When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com --- arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; }
-static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id, struct arm_smccc_res *res, struct kvm_cpu_context *ctxt) { @@ -461,6 +461,11 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id, goto out_unlock; }
+ if (len > ffa_desc_buf.len) { + ret = FFA_RET_NO_MEMORY; + goto out_unlock; + } + buf = hyp_buffers.tx; memcpy(buf, host_buffers.tx, fraglen);
Hi Snehal,
On Mon, Sep 09, 2024 at 06:01:54PM +0000, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com
Next time around, please include some notes on what's changed between versions and ideally a link to the last patch. It helps latecomers (i.e. me) get an idea of what's happening w/ a patch.
arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id, struct arm_smccc_res *res, struct kvm_cpu_context *ctxt) { @@ -461,6 +461,11 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id, goto out_unlock; }
- if (len > ffa_desc_buf.len) {
ret = FFA_RET_NO_MEMORY;goto out_unlock;- }
This check doesn't need to happen behind the host_buffers spinlock. Of course, keeping it behind the lock is benign, but this sort of thing prompts a reviewer to ask "why?"
Besides that,
Reviewed-by: Oliver Upton oliver.upton@linux.dev
On Mon, 09 Sep 2024 18:01:54 +0000, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
[...]
Applied to next, thanks!
[1/1] KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer commit: 39dacbeeee703d29140aca7bc2826d4b1936ecb6
Cheers,
M.
Hi everyone,
On Mon, Sep 09, 2024 at 06:01:54PM GMT, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com
arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id,
I am seeing a compilation error because of this.
----- LOG START ----- $ clang --version clang version 18.1.8 Target: x86_64-pc-linux-gnu Thread model: posix InstalledDir: /usr/bin $ make LLVM=1 ARCH=arm64 defconfig $ make LLVM=1 ARCH=arm64 Image ... arch/arm64/kvm/hyp/nvhe/ffa.c:443:2: error: call to '__compiletime_assert_776' declared with 'error' attribute: BUILD_BUG_ON failed: func_id != FFA_FN64_MEM_SHARE && func_id != FFA_FN64_MEM_LEND 443 | BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE && | ^ ./include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON' 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^ ./include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^ ././include/linux/compiler_types.h:510:2: note: expanded from macro 'compiletime_assert' 510 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ ././include/linux/compiler_types.h:498:2: note: expanded from macro '_compiletime_assert' 498 | __compiletime_assert(condition, msg, prefix, suffix) | ^ ././include/linux/compiler_types.h:491:4: note: expanded from macro '__compiletime_assert' 491 | prefix ## suffix(); \ | ^ <scratch space>:66:1: note: expanded from here 66 | __compiletime_assert_776 | ^ 1 error generated. make[6]: *** [arch/arm64/kvm/hyp/nvhe/Makefile:46: arch/arm64/kvm/hyp/nvhe/ffa.nvhe.o] Error 1 make[5]: *** [scripts/Makefile.build:485: arch/arm64/kvm/hyp/nvhe] Error 2 make[4]: *** [scripts/Makefile.build:485: arch/arm64/kvm/hyp] Error 2 make[3]: *** [scripts/Makefile.build:485: arch/arm64/kvm] Error 2 make[3]: *** Waiting for unfinished jobs.... ----- LOG END -----
Is this expected? Because when I add back the __always_inline, or change the BUILD_BUG_ON to BUG_ON, it compiles successfully.
Thanks, Wei-Lin Chang
struct arm_smccc_res *res, struct kvm_cpu_context *ctxt){ @@ -461,6 +461,11 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id, goto out_unlock; }
- if (len > ffa_desc_buf.len) {
ret = FFA_RET_NO_MEMORY;goto out_unlock;- }
- buf = hyp_buffers.tx; memcpy(buf, host_buffers.tx, fraglen);
2.46.0.598.g6f2099f65c-goog
On Wed, Sep 11, 2024 at 12:32:29AM +0800, Wei-Lin Chang wrote:
Hi everyone,
On Mon, Sep 09, 2024 at 06:01:54PM GMT, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com
arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id,
I am seeing a compilation error because of this.
Thanks for reporting this. Looks like the __always_inline was slightly more load bearing...
Marc, can you put something like this on top?
From c2712eaa94989ae6457baad3ec459cf363ec5119 Mon Sep 17 00:00:00 2001 From: Oliver Upton oliver.upton@linux.dev Date: Tue, 10 Sep 2024 16:45:30 +0000 Subject: [PATCH] KVM: arm64: Drop BUILD_BUG_ON() from do_ffa_mem_xfer()
__always_inline was recently discarded from do_ffa_mem_xfer() since it appeared to be unnecessary. Of course, this was ~immediately proven wrong, as the compile-time check against @func_id depends on inlining for the value to be known.
