From: Hedi Berriche <hedi.berriche@hpe.com>
To: linux-kernel@vger.kernel.org,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Bhupesh Sharma <bhsharma@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
linux-efi@vger.kernel.org, x86@kernel.org,
Russ Anderson <rja@hpe.com>, Mike Travis <mike.travis@hpe.com>,
Dimitri Sivanich <sivanich@hpe.com>,
Steve Wahl <steve.wahl@hpe.com>,
stable@vger.kernel.org
Subject: [Patch v3 4/4] x86/platform/UV: use efi_runtime_lock to serialise BIOS calls
Date: Wed, 13 Feb 2019 19:34:13 +0000
Message-ID: <20190213193413.25560-5-hedi.berriche@hpe.com> (raw)
In-Reply-To: <20190213193413.25560-1-hedi.berriche@hpe.com>
Calls into UV firmware must be protected against concurrency, expose the
efi_runtime_lock to the UV platform, and use it to serialise UV BIOS calls.
Cc: Russ Anderson <rja@hpe.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Dimitri Sivanich <sivanich@hpe.com>
Cc: Steve Wahl <steve.wahl@hpe.com>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Hedi Berriche <hedi.berriche@hpe.com>
---
arch/x86/include/asm/uv/bios.h | 8 +++++++-
arch/x86/platform/uv/bios_uv.c | 23 +++++++++++++++++++++--
drivers/firmware/efi/runtime-wrappers.c | 7 +++++++
3 files changed, 35 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/uv/bios.h b/arch/x86/include/asm/uv/bios.h
index 8c6ac271b5b3..8cfccc3cbbf4 100644
--- a/arch/x86/include/asm/uv/bios.h
+++ b/arch/x86/include/asm/uv/bios.h
@@ -48,7 +48,8 @@ enum {
BIOS_STATUS_SUCCESS = 0,
BIOS_STATUS_UNIMPLEMENTED = -ENOSYS,
BIOS_STATUS_EINVAL = -EINVAL,
- BIOS_STATUS_UNAVAIL = -EBUSY
+ BIOS_STATUS_UNAVAIL = -EBUSY,
+ BIOS_STATUS_ABORT = -EINTR,
};
/* Address map parameters */
@@ -162,4 +163,9 @@ extern long system_serial_number;
extern struct kobject *sgi_uv_kobj; /* /sys/firmware/sgi_uv */
+/*
+ * EFI runtime lock; cf. firmware/efi/runtime-wrappers.c for details
+ */
+extern struct semaphore __efi_uv_runtime_lock;
+
#endif /* _ASM_X86_UV_BIOS_H */
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 38a2e3431fc6..ef60d789c76e 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -29,7 +29,8 @@
struct uv_systab *uv_systab;
-s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
+static s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,
+ u64 a4, u64 a5)
{
struct uv_systab *tab = uv_systab;
s64 ret;
@@ -51,6 +52,19 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
return ret;
}
+
+s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
+{
+ s64 ret;
+
+ if (down_interruptible(&__efi_uv_runtime_lock))
+ return BIOS_STATUS_ABORT;
+
+ ret = __uv_bios_call(which, a1, a2, a3, a4, a5);
+ up(&__efi_uv_runtime_lock);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(uv_bios_call);
s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,
@@ -59,10 +73,15 @@ s64 uv_bios_call_irqsave(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,
unsigned long bios_flags;
s64 ret;
+ if (down_interruptible(&__efi_uv_runtime_lock))
+ return BIOS_STATUS_ABORT;
+
local_irq_save(bios_flags);
- ret = uv_bios_call(which, a1, a2, a3, a4, a5);
+ ret = __uv_bios_call(which, a1, a2, a3, a4, a5);
local_irq_restore(bios_flags);
+ up(&__efi_uv_runtime_lock);
+
return ret;
}
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 8903b9ccfc2b..e2abfdb5cee6 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -146,6 +146,13 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call)
*/
static DEFINE_SEMAPHORE(efi_runtime_lock);
+/*
+ * Expose the EFI runtime lock to the UV platform
+ */
+#ifdef CONFIG_X86_UV
+extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);
+#endif
+
/*
* Calls the appropriate efi_runtime_service() with the appropriate
* arguments.
--
2.20.1
next prev parent reply index
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-13 19:34 [Patch v3 0/4] Protect against concurrent calls into UV BIOS Hedi Berriche
2019-02-13 19:34 ` [Patch v3 1/4] x86/platform/UV: remove unnecessary #ifdef CONFIG_EFI Hedi Berriche
2019-02-15 15:04 ` [tip:x86/uv] x86/platform/UV: Remove " tip-bot for Hedi Berriche
2019-02-13 19:34 ` [Patch v3 2/4] x86/platform/UV: kill uv_bios_call_reentrant() Hedi Berriche
2019-02-15 15:04 ` [tip:x86/uv] x86/platform/UV: Remove uv_bios_call_reentrant() tip-bot for Hedi Berriche
2019-02-13 19:34 ` [Patch v3 3/4] x86/platform/UV: use efi_enabled() instead of test_bit() Hedi Berriche
2019-02-15 15:05 ` [tip:x86/uv] x86/platform/UV: Use " tip-bot for Hedi Berriche
2019-02-13 19:34 ` Hedi Berriche [this message]
2019-02-15 15:01 ` [tip:x86/urgent] x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls tip-bot for Hedi Berriche
2019-02-14 8:17 ` [Patch v3 0/4] Protect against concurrent calls into UV BIOS Ard Biesheuvel
2019-02-14 21:08 ` Russ Anderson
2019-02-14 21:21 ` Dimitri Sivanich
2019-02-14 21:31 ` Mike Travis
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