From: Sunil Dora Date: Tue, 14 Oct 2025 14:43:39 +0000 (-0700) Subject: glibc: nptl Update comments and indentation for new condvar implementation X-Git-Tag: yocto-4.0.31~21 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bf3d91124c2584b9d3000098d1f81d9459d143fc;p=thirdparty%2Fopenembedded%2Fopenembedded-core.git glibc: nptl Update comments and indentation for new condvar implementation The following commits have been cherry-picked from Glibc master branch: Bug : https://sourceware.org/bugzilla/show_bug.cgi?id=25847 [1] https://sourceware.org/git/?p=glibc.git;a=commit;h=0cc973160c23bb67f895bc887dd6942d29f8fee3 [2] https://sourceware.org/pipermail/libc-stable/2025-July/002275.html Signed-off-by: Sunil Dora Signed-off-by: Steve Sakoman --- diff --git a/meta/recipes-core/glibc/glibc/0026-PR25847-2.patch b/meta/recipes-core/glibc/glibc/0026-PR25847-2.patch new file mode 100644 index 0000000000..a9ed702170 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0026-PR25847-2.patch @@ -0,0 +1,145 @@ +From 306ea7810f5f6709ef3942a7be75077203b5d201 Mon Sep 17 00:00:00 2001 +From: Malte Skarupke +Date: Tue, 14 Oct 2025 04:27:19 -0700 +Subject: [PATCH] nptl: Update comments and indentation for new condvar + implementation + +Some comments were wrong after the most recent commit. This fixes that. +Also fixing indentation where it was using spaces instead of tabs. + +The following commits have been cherry-picked from Glibc master branch: +Bug : https://sourceware.org/bugzilla/show_bug.cgi?id=25847 +commit: 0cc973160c23bb67f895bc887dd6942d29f8fee3 + +Upstream-Status: Submitted +[https://sourceware.org/pipermail/libc-stable/2025-July/002275.html] + +Signed-off-by: Sunil Dora +--- + nptl/pthread_cond_common.c | 5 +++-- + nptl/pthread_cond_wait.c | 39 +++++++++++++++++++------------------- + 2 files changed, 22 insertions(+), 22 deletions(-) + +diff --git a/nptl/pthread_cond_common.c b/nptl/pthread_cond_common.c +index a55eee3e..350a16fa 100644 +--- a/nptl/pthread_cond_common.c ++++ b/nptl/pthread_cond_common.c +@@ -221,8 +221,9 @@ __condvar_quiesce_and_switch_g1 (pthread_cond_t *cond, uint64_t wseq, + * New waiters arriving concurrently with the group switching will all go + into G2 until we atomically make the switch. Waiters existing in G2 + are not affected. +- * Waiters in G1 will be closed out immediately by the advancing of +- __g_signals to the next "lowseq" (low 31 bits of the new g1_start), ++ * Waiters in G1 have already received a signal and been woken. If they ++ haven't woken yet, they will be closed out immediately by the advancing ++ of __g_signals to the next "lowseq" (low 31 bits of the new g1_start), + which will prevent waiters from blocking using a futex on + __g_signals since it provides enough signals for all possible + remaining waiters. As a result, they can each consume a signal +diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c +index 1cb3dbf7..cee19687 100644 +--- a/nptl/pthread_cond_wait.c ++++ b/nptl/pthread_cond_wait.c +@@ -249,7 +249,7 @@ __condvar_cleanup_waiting (void *arg) + figure out whether they are in a group that has already been completely + signaled (i.e., if the current G1 starts at a later position that the + waiter's position). Waiters cannot determine whether they are currently +- in G2 or G1 -- but they do not have too because all they are interested in ++ in G2 or G1 -- but they do not have to because all they are interested in + is whether there are available signals, and they always start in G2 (whose + group slot they know because of the bit in the waiter sequence. Signalers + will simply fill the right group until it is completely signaled and can +@@ -412,7 +412,7 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, + } + + /* Now wait until a signal is available in our group or it is closed. +- Acquire MO so that if we observe a value of zero written after group ++ Acquire MO so that if we observe (signals == lowseq) after