This series backports four commits to bring include/linux/overflow.h in line with v5.15.193: - 2541be80b1a2 ("overflow: Correct check_shl_overflow() comment") - 564e84663d25 ("compiler.h: drop fallback overflow checkers") - 1d1ac8244c22 ("overflow: Allow mixed type arguments") - f96cfe3e05b0 ("tracing: Define the is_signed_type() macro once")
The motivation is to fix build failures such as:
drivers/net/ethernet/intel/e1000e/ethtool.c: In function ‘e1000_set_eeprom’: ./include/linux/overflow.h:71:15: error: comparison of distinct pointer types lacks a cast [-Werror] 71 | (void) (&__a == __d); \ | ^~ drivers/net/ethernet/intel/e1000e/ethtool.c:582:6: note: in expansion of macro ‘check_add_overflow’ 582 | if (check_add_overflow(eeprom->offset, eeprom->len, &total_len) || | ^~~~~~~~~~~~~~~~~~
This regression was triggered by commit ce8829d3d44b ("e1000e: fix heap overflow in e1000_set_eeprom").
check_add_overflow() requires the first two operands and the result pointer to be of identical type. On 64-bit builds, using size_t for the result conflicted with the u32 fields eeprom->offset and eeprom->len, resulting in type check failures.
BarteVan Assche (1): tracing: Define the is_signed_type() macro once
Kees Cook (1): overflow: Allow mixed type arguments
Keith Busch (1): overflow: Correct check_shl_overflow() comment
Nick Desaulniers (1): compiler.h: drop fallback overflow checkers
include/linux/compiler-clang.h | 13 -- include/linux/compiler-gcc.h | 4 - include/linux/compiler.h | 6 + include/linux/overflow.h | 209 ++++++----------------------- include/linux/trace_events.h | 2 - tools/include/linux/compiler-gcc.h | 4 - tools/include/linux/overflow.h | 140 +------------------ 7 files changed, 52 insertions(+), 326 deletions(-)
From: Keith Busch kbusch@kernel.org
[ Upstream commit 4578be130a6470d85ff05b13b75a00e6224eeeeb ]
A 'false' return means the value was safely set, so the comment should say 'true' for when it is not considered safe.
Cc: Jason Gunthorpe jgg@ziepe.ca Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Kees Cook keescook@chromium.org Fixes: 0c66847793d1 ("overflow.h: Add arithmetic shift helper") Link: https://lore.kernel.org/r/20210401160629.1941787-1-kbusch@kernel.org --- include/linux/overflow.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 35af574d006f..d1dd039fe1c3 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -235,7 +235,7 @@ static inline bool __must_check __must_check_overflow(bool overflow) * - 'a << s' sets the sign bit, if any, in '*d'. * * '*d' will hold the results of the attempted shift, but is not - * considered "safe for use" if false is returned. + * considered "safe for use" if true is returned. */ #define check_shl_overflow(a, s, d) __must_check_overflow(({ \ typeof(a) _a = a; \
From: Nick Desaulniers ndesaulniers@google.com
[ Upstream commit 4eb6bd55cfb22ffc20652732340c4962f3ac9a91 ]
Once upgrading the minimum supported version of GCC to 5.1, we can drop the fallback code for !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW.
