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| author | Sven Schnelle <svens@linux.ibm.com> | 2026-09-09 11:29:53 +0200 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-09-10 08:43:35 +0900 |
| commit | d22c3e0088e85be8131f7a9283f759cdbb20726d (patch) | |
| tree | 9668df2aa27b26f850d3ba5ba1287e443803675c /include/asm-generic/delay.h | |
| download | linux-stable-d22c3e0088e85be8131f7a9283f759cdbb20726d.tar.gz linux-stable-d22c3e0088e85be8131f7a9283f759cdbb20726d.zip | |
selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tcgrafted
The current regex also matches symbols in modules, which makes the
test fail on s390 where name_show is present only once in the kernel,
but also multiple times in modules:
000001b1401cdc20 t name_show
000001b0c05e6c40 t name_show [mdev]
000001b0c0495f30 t name_show [i2c_core]
Fix this by changing the regular expression to only match the function
name.
Link: https://lore.kernel.org/all/20260909092954.2200558-1-svens@linux.ibm.com/
Fixes: 03b80ff8023a ("selftests/ftrace: Add new test case which checks non unique symbol")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'include/asm-generic/delay.h')
| -rw-r--r-- | include/asm-generic/delay.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h new file mode 100644 index 000000000..03b0ec7af --- /dev/null +++ b/include/asm-generic/delay.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_DELAY_H +#define __ASM_GENERIC_DELAY_H + +#include <linux/math.h> +#include <vdso/time64.h> + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern void __udelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); +extern void __const_udelay(unsigned long xloops); +extern void __delay(unsigned long loops); + +/* + * The microseconds/nanosecond delay multiplicators are used to convert a + * constant microseconds/nanoseconds value to a value which can be used by the + * architectures specific implementation to transform it into loops. + */ +#define UDELAY_CONST_MULT ((unsigned long)DIV_ROUND_UP(1ULL << 32, USEC_PER_SEC)) +#define NDELAY_CONST_MULT ((unsigned long)DIV_ROUND_UP(1ULL << 32, NSEC_PER_SEC)) + +/* + * The maximum constant udelay/ndelay value picked out of thin air to prevent + * too long constant udelays/ndelays. + */ +#define DELAY_CONST_MAX 20000 + +/** + * udelay - Inserting a delay based on microseconds with busy waiting + * @usec: requested delay in microseconds + * + * When delaying in an atomic context ndelay(), udelay() and mdelay() are the + * only valid variants of delaying/sleeping to go with. + * + * When inserting delays in non atomic context which are shorter than the time + * which is required to queue e.g. an hrtimer and to enter then the scheduler, + * it is also valuable to use udelay(). But it is not simple to specify a + * generic threshold for this which will fit for all systems. An approximation + * is a threshold for all delays up to 10 microseconds. + * + * When having a delay which is larger than the architecture specific + * %MAX_UDELAY_MS value, please make sure mdelay() is used. Otherwise a overflow + * risk is given. + * + * Please note that ndelay(), udelay() and mdelay() may return early for several + * reasons (https://lists.openwall.net/linux-kernel/2011/01/09/56): + * + * #. computed loops_per_jiffy too low (due to the time taken to execute the + * timer interrupt.) + * #. cache behaviour affecting the time it takes to execute the loop function. + * #. CPU clock rate changes. + */ +static __always_inline void udelay(unsigned long usec) +{ + if (__builtin_constant_p(usec)) { + if (usec >= DELAY_CONST_MAX) + __bad_udelay(); + else + __const_udelay(usec * UDELAY_CONST_MULT); + } else { + __udelay(usec); + } +} + +/** + * ndelay - Inserting a delay based on nanoseconds with busy waiting + * @nsec: requested delay in nanoseconds + * + * See udelay() for basic information about ndelay() and it's variants. + */ +static __always_inline void ndelay(unsigned long nsec) +{ + if (__builtin_constant_p(nsec)) { + if (nsec >= DELAY_CONST_MAX) + __bad_ndelay(); + else + __const_udelay(nsec * NDELAY_CONST_MULT); + } else { + __ndelay(nsec); + } +} +#define ndelay(x) ndelay(x) + +#endif /* __ASM_GENERIC_DELAY_H */ |
