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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-03 07:24:22 -1000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-03 07:24:22 -1000 |
commit | 2a80532c0745e140852e6b579bbe8371332bb45d (patch) | |
tree | 07dec9596c21e8ada353c571308ddb40889b156b /lib | |
parent | 00657bb3dbecee324336e1da1ad71b670b6aee60 (diff) | |
parent | 2966bd3698451a2172a57e7e97eebb4adbfc48a2 (diff) | |
download | lwn-2a80532c0745e140852e6b579bbe8371332bb45d.tar.gz lwn-2a80532c0745e140852e6b579bbe8371332bb45d.zip |
Merge tag 'printk-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Another preparation step for introducing printk kthreads. The main
piece is a per-console lock with several features:
- Support three priorities: normal, emergency, and panic. They will
be defined by a context where the lock is taken. A context with a
higher priority is allowed to take over the lock from a context
with a lower one.
The plan is to use the emergency context for Oops and WARN()
messages, and also by watchdogs.
The panic() context will be used on panic CPU.
- The owner might enter/exit regions where it is not safe to take
over the lock. It allows the take over the lock a safe way in the
middle of a message.
For example, serial drivers emit characters one by one. And the
serial port is in a safe state in between.
Only the final console_flush_in_panic() will be allowed to take
over the lock even in the unsafe state (last chance, pray, and
hope).
- A higher priority context might busy wait with a timeout. The
current owner is informed about the waiter and releases the lock
on exit from the unsafe state.
- The new lock is safe even in atomic contexts, including NMI.
Another change is a safe manipulation of per-console sequence number
counter under the new lock.
- simple_strntoull() micro-optimization
- Reduce pr_flush() pooling time.
- Calm down false warning about possible buffer invalid access to
console buffers when CONFIG_PRINTK is disabled.
[ .. and Thomas Gleixner wants to point out that while several of the
commits are attributed to him, he only authored the early versions of
said commits, and that John Ogness and Petr Mladek have been the ones
who sorted out the details and really should be those who get the
credit - Linus ]
* tag 'printk-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
vsprintf: uninline simple_strntoull(), reorder arguments
printk: printk: Remove unnecessary statements'len = 0;'
printk: Reduce pr_flush() pooling time
printk: fix illegal pbufs access for !CONFIG_PRINTK
printk: nbcon: Allow drivers to mark unsafe regions and check state
printk: nbcon: Add emit function and callback function for atomic printing
printk: nbcon: Add sequence handling
printk: nbcon: Add ownership state functions
printk: nbcon: Add buffer management
printk: Make static printk buffers available to nbcon
printk: nbcon: Add acquire/release logic
printk: Add non-BKL (nbcon) console basic infrastructure
Diffstat (limited to 'lib')
-rw-r--r-- | lib/vsprintf.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index afb88b24fa74..3e3733a7084f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -60,7 +60,8 @@ bool no_hash_pointers __ro_after_init; EXPORT_SYMBOL_GPL(no_hash_pointers); -static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base) +noinline +static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars) { const char *cp; unsigned long long result = 0ULL; @@ -95,7 +96,7 @@ static noinline unsigned long long simple_strntoull(const char *startp, size_t m noinline unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) { - return simple_strntoull(cp, INT_MAX, endp, base); + return simple_strntoull(cp, endp, base, INT_MAX); } EXPORT_SYMBOL(simple_strtoull); @@ -130,8 +131,8 @@ long simple_strtol(const char *cp, char **endp, unsigned int base) } EXPORT_SYMBOL(simple_strtol); -static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, - unsigned int base) +noinline +static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars) { /* * simple_strntoull() safely handles receiving max_chars==0 in the @@ -140,9 +141,9 @@ static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, * and the content of *cp is irrelevant. */ if (*cp == '-' && max_chars > 0) - return -simple_strntoull(cp + 1, max_chars - 1, endp, base); + return -simple_strntoull(cp + 1, endp, base, max_chars - 1); - return simple_strntoull(cp, max_chars, endp, base); + return simple_strntoull(cp, endp, base, max_chars); } /** @@ -155,7 +156,7 @@ static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, */ long long simple_strtoll(const char *cp, char **endp, unsigned int base) { - return simple_strntoll(cp, INT_MAX, endp, base); + return simple_strntoll(cp, endp, base, INT_MAX); } EXPORT_SYMBOL(simple_strtoll); @@ -3648,13 +3649,11 @@ int vsscanf(const char *buf, const char *fmt, va_list args) break; if (is_sign) - val.s = simple_strntoll(str, - field_width >= 0 ? field_width : INT_MAX, - &next, base); + val.s = simple_strntoll(str, &next, base, + field_width >= 0 ? field_width : INT_MAX); else - val.u = simple_strntoull(str, - field_width >= 0 ? field_width : INT_MAX, - &next, base); + val.u = simple_strntoull(str, &next, base, + field_width >= 0 ? field_width : INT_MAX); switch (qualifier) { case 'H': /* that's 'hh' in format */ |