This is effectively a revert of commit f0907827a8a9 ("compiler.h: enable builtin overflow checkers and add fallback code")
Link: https://github.com/ClangBuiltLinux/linux/issues/1438#issuecomment-916745801 Suggested-by: Rasmus Villemoes linux@rasmusvillemoes.dk Signed-off-by: Nick Desaulniers ndesaulniers@google.com Acked-by: Kees Cook keescook@chromium.org Reviewed-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org --- include/linux/compiler-clang.h | 13 --- include/linux/compiler-gcc.h | 4 - include/linux/overflow.h | 138 +--------------------------- tools/include/linux/compiler-gcc.h | 4 - tools/include/linux/overflow.h | 140 +---------------------------- 5 files changed, 6 insertions(+), 293 deletions(-)
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 9ba951e3a6c2..928ec5c7776d 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -72,19 +72,6 @@ #define __no_sanitize_coverage #endif
-/* - * Not all versions of clang implement the type-generic versions - * of the builtin overflow checkers. Fortunately, clang implements - * __has_builtin allowing us to avoid awkward version - * checks. Unfortunately, we don't know which version of gcc clang - * pretends to be, so the macro may or may not be defined. - */ -#if __has_builtin(__builtin_mul_overflow) && \ - __has_builtin(__builtin_add_overflow) && \ - __has_builtin(__builtin_sub_overflow) -#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 -#endif - #if __has_feature(shadow_call_stack) # define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) #endif diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 5b481a22b5fe..ae9a8e17287c 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -140,10 +140,6 @@ #define __no_sanitize_coverage #endif
-#if GCC_VERSION >= 50100 -#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 -#endif - /* * Turn individual warnings and errors on and off locally, depending * on version. diff --git a/include/linux/overflow.h b/include/linux/overflow.h index d1dd039fe1c3..59d7228104d0 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -6,12 +6,9 @@ #include <linux/limits.h>
/* - * In the fallback code below, we need to compute the minimum and - * maximum values representable in a given type. These macros may also - * be useful elsewhere, so we provide them outside the - * COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block. - * - * It would seem more obvious to do something like + * We need to compute the minimum and maximum values representable in a given + * type. These macros may also be useful elsewhere. It would seem more obvious + * to do something like: * * #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0) * #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0) @@ -54,7 +51,6 @@ static inline bool __must_check __must_check_overflow(bool overflow) return unlikely(overflow); }
-#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW /* * For simplicity and code hygiene, the fallback code below insists on * a, b and *d having the same type (similar to the min() and max() @@ -90,134 +86,6 @@ static inline bool __must_check __must_check_overflow(bool overflow) __builtin_mul_overflow(__a, __b, __d); \ }))
-#else - - -/* Checking for unsigned overflow is relatively easy without causing UB. */ -#define __unsigned_add_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a + __b; \ - *__d < __a; \ -}) -#define __unsigned_sub_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a - __b; \ - __a < __b; \ -}) -/* - * If one of a or b is a compile-time constant, this avoids a division. - */ -#define __unsigned_mul_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a * __b; \ - __builtin_constant_p(__b) ? \ - __b > 0 && __a > type_max(typeof(__a)) / __b : \ - __a > 0 && __b > type_max(typeof(__b)) / __a; \ -}) - -/* - * For signed types, detecting overflow is much harder, especially if - * we want to avoid UB. But the interface of these macros is such that - * we must provide a result in *d, and in fact we must produce the - * result promised by gcc's builtins, which is simply the possibly - * wrapped-around value. Fortunately, we can just formally do the - * operations in the widest relevant unsigned type (u64) and then - * truncate the result - gcc is smart enough to generate the same code - * with and without the (u64) casts. - */ - -/* - * Adding two signed integers can overflow only if they have the same - * sign, and overflow has happened iff the result has the opposite - * sign. - */ -#define __signed_add_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a + (u64)__b; \ - (((~(__a ^ __b)) & (*__d ^ __a)) \ - & type_min(typeof(__a))) != 0; \ -}) - -/* - * Subtraction is similar, except that overflow can now happen only - * when the signs are opposite. In this case, overflow has happened if - * the result has the opposite sign of a. - */ -#define __signed_sub_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a - (u64)__b; \ - ((((__a ^ __b)) & (*__d ^ __a)) \ - & type_min(typeof(__a))) != 0; \ -}) - -/* - * Signed multiplication is rather hard. gcc always follows C99, so - * division is truncated towards 0. This means that we can write the - * overflow check like this: - * - * (a > 0 && (b > MAX/a || b < MIN/a)) || - * (a < -1 && (b > MIN/a || b < MAX/a) || - * (a == -1 && b == MIN) - * - * The redundant casts of -1 are to silence an annoying -Wtype-limits - * (included in -Wextra) warning: When the type is u8 or u16, the - * __b_c_e in check_mul_overflow obviously selects - * __unsigned_mul_overflow, but unfortunately gcc still parses this - * code and warns about the limited range of __b. - */ - -#define __signed_mul_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - typeof(a) __tmax = type_max(typeof(a)); \ - typeof(a) __tmin = type_min(typeof(a)); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a * (u64)__b; \ - (__b > 0 && (__a > __tmax/__b || __a < __tmin/__b)) || \ - (__b < (typeof(__b))-1 && (__a > __tmin/__b || __a < __tmax/__b)) || \ - (__b == (typeof(__b))-1 && __a == __tmin); \ -}) - - -#define check_add_overflow(a, b, d) __must_check_overflow( \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_add_overflow(a, b, d), \ - __unsigned_add_overflow(a, b, d))) - -#define check_sub_overflow(a, b, d) __must_check_overflow( \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_sub_overflow(a, b, d), \ - __unsigned_sub_overflow(a, b, d))) - -#define check_mul_overflow(a, b, d) __must_check_overflow( \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_mul_overflow(a, b, d), \ - __unsigned_mul_overflow(a, b, d))) - -#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */ - /** check_shl_overflow() - Calculate a left-shifted value and check overflow * * @a: Value to be shifted diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h index 95c072b70d0e..a590a1dfafd9 100644 --- a/tools/include/linux/compiler-gcc.h +++ b/tools/include/linux/compiler-gcc.h @@ -38,7 +38,3 @@ #endif #define __printf(a, b) __attribute__((format(printf, a, b))) #define __scanf(a, b) __attribute__((format(scanf, a, b))) - -#if GCC_VERSION >= 50100 -#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 -#endif diff --git a/tools/include/linux/overflow.h b/tools/include/linux/overflow.h index 8712ff70995f..dcb0c1bf6866 100644 --- a/tools/include/linux/overflow.h +++ b/tools/include/linux/overflow.h @@ -5,12 +5,9 @@ #include <linux/compiler.h>
/* - * In the fallback code below, we need to compute the minimum and - * maximum values representable in a given type. These macros may also - * be useful elsewhere, so we provide them outside the - * COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block. - * - * It would seem more obvious to do something like + * We need to compute the minimum and maximum values representable in a given + * type. These macros may also be useful elsewhere. It would seem more obvious + * to do something like: * * #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0) * #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0) @@ -36,8 +33,6 @@ #define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T))) #define type_min(T) ((T)((T)-type_max(T)-(T)1))
- -#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW /* * For simplicity and code hygiene, the fallback code below insists on * a, b and *d having the same type (similar to the min() and max() @@ -73,135 +68,6 @@ __builtin_mul_overflow(__a, __b, __d); \ })
-#else - - -/* Checking for unsigned overflow is relatively easy without causing UB. */ -#define __unsigned_add_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a + __b; \ - *__d < __a; \ -}) -#define __unsigned_sub_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a - __b; \ - __a < __b; \ -}) -/* - * If one of a or b is a compile-time constant, this avoids a division. - */ -#define __unsigned_mul_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = __a * __b; \ - __builtin_constant_p(__b) ? \ - __b > 0 && __a > type_max(typeof(__a)) / __b : \ - __a > 0 && __b > type_max(typeof(__b)) / __a; \ -}) - -/* - * For signed types, detecting overflow is much harder, especially if - * we want to avoid UB. But the interface of these macros is such that - * we must provide a result in *d, and in fact we must produce the - * result promised by gcc's builtins, which is simply the possibly - * wrapped-around value. Fortunately, we can just formally do the - * operations in the widest relevant unsigned type (u64) and then - * truncate the result - gcc is smart enough to generate the same code - * with and without the (u64) casts. - */ - -/* - * Adding two signed integers can overflow only if they have the same - * sign, and overflow has happened iff the result has the opposite - * sign. - */ -#define __signed_add_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a + (u64)__b; \ - (((~(__a ^ __b)) & (*__d ^ __a)) \ - & type_min(typeof(__a))) != 0; \ -}) - -/* - * Subtraction is similar, except that overflow can now happen only - * when the signs are opposite. In this case, overflow has happened if - * the result has the opposite sign of a. - */ -#define __signed_sub_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a - (u64)__b; \ - ((((__a ^ __b)) & (*__d ^ __a)) \ - & type_min(typeof(__a))) != 0; \ -}) - -/* - * Signed multiplication is rather hard. gcc always follows C99, so - * division is truncated towards 0. This means that we can write the - * overflow check like this: - * - * (a > 0 && (b > MAX/a || b < MIN/a)) || - * (a < -1 && (b > MIN/a || b < MAX/a) || - * (a == -1 && b == MIN) - * - * The redundant casts of -1 are to silence an annoying -Wtype-limits - * (included in -Wextra) warning: When the type is u8 or u16, the - * __b_c_e in check_mul_overflow obviously selects - * __unsigned_mul_overflow, but unfortunately gcc still parses this - * code and warns about the limited range of __b. - */ - -#define __signed_mul_overflow(a, b, d) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - typeof(a) __tmax = type_max(typeof(a)); \ - typeof(a) __tmin = type_min(typeof(a)); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - *__d = (u64)__a * (u64)__b; \ - (__b > 0 && (__a > __tmax/__b || __a < __tmin/__b)) || \ - (__b < (typeof(__b))-1 && (__a > __tmin/__b || __a < __tmax/__b)) || \ - (__b == (typeof(__b))-1 && __a == __tmin); \ -}) - - -#define check_add_overflow(a, b, d) \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_add_overflow(a, b, d), \ - __unsigned_add_overflow(a, b, d)) - -#define check_sub_overflow(a, b, d) \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_sub_overflow(a, b, d), \ - __unsigned_sub_overflow(a, b, d)) - -#define check_mul_overflow(a, b, d) \ - __builtin_choose_expr(is_signed_type(typeof(a)), \ - __signed_mul_overflow(a, b, d), \ - __unsigned_mul_overflow(a, b, d)) - - -#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */ - /** * array_size() - Calculate size of 2-dimensional array. *
From: Kees Cook keescook@chromium.org
commit d219d2a9a92e39aa92799efe8f2aa21259b6dd82 upstream.
