[PATCH v2 03/17] vdso: Add __arch_get_k_vdso_rng_data()
From: Christophe Leroy <hidden>
Date: 2024-08-22 07:13:40
Also in:
linux-arch, linux-fsdevel, linux-kselftest, linux-mm, linuxppc-dev, lkml
Subsystem:
random number driver, the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
"Theodore Ts'o", Jason A. Donenfeld, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
_vdso_data is specific to x86 and __arch_get_k_vdso_data() is provided so that all architectures can provide the requested pointer. Do the same with _vdso_rng_data, provide __arch_get_k_vdso_rng_data() and don't use x86 _vdso_rng_data directly. Until now vdso/vsyscall.h was only included by time/vsyscall.c but now it will also be included in char/random.c, leading to a duplicate declaration of _vdso_data and _vdso_rng_data. To fix this issue, move declaration in a C file. vma.c looks like the most appropriate candidate. Don't need to replace the definitions in vsyscall.h by declarations as declarations are already in asm/vvar.h Signed-off-by: Christophe Leroy <redacted> --- v2: Move x86 DEFINE_VVAR(_vdso_data) and DEFINE_VVAR(_vdso_rng_data) in vma.c --- arch/x86/entry/vdso/vma.c | 3 +++ arch/x86/include/asm/vdso/vsyscall.h | 10 +++++++--- drivers/char/random.c | 5 +++-- 3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 6d83ceb7f1ba..b8fed8b8b9cc 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c@@ -38,6 +38,9 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page) } #undef EMIT_VVAR +DEFINE_VVAR(struct vdso_data, _vdso_data); +DEFINE_VVAR_SINGLE(struct vdso_rng_data, _vdso_rng_data); + unsigned int vclocks_used __read_mostly; #if defined(CONFIG_X86_64)
diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h
index 972415a8be31..67fedf1698b5 100644
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h@@ -9,9 +9,6 @@ #include <asm/vgtod.h> #include <asm/vvar.h> -DEFINE_VVAR(struct vdso_data, _vdso_data); -DEFINE_VVAR_SINGLE(struct vdso_rng_data, _vdso_rng_data); - /* * Update the vDSO data page to keep in sync with kernel timekeeping. */
@@ -22,6 +19,13 @@ struct vdso_data *__x86_get_k_vdso_data(void) } #define __arch_get_k_vdso_data __x86_get_k_vdso_data +static __always_inline +struct vdso_rng_data *__x86_get_k_vdso_rng_data(void) +{ + return &_vdso_rng_data; +} +#define __arch_get_k_vdso_rng_data __x86_get_k_vdso_rng_data + /* The asm-generic header needs to be included after the definitions above */ #include <asm-generic/vdso/vsyscall.h>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 87fe61295ea1..77968309e2c2 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c@@ -59,6 +59,7 @@ #ifdef CONFIG_VDSO_GETRANDOM #include <vdso/getrandom.h> #include <vdso/datapage.h> +#include <vdso/vsyscall.h> #endif #include <asm/archrandom.h> #include <asm/processor.h>
@@ -282,7 +283,7 @@ static void crng_reseed(struct work_struct *work) * is ordered with the write above to base_crng.generation. Pairs with * the smp_rmb() before the syscall in the vDSO code. */ - smp_store_release(&_vdso_rng_data.generation, next_gen + 1); + smp_store_release(&__arch_get_k_vdso_rng_data()->generation, next_gen + 1); #endif if (!static_branch_likely(&crng_is_ready)) crng_init = CRNG_READY;
@@ -735,7 +736,7 @@ static void __cold _credit_init_bits(size_t bits) queue_work(system_unbound_wq, &set_ready); atomic_notifier_call_chain(&random_ready_notifier, 0, NULL); #ifdef CONFIG_VDSO_GETRANDOM - WRITE_ONCE(_vdso_rng_data.is_ready, true); + WRITE_ONCE(__arch_get_k_vdso_rng_data()->is_ready, true); #endif wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN);
--
2.44.0