Just downgrade to a WARN_ON() instead of putting the old mess back in place. Fix the wrapping/indentation of the function parameters while at it.
Fixes: 39dacbeeee70 ("KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer") Reported-by: Wei-Lin Chang r09922117@csie.ntu.edu.tw Signed-off-by: Oliver Upton oliver.upton@linux.dev --- arch/arm64/kvm/hyp/nvhe/ffa.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 637425f63fd1..316d269341f3 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,9 +426,8 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; }
-static void do_ffa_mem_xfer(const u64 func_id, - struct arm_smccc_res *res, - struct kvm_cpu_context *ctxt) +static void do_ffa_mem_xfer(const u64 func_id, struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) { DECLARE_REG(u32, len, ctxt, 1); DECLARE_REG(u32, fraglen, ctxt, 2); @@ -440,8 +439,10 @@ static void do_ffa_mem_xfer(const u64 func_id, u32 offset, nr_ranges; int ret = 0;
- BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE && - func_id != FFA_FN64_MEM_LEND); + if (WARN_ON(func_id != FFA_FN64_MEM_SHARE && func_id != FFA_FN64_MEM_LEND)) { + ret = SMCCC_RET_NOT_SUPPORTED; + goto out; + }
if (addr_mbz || npages_mbz || fraglen > len || fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
On Tue, 10 Sep 2024 19:18:41 +0100, Oliver Upton oliver.upton@linux.dev wrote:
On Wed, Sep 11, 2024 at 12:32:29AM +0800, Wei-Lin Chang wrote:
Hi everyone,
On Mon, Sep 09, 2024 at 06:01:54PM GMT, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com
arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id,
I am seeing a compilation error because of this.
Thanks for reporting this. Looks like the __always_inline was slightly more load bearing...
Marc, can you put something like this on top?
From c2712eaa94989ae6457baad3ec459cf363ec5119 Mon Sep 17 00:00:00 2001 From: Oliver Upton oliver.upton@linux.dev Date: Tue, 10 Sep 2024 16:45:30 +0000 Subject: [PATCH] KVM: arm64: Drop BUILD_BUG_ON() from do_ffa_mem_xfer()
__always_inline was recently discarded from do_ffa_mem_xfer() since it appeared to be unnecessary. Of course, this was ~immediately proven wrong, as the compile-time check against @func_id depends on inlining for the value to be known.
Just downgrade to a WARN_ON() instead of putting the old mess back in place. Fix the wrapping/indentation of the function parameters while at it.
Fixes: 39dacbeeee70 ("KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer") Reported-by: Wei-Lin Chang r09922117@csie.ntu.edu.tw Signed-off-by: Oliver Upton oliver.upton@linux.dev
arch/arm64/kvm/hyp/nvhe/ffa.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 637425f63fd1..316d269341f3 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,9 +426,8 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static void do_ffa_mem_xfer(const u64 func_id,
struct arm_smccc_res *res,struct kvm_cpu_context *ctxt)+static void do_ffa_mem_xfer(const u64 func_id, struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt){ DECLARE_REG(u32, len, ctxt, 1); DECLARE_REG(u32, fraglen, ctxt, 2); @@ -440,8 +439,10 @@ static void do_ffa_mem_xfer(const u64 func_id, u32 offset, nr_ranges; int ret = 0;
- BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
func_id != FFA_FN64_MEM_LEND);
- if (WARN_ON(func_id != FFA_FN64_MEM_SHARE && func_id != FFA_FN64_MEM_LEND)) {
ret = SMCCC_RET_NOT_SUPPORTED;goto out;- }
I'm not overly on the WARN_ON(), as it has pretty fatal effects on pKVM (it simply panics). What do you think of this instead, which compiles with my prehistoric version of clang (14.0.6):
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 637425f63fd1b..e433dfab882aa 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,9 +426,9 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; }
-static void do_ffa_mem_xfer(const u64 func_id, - struct arm_smccc_res *res, - struct kvm_cpu_context *ctxt) +static void __do_ffa_mem_xfer(const u64 func_id, + struct arm_smccc_res *res, + struct kvm_cpu_context *ctxt) { DECLARE_REG(u32, len, ctxt, 1); DECLARE_REG(u32, fraglen, ctxt, 2); @@ -440,9 +440,6 @@ static void do_ffa_mem_xfer(const u64 func_id, u32 offset, nr_ranges; int ret = 0;
- BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE && - func_id != FFA_FN64_MEM_LEND); - if (addr_mbz || npages_mbz || fraglen > len || fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { ret = FFA_RET_INVALID_PARAMETERS; @@ -517,6 +514,13 @@ static void do_ffa_mem_xfer(const u64 func_id, goto out_unlock; }
+#define do_ffa_mem_xfer(fid, res, ctxt) \ + do { \ + BUILD_BUG_ON((fid) != FFA_FN64_MEM_SHARE && \ + (fid) != FFA_FN64_MEM_LEND); \ + __do_ffa_mem_xfer((fid), (res), (ctxt)); \ + } while (0); + static void do_ffa_mem_reclaim(struct arm_smccc_res *res, struct kvm_cpu_context *ctxt) {
It preserves the build-time assertion, which was the intention of the original author.
