| Message ID | 20250128091636.GC8601@strace.io (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ptrace: introduce PTRACE_SET_SYSCALL_INFO API | expand |
Le 28/01/2025 à 10:16, Dmitry V. Levin a écrit : > Similar to syscall_set_arguments() that complements > syscall_get_arguments(), introduce syscall_set_nr() > that complements syscall_get_nr(). > > syscall_set_nr() is going to be needed along with > syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK > architectures to implement PTRACE_SET_SYSCALL_INFO API. > > Signed-off-by: Dmitry V. Levin <ldv@strace.io> > Tested-by: Charlie Jenkins <charlie@rivosinc.com> > Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> > --- > arch/arc/include/asm/syscall.h | 11 +++++++++++ > arch/arm/include/asm/syscall.h | 24 ++++++++++++++++++++++++ > arch/arm64/include/asm/syscall.h | 16 ++++++++++++++++ > arch/hexagon/include/asm/syscall.h | 7 +++++++ > arch/loongarch/include/asm/syscall.h | 7 +++++++ > arch/m68k/include/asm/syscall.h | 7 +++++++ > arch/microblaze/include/asm/syscall.h | 7 +++++++ > arch/mips/include/asm/syscall.h | 14 ++++++++++++++ > arch/nios2/include/asm/syscall.h | 5 +++++ > arch/openrisc/include/asm/syscall.h | 6 ++++++ > arch/parisc/include/asm/syscall.h | 7 +++++++ > arch/powerpc/include/asm/syscall.h | 10 ++++++++++ > arch/riscv/include/asm/syscall.h | 7 +++++++ > arch/s390/include/asm/syscall.h | 12 ++++++++++++ > arch/sh/include/asm/syscall_32.h | 12 ++++++++++++ > arch/sparc/include/asm/syscall.h | 12 ++++++++++++ > arch/um/include/asm/syscall-generic.h | 5 +++++ > arch/x86/include/asm/syscall.h | 7 +++++++ > arch/xtensa/include/asm/syscall.h | 7 +++++++ > include/asm-generic/syscall.h | 14 ++++++++++++++ > 20 files changed, 197 insertions(+) > > diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h > index 76020b66286b..712daa90e643 100644 > --- a/arch/arm64/include/asm/syscall.h > +++ b/arch/arm64/include/asm/syscall.h > @@ -61,6 +61,22 @@ static inline void syscall_set_return_value(struct task_struct *task, > regs->regs[0] = val; > } > > +static inline void syscall_set_nr(struct task_struct *task, > + struct pt_regs *regs, > + int nr) > +{ > + regs->syscallno = nr; > + if (nr == -1) { > + /* > + * When the syscall number is set to -1, the syscall will be > + * skipped. In this case the syscall return value has to be > + * set explicitly, otherwise the first syscall argument is > + * returned as the syscall return value. > + */ > + syscall_set_return_value(task, regs, -ENOSYS, 0); > + } > +} > + > #define SYSCALL_MAX_ARGS 6 > > static inline void syscall_get_arguments(struct task_struct *task, > diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h > index 521f279e6b33..7505dcfed247 100644 > --- a/arch/powerpc/include/asm/syscall.h > +++ b/arch/powerpc/include/asm/syscall.h > @@ -39,6 +39,16 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) > return -1; > } > > +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) > +{ > + /* > + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when > + * the target task is stopped for tracing on entering syscall, so > + * there is no need to have the same check syscall_get_nr() has. > + */ > + regs->gpr[0] = nr; Doesn't the same as for ARM64 apply here as well ? > +} > + > static inline void syscall_rollback(struct task_struct *task, > struct pt_regs *regs) > {