When the check_[op]_overflow() helpers were introduced, all arguments were required to be the same type to make the fallback macros simpler. However, now that the fallback macros have been removed[1], it is fine to allow mixed types, which makes using the helpers much more useful, as they can be used to test for type-based overflows (e.g. adding two large ints but storing into a u8), as would be handy in the drm core[2].
Remove the restriction, and add additional self-tests that exercise some of the mixed-type overflow cases, and double-check for accidental macro side-effects.
[1] https://git.kernel.org/linus/4eb6bd55cfb22ffc20652732340c4962f3ac9a91 [2] https://lore.kernel.org/lkml/20220824084514.2261614-2-gwan-gyeong.mun@intel....
Cc: Rasmus Villemoes linux@rasmusvillemoes.dk Cc: Gwan-gyeong Mun gwan-gyeong.mun@intel.com Cc: "Gustavo A. R. Silva" gustavoars@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: linux-hardening@vger.kernel.org Reviewed-by: Andrzej Hajda andrzej.hajda@intel.com Reviewed-by: Gwan-gyeong Mun gwan-gyeong.mun@intel.com Tested-by: Gwan-gyeong Mun gwan-gyeong.mun@intel.com Signed-off-by: Kees Cook keescook@chromium.org [ dropped the test portion of the commit as that doesn't apply to 5.15.y - gregkh] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/overflow.h | 72 +++++++++++++++++++++++----------------- 1 file changed, 41 insertions(+), 31 deletions(-)
diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 59d7228104d0..73bc67ec2136 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -51,40 +51,50 @@ static inline bool __must_check __must_check_overflow(bool overflow) return unlikely(overflow); }
-/* - * For simplicity and code hygiene, the fallback code below insists on - * a, b and *d having the same type (similar to the min() and max() - * macros), whereas gcc's type-generic overflow checkers accept - * different types. Hence we don't just make check_add_overflow an - * alias for __builtin_add_overflow, but add type checks similar to - * below. +/** check_add_overflow() - Calculate addition with overflow checking + * + * @a: first addend + * @b: second addend + * @d: pointer to store sum + * + * Returns 0 on success. + * + * *@d holds the results of the attempted addition, but is not considered + * "safe for use" on a non-zero return value, which indicates that the + * sum has overflowed or been truncated. */ -#define check_add_overflow(a, b, d) __must_check_overflow(({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - __builtin_add_overflow(__a, __b, __d); \ -})) +#define check_add_overflow(a, b, d) \ + __must_check_overflow(__builtin_add_overflow(a, b, d))
-#define check_sub_overflow(a, b, d) __must_check_overflow(({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - __builtin_sub_overflow(__a, __b, __d); \ -})) +/** check_sub_overflow() - Calculate subtraction with overflow checking + * + * @a: minuend; value to subtract from + * @b: subtrahend; value to subtract from @a + * @d: pointer to store difference + * + * Returns 0 on success. + * + * *@d holds the results of the attempted subtraction, but is not considered + * "safe for use" on a non-zero return value, which indicates that the + * difference has underflowed or been truncated. + */ +#define check_sub_overflow(a, b, d) \ + __must_check_overflow(__builtin_sub_overflow(a, b, d))
-#define check_mul_overflow(a, b, d) __must_check_overflow(({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - typeof(d) __d = (d); \ - (void) (&__a == &__b); \ - (void) (&__a == __d); \ - __builtin_mul_overflow(__a, __b, __d); \ -})) +/** check_mul_overflow() - Calculate multiplication with overflow checking + * + * @a: first factor + * @b: second factor + * @d: pointer to store product + * + * Returns 0 on success. + * + * *@d holds the results of the attempted multiplication, but is not + * considered "safe for use" on a non-zero return value, which indicates + * that the product has overflowed or been truncated. + */ +#define check_mul_overflow(a, b, d) \ + __must_check_overflow(__builtin_mul_overflow(a, b, d))
/** check_shl_overflow() - Calculate a left-shifted value and check overflow *
From: Bart Van Assche bvanassche@acm.org
commit a49a64b5bf195381c09202c524f0f84b5f3e816f upstream.