group + switching in __condvar_quiesce_and_switch_g1, we synchronize with that + store and will see the prior update of __g1_start done while switching + groups too. */ +@@ -422,8 +422,8 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, + { + while (1) + { +- uint64_t g1_start = __condvar_load_g1_start_relaxed (cond); +- unsigned int lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; ++ uint64_t g1_start = __condvar_load_g1_start_relaxed (cond); ++ unsigned int lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; + + /* Spin-wait first. + Note that spinning first without checking whether a timeout +@@ -447,21 +447,21 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, + + /* Reload signals. See above for MO. */ + signals = atomic_load_acquire (cond->__data.__g_signals + g); +- g1_start = __condvar_load_g1_start_relaxed (cond); +- lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; ++ g1_start = __condvar_load_g1_start_relaxed (cond); ++ lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; + spin--; + } + +- if (seq < (g1_start >> 1)) ++ if (seq < (g1_start >> 1)) + { +- /* If the group is closed already, ++ /* If the group is closed already, + then this waiter originally had enough extra signals to + consume, up until the time its group was closed. */ + goto done; +- } ++ } + + /* If there is an available signal, don't block. +- If __g1_start has advanced at all, then we must be in G1 ++ If __g1_start has advanced at all, then we must be in G1 + by now, perhaps in the process of switching back to an older + G2, but in either case we're allowed to consume the available + signal and should not block anymore. */ +@@ -483,22 +483,23 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, + sequence. */ + atomic_fetch_add_acquire (cond->__data.__g_refs + g, 2); + signals = atomic_load_acquire (cond->__data.__g_signals + g); +- g1_start = __condvar_load_g1_start_relaxed (cond); +- lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; ++ g1_start = __condvar_load_g1_start_relaxed (cond); ++ lowseq = (g1_start & 1) == g ? signals : g1_start & ~1U; + +- if (seq < (g1_start >> 1)) ++ if (seq < (g1_start >> 1)) + { +- /* group is closed already, so don't block */ ++ /* group is closed already, so don't block */ + __condvar_dec_grefs (cond, g, private); + goto done; + } + + if ((int)(signals - lowseq) >= 2) + { +- /* a signal showed up or G1/G2 switched after we grabbed the refcount */ ++ /* a signal showed up or G1/G2 switched after we grabbed the ++ refcount */ + __condvar_dec_grefs (cond, g, private); + break; +- } ++ } + + // Now block. + struct _pthread_cleanup_buffer buffer; +@@ -536,10 +537,8 @@ __pthread_cond_wait_common (pthread_cond_t *cond, pthread_mutex_t *mutex, + if (seq < (__condvar_load_g1_start_relaxed (cond) >> 1)) + goto done; + } +- /* Try to grab a signal. Use acquire MO so that we see an up-to-date value +- of __g1_start below (see spinning above for a similar case). In +- particular, if we steal from a more recent group, we will also see a +- more recent __g1_start below. */ ++ /* Try to grab a signal. See above for MO. (if we do another loop ++ iteration we need to see the correct value of g1_start) */ + while (!atomic_compare_exchange_weak_acquire (cond->__data.__g_signals + g, + &signals, signals - 2)); + +-- +2.49.0 + diff --git a/meta/recipes-core/glibc/glibc_2.35.bb b/meta/recipes-core/glibc/glibc_2.35.bb index 15179899d4..732cb96f94 100644 --- a/meta/recipes-core/glibc/glibc_2.35.bb +++ b/meta/recipes-core/glibc/glibc_2.35.bb @@ -63,6 +63,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \ file://0023-timezone-Make-shell-interpreter-overridable-in-tzsel.patch \ file://0024-fix-create-thread-failed-in-unprivileged-process-BZ-.patch \ file://0026-PR25847-1.patch \ + file://0026-PR25847-2.patch \ \ file://0001-Revert-Linux-Implement-a-useful-version-of-_startup_.patch \ file://0002-get_nscd_addresses-Fix-subscript-typos-BZ-29605.patch \