On Tue, Jan 28, 2025 at 04:13:52PM +0100, Christophe Leroy wrote: > Le 28/01/2025 à 10:16, Dmitry V. Levin a écrit : > > Similar to syscall_set_arguments() that complements > > syscall_get_arguments(), introduce syscall_set_nr() > > that complements syscall_get_nr(). > > > > syscall_set_nr() is going to be needed along with > > syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK > > architectures to implement PTRACE_SET_SYSCALL_INFO API. > > > > Signed-off-by: Dmitry V. Levin <ldv@strace.io> > > Tested-by: Charlie Jenkins <charlie@rivosinc.com> > > Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> > > --- > > arch/arc/include/asm/syscall.h | 11 +++++++++++ > > arch/arm/include/asm/syscall.h | 24 ++++++++++++++++++++++++ > > arch/arm64/include/asm/syscall.h | 16 ++++++++++++++++ > > arch/hexagon/include/asm/syscall.h | 7 +++++++ > > arch/loongarch/include/asm/syscall.h | 7 +++++++ > > arch/m68k/include/asm/syscall.h | 7 +++++++ > > arch/microblaze/include/asm/syscall.h | 7 +++++++ > > arch/mips/include/asm/syscall.h | 14 ++++++++++++++ > > arch/nios2/include/asm/syscall.h | 5 +++++ > > arch/openrisc/include/asm/syscall.h | 6 ++++++ > > arch/parisc/include/asm/syscall.h | 7 +++++++ > > arch/powerpc/include/asm/syscall.h | 10 ++++++++++ > > arch/riscv/include/asm/syscall.h | 7 +++++++ > > arch/s390/include/asm/syscall.h | 12 ++++++++++++ > > arch/sh/include/asm/syscall_32.h | 12 ++++++++++++ > > arch/sparc/include/asm/syscall.h | 12 ++++++++++++ > > arch/um/include/asm/syscall-generic.h | 5 +++++ > > arch/x86/include/asm/syscall.h | 7 +++++++ > > arch/xtensa/include/asm/syscall.h | 7 +++++++ > > include/asm-generic/syscall.h | 14 ++++++++++++++ > > 20 files changed, 197 insertions(+) > > > > > diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h > > index 76020b66286b..712daa90e643 100644 > > --- a/arch/arm64/include/asm/syscall.h > > +++ b/arch/arm64/include/asm/syscall.h > > @@ -61,6 +61,22 @@ static inline void syscall_set_return_value(struct task_struct *task, > > regs->regs[0] = val; > > } > > > > +static inline void syscall_set_nr(struct task_struct *task, > > + struct pt_regs *regs, > > + int nr) > > +{ > > + regs->syscallno = nr; > > + if (nr == -1) { > > + /* > > + * When the syscall number is set to -1, the syscall will be > > + * skipped. In this case the syscall return value has to be > > + * set explicitly, otherwise the first syscall argument is > > + * returned as the syscall return value. > > + */ > > + syscall_set_return_value(task, regs, -ENOSYS, 0); > > + } > > +} > > + > > #define SYSCALL_MAX_ARGS 6 > > > > static inline void syscall_get_arguments(struct task_struct *task, > > > diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h > > index 521f279e6b33..7505dcfed247 100644 > > --- a/arch/powerpc/include/asm/syscall.h > > +++ b/arch/powerpc/include/asm/syscall.h > > @@ -39,6 +39,16 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) > > return -1; > > } > > > > +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) > > +{ > > + /* > > + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when > > + * the target task is stopped for tracing on entering syscall, so > > + * there is no need to have the same check syscall_get_nr() has. > > + */ > > + regs->gpr[0] = nr; > > Doesn't the same as for ARM64 apply here as well ? I carefully checked all affected architectures and added that syscall_set_return_value() call only where I think it's needed. On powerpc it's not needed with the current implementation: their do_seccomp() sets -ENOSYS before __secure_computing() invocation, and their do_syscall_trace_enter() sets -ENOSYS in case of an invalid syscall number.
