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kcov: add prototypes for helper functions

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A number of internal functions in kcov are only called from generated code
and don't technically need a declaration, but 'make W=1' warns about
global symbols without a prototype:

kernel/kcov.c:199:14: error: no previous prototype for '__sanitizer_cov_trace_pc' [-Werror=missing-prototypes]
kernel/kcov.c:264:14: error: no previous prototype for '__sanitizer_cov_trace_cmp1' [-Werror=missing-prototypes]
kernel/kcov.c:270:14: error: no previous prototype for '__sanitizer_cov_trace_cmp2' [-Werror=missing-prototypes]
kernel/kcov.c:276:14: error: no previous prototype for '__sanitizer_cov_trace_cmp4' [-Werror=missing-prototypes]
kernel/kcov.c:282:14: error: no previous prototype for '__sanitizer_cov_trace_cmp8' [-Werror=missing-prototypes]
kernel/kcov.c:288:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp1' [-Werror=missing-prototypes]
kernel/kcov.c:295:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp2' [-Werror=missing-prototypes]
kernel/kcov.c:302:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp4' [-Werror=missing-prototypes]
kernel/kcov.c:309:14: error: no previous prototype for '__sanitizer_cov_trace_const_cmp8' [-Werror=missing-prototypes]
kernel/kcov.c:316:14: error: no previous prototype for '__sanitizer_cov_trace_switch' [-Werror=missing-prototypes]

Adding prototypes for these in a header solves that problem, but now there
is a mismatch between the built-in type and the prototype on 64-bit
architectures because they expect some functions to take a 64-bit
'unsigned long' argument rather than an 'unsigned long long' u64 type:

include/linux/kcov.h:84:6: error: conflicting types for built-in function '__sanitizer_cov_trace_switch'; expected 'void(long long unsigned int,  void *)' [-Werror=builtin-declaration-mismatch]
   84 | void __sanitizer_cov_trace_switch(u64 val, u64 *cases);
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Avoid this as well with a custom type definition.

Link: https://lkml.kernel.org/r/20230517124944.929997-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Arnd Bergmann 2023-05-17 14:49:25 +02:00 committed by Andrew Morton
parent 3403bb4ea5
commit e0ddec73fd
2 changed files with 21 additions and 3 deletions
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17
include/linux/kcov.h
View File

@ -72,6 +72,23 @@ static inline void kcov_remote_stop_softirq(void)
kcov_remote_stop();
}
#ifdef CONFIG_64BIT
typedef unsigned long kcov_u64;
#else
typedef unsigned long long kcov_u64;
#endif
void __sanitizer_cov_trace_pc(void);
void __sanitizer_cov_trace_cmp1(u8 arg1, u8 arg2);
void __sanitizer_cov_trace_cmp2(u16 arg1, u16 arg2);
void __sanitizer_cov_trace_cmp4(u32 arg1, u32 arg2);
void __sanitizer_cov_trace_cmp8(kcov_u64 arg1, kcov_u64 arg2);
void __sanitizer_cov_trace_const_cmp1(u8 arg1, u8 arg2);
void __sanitizer_cov_trace_const_cmp2(u16 arg1, u16 arg2);
void __sanitizer_cov_trace_const_cmp4(u32 arg1, u32 arg2);
void __sanitizer_cov_trace_const_cmp8(kcov_u64 arg1, kcov_u64 arg2);
void __sanitizer_cov_trace_switch(kcov_u64 val, void *cases);
#else
static inline void kcov_task_init(struct task_struct *t) {}

7
kernel/kcov.c
View File

@ -279,7 +279,7 @@ void notrace __sanitizer_cov_trace_cmp4(u32 arg1, u32 arg2)
}
EXPORT_SYMBOL(__sanitizer_cov_trace_cmp4);
void notrace __sanitizer_cov_trace_cmp8(u64 arg1, u64 arg2)
void notrace __sanitizer_cov_trace_cmp8(kcov_u64 arg1, kcov_u64 arg2)
{
write_comp_data(KCOV_CMP_SIZE(3), arg1, arg2, _RET_IP_);
}
@ -306,16 +306,17 @@ void notrace __sanitizer_cov_trace_const_cmp4(u32 arg1, u32 arg2)
}
EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp4);
void notrace __sanitizer_cov_trace_const_cmp8(u64 arg1, u64 arg2)
void notrace __sanitizer_cov_trace_const_cmp8(kcov_u64 arg1, kcov_u64 arg2)
{
write_comp_data(KCOV_CMP_SIZE(3) | KCOV_CMP_CONST, arg1, arg2,
_RET_IP_);
}
EXPORT_SYMBOL(__sanitizer_cov_trace_const_cmp8);
void notrace __sanitizer_cov_trace_switch(u64 val, u64 *cases)
void notrace __sanitizer_cov_trace_switch(kcov_u64 val, void *arg)
{
u64 i;
u64 *cases = arg;
u64 count = cases[0];
u64 size = cases[1];
u64 type = KCOV_CMP_CONST;