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/* SPDX-License-Identifier: GPL-2.0-only */
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/*
* Copyright ( C ) 2012 ARM Ltd .
*/
# ifndef __ASM_SYSCALL_H
# define __ASM_SYSCALL_H
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# include <uapi/linux/audit.h>
# include <linux/compat.h>
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# include <linux/err.h>
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typedef long ( * syscall_fn_t ) ( const struct pt_regs * regs ) ;
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extern const syscall_fn_t sys_call_table [ ] ;
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# ifdef CONFIG_COMPAT
extern const syscall_fn_t compat_sys_call_table [ ] ;
# endif
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static inline int syscall_get_nr ( struct task_struct * task ,
struct pt_regs * regs )
{
return regs - > syscallno ;
}
static inline void syscall_rollback ( struct task_struct * task ,
struct pt_regs * regs )
{
regs - > regs [ 0 ] = regs - > orig_x0 ;
}
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
static inline long syscall_get_return_value ( struct task_struct * task ,
struct pt_regs * regs )
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{
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
unsigned long val = regs - > regs [ 0 ] ;
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if ( is_compat_thread ( task_thread_info ( task ) ) )
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
val = sign_extend64 ( val , 31 ) ;
2020-07-03 12:08:42 +01:00
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
return val ;
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}
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
static inline long syscall_get_error ( struct task_struct * task ,
struct pt_regs * regs )
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{
arm64: fix compat syscall return truncation
Due to inconsistencies in the way we manipulate compat GPRs, we have a
few issues today:
* For audit and tracing, where error codes are handled as a (native)
long, negative error codes are expected to be sign-extended to the
native 64-bits, or they may fail to be matched correctly. Thus a
syscall which fails with an error may erroneously be identified as
failing.
* For ptrace, *all* compat return values should be sign-extended for
consistency with 32-bit arm, but we currently only do this for
negative return codes.
* As we may transiently set the upper 32 bits of some compat GPRs while
in the kernel, these can be sampled by perf, which is somewhat
confusing. This means that where a syscall returns a pointer above 2G,
this will be sign-extended, but will not be mistaken for an error as
error codes are constrained to the inclusive range [-4096, -1] where
no user pointer can exist.
To fix all of these, we must consistently use helpers to get/set the
compat GPRs, ensuring that we never write the upper 32 bits of the
return code, and always sign-extend when reading the return code. This
patch does so, with the following changes:
* We re-organise syscall_get_return_value() to always sign-extend for
compat tasks, and reimplement syscall_get_error() atop. We update
syscall_trace_exit() to use syscall_get_return_value().
* We consistently use syscall_set_return_value() to set the return
value, ensureing the upper 32 bits are never set unexpectedly.
* As the core audit code currently uses regs_return_value() rather than
syscall_get_return_value(), we special-case this for
compat_user_mode(regs) such that this will do the right thing. Going
forward, we should try to move the core audit code over to
syscall_get_return_value().
Cc: <stable@vger.kernel.org>
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: weiyuchen <weiyuchen3@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210802104200.21390-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-08-02 11:42:00 +01:00
unsigned long error = syscall_get_return_value ( task , regs ) ;
return IS_ERR_VALUE ( error ) ? error : 0 ;
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}
static inline void syscall_set_return_value ( struct task_struct * task ,
struct pt_regs * regs ,
int error , long val )
{
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if ( error )
val = error ;
if ( is_compat_thread ( task_thread_info ( task ) ) )
val = lower_32_bits ( val ) ;
regs - > regs [ 0 ] = val ;
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}
# define SYSCALL_MAX_ARGS 6
static inline void syscall_get_arguments ( struct task_struct * task ,
struct pt_regs * regs ,
unsigned long * args )
{
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args [ 0 ] = regs - > orig_x0 ;
args + + ;
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memcpy ( args , & regs - > regs [ 1 ] , 5 * sizeof ( args [ 0 ] ) ) ;
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}
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/*
* We don ' t care about endianness ( __AUDIT_ARCH_LE bit ) here because
* AArch64 has the same system calls both on little - and big - endian .
*/
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static inline int syscall_get_arch ( struct task_struct * task )
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{
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if ( is_compat_thread ( task_thread_info ( task ) ) )
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return AUDIT_ARCH_ARM ;
return AUDIT_ARCH_AARCH64 ;
}
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# endif /* __ASM_SYSCALL_H */