diff --git a/arch/arc/include/asm/syscall.h b/arch/arc/include/asm/syscall.h index 89c1e1736356..728d625a10f1 100644 --- a/arch/arc/include/asm/syscall.h +++ b/arch/arc/include/asm/syscall.h @@ -23,6 +23,17 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return -1; } +static inline void +syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) +{ + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->r8 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h index 21927fa0ae2b..18b102a30741 100644 --- a/arch/arm/include/asm/syscall.h +++ b/arch/arm/include/asm/syscall.h @@ -68,6 +68,30 @@ static inline void syscall_set_return_value(struct task_struct *task, regs->ARM_r0 = (long) error ? error : val; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + if (nr == -1) { + task_thread_info(task)->abi_syscall = -1; + /* + * When the syscall number is set to -1, the syscall will be + * skipped. In this case the syscall return value has to be + * set explicitly, otherwise the first syscall argument is + * returned as the syscall return value. + */ + syscall_set_return_value(task, regs, -ENOSYS, 0); + return; + } + if ((IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT))) { + task_thread_info(task)->abi_syscall = nr; + return; + } + task_thread_info(task)->abi_syscall = + (task_thread_info(task)->abi_syscall & ~__NR_SYSCALL_MASK) | + (nr & __NR_SYSCALL_MASK); +} + #define SYSCALL_MAX_ARGS 7 static inline void syscall_get_arguments(struct task_struct *task, diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index 76020b66286b..712daa90e643 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -61,6 +61,22 @@ static inline void syscall_set_return_value(struct task_struct *task, regs->regs[0] = val; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->syscallno = nr; + if (nr == -1) { + /* + * When the syscall number is set to -1, the syscall will be + * skipped. In this case the syscall return value has to be + * set explicitly, otherwise the first syscall argument is + * returned as the syscall return value. + */ + syscall_set_return_value(task, regs, -ENOSYS, 0); + } +} + #define SYSCALL_MAX_ARGS 6 static inline void syscall_get_arguments(struct task_struct *task, diff --git a/arch/hexagon/include/asm/syscall.h b/arch/hexagon/include/asm/syscall.h index 1024a6548d78..70637261817a 100644 --- a/arch/hexagon/include/asm/syscall.h +++ b/arch/hexagon/include/asm/syscall.h @@ -26,6 +26,13 @@ static inline long syscall_get_nr(struct task_struct *task, return regs->r06; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->r06 = nr; +} + static inline void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, unsigned long *args) diff --git a/arch/loongarch/include/asm/syscall.h b/arch/loongarch/include/asm/syscall.h index ff415b3c0a8e..81d2733f7b94 100644 --- a/arch/loongarch/include/asm/syscall.h +++ b/arch/loongarch/include/asm/syscall.h @@ -26,6 +26,13 @@ static inline long syscall_get_nr(struct task_struct *task, return regs->regs[11]; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->regs[11] = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/m68k/include/asm/syscall.h b/arch/m68k/include/asm/syscall.h index d1453e850cdd..bf84b160c2eb 100644 --- a/arch/m68k/include/asm/syscall.h +++ b/arch/m68k/include/asm/syscall.h @@ -14,6 +14,13 @@ static inline int syscall_get_nr(struct task_struct *task, return regs->orig_d0; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->orig_d0 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/microblaze/include/asm/syscall.h b/arch/microblaze/include/asm/syscall.h index 5eb3f624cc59..b5b6b91fae3e 100644 --- a/arch/microblaze/include/asm/syscall.h +++ b/arch/microblaze/include/asm/syscall.h @@ -14,6 +14,13 @@ static inline long syscall_get_nr(struct task_struct *task, return regs->r12; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->r12 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h index 2dcc1d01b405..1cd25306cc13 100644 --- a/arch/mips/include/asm/syscall.h +++ b/arch/mips/include/asm/syscall.h @@ -41,6 +41,20 @@ static inline long syscall_get_nr(struct task_struct *task, return task_thread_info(task)->syscall; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + /* + * New syscall number has to be assigned to regs[2] because + * syscall_trace_entry() loads it from there unconditionally. + * + * Consequently, if the syscall was indirect and nr != __NR_syscall, + * then after this assignment the syscall will cease to be indirect. + */ + task_thread_info(task)->syscall = regs->regs[2] = nr; +} + static inline void mips_syscall_update_nr(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/nios2/include/asm/syscall.h b/arch/nios2/include/asm/syscall.h index 526449edd768..8e3eb1d689bb 100644 --- a/arch/nios2/include/asm/syscall.h +++ b/arch/nios2/include/asm/syscall.h @@ -15,6 +15,11 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return regs->r2; } +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) +{ + regs->r2 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/openrisc/include/asm/syscall.h b/arch/openrisc/include/asm/syscall.h index e6383be2a195..5e037d9659c5 100644 --- a/arch/openrisc/include/asm/syscall.h +++ b/arch/openrisc/include/asm/syscall.h @@ -25,6 +25,12 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return regs->orig_gpr11; } +static inline void +syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) +{ + regs->orig_gpr11 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/parisc/include/asm/syscall.h b/arch/parisc/include/asm/syscall.h index b146d0ae4c77..c11222798ab2 100644 --- a/arch/parisc/include/asm/syscall.h +++ b/arch/parisc/include/asm/syscall.h @@ -17,6 +17,13 @@ static inline long syscall_get_nr(struct task_struct *tsk, return regs->gr[20]; } +static inline void syscall_set_nr(struct task_struct *tsk, + struct pt_regs *regs, + int nr) +{ + regs->gr[20] = nr; +} + static inline void syscall_get_arguments(struct task_struct *tsk, struct pt_regs *regs, unsigned long *args) diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index 521f279e6b33..7505dcfed247 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h @@ -39,6 +39,16 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return -1; } +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) +{ + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->gpr[0] = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h index 8d389ba995c8..a5281cdf2b10 100644 --- a/arch/riscv/include/asm/syscall.h +++ b/arch/riscv/include/asm/syscall.h @@ -30,6 +30,13 @@ static inline int syscall_get_nr(struct task_struct *task, return regs->a7; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->a7 = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h index b3dd883699e7..12cd0c60c07b 100644 --- a/arch/s390/include/asm/syscall.h +++ b/arch/s390/include/asm/syscall.h @@ -24,6 +24,18 @@ static inline long syscall_get_nr(struct task_struct *task, (regs->int_code & 0xffff) : -1; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff); +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/sh/include/asm/syscall_32.h b/arch/sh/include/asm/syscall_32.h index cb51a7528384..7027d87d901d 100644 --- a/arch/sh/include/asm/syscall_32.h +++ b/arch/sh/include/asm/syscall_32.h @@ -15,6 +15,18 @@ static inline long syscall_get_nr(struct task_struct *task, return (regs->tra >= 0) ? regs->regs[3] : -1L; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->regs[3] = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/sparc/include/asm/syscall.h b/arch/sparc/include/asm/syscall.h index 62a5a78804c4..b0233924d323 100644 --- a/arch/sparc/include/asm/syscall.h +++ b/arch/sparc/include/asm/syscall.h @@ -25,6 +25,18 @@ static inline long syscall_get_nr(struct task_struct *task, return (syscall_p ? regs->u_regs[UREG_G1] : -1L); } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->u_regs[UREG_G1] = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h index 2984feb9d576..bcd73bcfe577 100644 --- a/arch/um/include/asm/syscall-generic.h +++ b/arch/um/include/asm/syscall-generic.h @@ -21,6 +21,11 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return PT_REGS_SYSCALL_NR(regs); } +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) +{ + PT_REGS_SYSCALL_NR(regs) = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index b9c249dd9e3d..c10dbb74cd00 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -38,6 +38,13 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) return regs->orig_ax; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->orig_ax = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h index f9a671cbf933..7db3b489c8ad 100644 --- a/arch/xtensa/include/asm/syscall.h +++ b/arch/xtensa/include/asm/syscall.h @@ -28,6 +28,13 @@ static inline long syscall_get_nr(struct task_struct *task, return regs->syscall; } +static inline void syscall_set_nr(struct task_struct *task, + struct pt_regs *regs, + int nr) +{ + regs->syscall = nr; +} + static inline void syscall_rollback(struct task_struct *task, struct pt_regs *regs) { diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h index 0f7b9a493de7..e33fd4e783c1 100644 --- a/include/asm-generic/syscall.h +++ b/include/asm-generic/syscall.h @@ -37,6 +37,20 @@ struct pt_regs; */ int syscall_get_nr(struct task_struct *task, struct pt_regs *regs); +/** + * syscall_set_nr - change the system call a task is executing + * @task: task of interest, must be blocked + * @regs: task_pt_regs() of @task + * @nr: system call number + * + * Changes the system call number @task is about to execute. + * + * It's only valid to call this when @task is stopped for tracing on + * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. + */ +void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr); + /** * syscall_rollback - roll back registers after an aborted system call * @task: task of interest, must be in system call exit tracing