There are two definitions of the is_signed_type() macro: one in <linux/overflow.h> and a second definition in <linux/trace_events.h>.
As suggested by Linus, move the definition of the is_signed_type() macro into the <linux/compiler.h> header file. Change the definition of the is_signed_type() macro to make sure that it does not trigger any sparse warnings with future versions of sparse for bitwise types.
Link: https://lore.kernel.org/all/CAHk-=whjH6p+qzwUdx5SOVVHjS3WvzJQr6mDUwhEyTf6pJW... Link: https://lore.kernel.org/all/CAHk-=wjQGnVfb4jehFR0XyZikdQvCZouE96xR_nnf5kqaM5... Cc: Rasmus Villemoes linux@rasmusvillemoes.dk Cc: Steven Rostedt rostedt@goodmis.org Acked-by: Kees Cook keescook@chromium.org Signed-off-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org (cherry picked from commit a49a64b5bf195381c09202c524f0f84b5f3e816f) Signed-off-by: SeongJae Park sj@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/compiler.h | 6 ++++++ include/linux/overflow.h | 1 - include/linux/trace_events.h | 2 -- 3 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index bbd74420fa21..004a030d5ad2 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -245,6 +245,12 @@ static inline void *offset_to_ptr(const int *off) /* &a[0] degrades to a pointer: a different type from an array */ #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
+/* + * Whether 'type' is a signed type or an unsigned type. Supports scalar types, + * bool and also pointer types. + */ +#define is_signed_type(type) (((type)(-1)) < (__force type)1) + /* * This is needed in functions which generate the stack canary, see * arch/x86/kernel/smpboot.c::start_secondary() for an example. diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 73bc67ec2136..e6bf14f462e9 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -29,7 +29,6 @@ * https://mail-index.netbsd.org/tech-misc/2007/02/05/0000.html - * credit to Christian Biere. */ -#define is_signed_type(type) (((type)(-1)) < (type)1) #define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type))) #define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T))) #define type_min(T) ((T)((T)-type_max(T)-(T)1)) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 5af2acb9fb7d..0c8c3cf36f96 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -700,8 +700,6 @@ extern int trace_add_event_call(struct trace_event_call *call); extern int trace_remove_event_call(struct trace_event_call *call); extern int trace_event_get_offsets(struct trace_event_call *call);
-#define is_signed_type(type) (((type)(-1)) < (type)1) - int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); int trace_set_clr_event(const char *system, const char *event, int set); int trace_array_set_clr_event(struct trace_array *tr, const char *system,
On Fri, Sep 12, 2025 at 12:56:01PM +0000, Eliav Farber wrote:
This series backports four commits to bring include/linux/overflow.h in line with v5.15.193:
- 2541be80b1a2 ("overflow: Correct check_shl_overflow() comment")
- 564e84663d25 ("compiler.h: drop fallback overflow checkers")
- 1d1ac8244c22 ("overflow: Allow mixed type arguments")
- f96cfe3e05b0 ("tracing: Define the is_signed_type() macro once")
You forgot to sign-off on these backports :(
Other than that, they look good to me, thanks! Can you resend with that added?
thanks,
greg k-h
On Fri, Sep 12, 2025 at 12:56:01PM +0000, Eliav Farber wrote:
This series backports four commits to bring include/linux/overflow.h in line with v5.15.193:
- 2541be80b1a2 ("overflow: Correct check_shl_overflow() comment")
- 564e84663d25 ("compiler.h: drop fallback overflow checkers")
- 1d1ac8244c22 ("overflow: Allow mixed type arguments")
- f96cfe3e05b0 ("tracing: Define the is_signed_type() macro once")
You forgot to sign-off on these backports :(
Other than that, they look good to me, thanks! Can you resend with that added?
Done
--- Thanks, Eliav
linux-stable-mirror@lists.linaro.org
-
Eliav Farber -
Farber, Eliav
-
Greg KH