SINGLESTEP; + set_tsk_thread_flag(child, TIF_SINGLESTEP); } void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_SINGLESTEP; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); } /* diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 6f68649e86ba..ac50ec46c8f1 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -473,7 +473,7 @@ static void do_signal(struct pt_regs *regs) /* Set up the stack frame */ ret = setup_frame(&ksig, sigmask_to_save(), regs); signal_setup_done(ret, &ksig, 0); - if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1; return; @@ -499,7 +499,7 @@ static void do_signal(struct pt_regs *regs) /* If there's no signal to deliver, we just restore the saved mask. */ restore_saved_sigmask(); - if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1; return; } diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 4c06f9f8ef3f..c952c5ba8fab 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -46,12 +46,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) -/* single stepping state bits (used on ARM and PA-RISC) */ -#define PT_SINGLESTEP_BIT 31 -#define PT_SINGLESTEP (1<