I can easily squash that in the original commit, avoiding the headache of backporting both patch to stable.
M.
On Tue, Sep 10, 2024 at 08:49:28PM +0100, Marc Zyngier wrote:
On Tue, 10 Sep 2024 19:18:41 +0100, Oliver Upton oliver.upton@linux.dev wrote:
On Wed, Sep 11, 2024 at 12:32:29AM +0800, Wei-Lin Chang wrote:
Hi everyone,
On Mon, Sep 09, 2024 at 06:01:54PM GMT, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
Also do_ffa_mem_xfer() does not need __always_inline
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host") Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ene sebastianene@google.com Signed-off-by: Snehal Koukuntla snehalreddy@google.com
arch/arm64/kvm/hyp/nvhe/ffa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index e715c157c2c4..637425f63fd1 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,7 +426,7 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static __always_inline void do_ffa_mem_xfer(const u64 func_id, +static void do_ffa_mem_xfer(const u64 func_id,
I am seeing a compilation error because of this.
Thanks for reporting this. Looks like the __always_inline was slightly more load bearing...
Marc, can you put something like this on top?
From c2712eaa94989ae6457baad3ec459cf363ec5119 Mon Sep 17 00:00:00 2001 From: Oliver Upton oliver.upton@linux.dev Date: Tue, 10 Sep 2024 16:45:30 +0000 Subject: [PATCH] KVM: arm64: Drop BUILD_BUG_ON() from do_ffa_mem_xfer()
__always_inline was recently discarded from do_ffa_mem_xfer() since it appeared to be unnecessary. Of course, this was ~immediately proven wrong, as the compile-time check against @func_id depends on inlining for the value to be known.
Just downgrade to a WARN_ON() instead of putting the old mess back in place. Fix the wrapping/indentation of the function parameters while at it.
Fixes: 39dacbeeee70 ("KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer") Reported-by: Wei-Lin Chang r09922117@csie.ntu.edu.tw Signed-off-by: Oliver Upton oliver.upton@linux.dev
arch/arm64/kvm/hyp/nvhe/ffa.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 637425f63fd1..316d269341f3 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -426,9 +426,8 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_res *res, return; } -static void do_ffa_mem_xfer(const u64 func_id,
struct arm_smccc_res *res,struct kvm_cpu_context *ctxt)+static void do_ffa_mem_xfer(const u64 func_id, struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt){ DECLARE_REG(u32, len, ctxt, 1); DECLARE_REG(u32, fraglen, ctxt, 2); @@ -440,8 +439,10 @@ static void do_ffa_mem_xfer(const u64 func_id, u32 offset, nr_ranges; int ret = 0;
- BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
func_id != FFA_FN64_MEM_LEND);
- if (WARN_ON(func_id != FFA_FN64_MEM_SHARE && func_id != FFA_FN64_MEM_LEND)) {
ret = SMCCC_RET_NOT_SUPPORTED;goto out;- }
I'm not overly on the WARN_ON(), as it has pretty fatal effects on pKVM (it simply panics).
It's unexpected, what else are you wanting? :P
What do you think of this instead, which compiles with my prehistoric version of clang (14.0.6):
LGTM, macro expansion makes the relation a bit more obvious. Feel free to add:
Reviewed-by: Oliver Upton oliver.upton@linux.dev
On Mon, 09 Sep 2024 18:01:54 +0000, Snehal Koukuntla wrote:
When we share memory through FF-A and the description of the buffers exceeds the size of the mapped buffer, the fragmentation API is used. The fragmentation API allows specifying chunks of descriptors in subsequent FF-A fragment calls and no upper limit has been established for this. The entire memory region transferred is identified by a handle which can be used to reclaim the transferred memory. To be able to reclaim the memory, the description of the buffers has to fit in the ffa_desc_buf. Add a bounds check on the FF-A sharing path to prevent the memory reclaim from failing.
[...]
Applied to next, with the BUILD_BUG_ON() issue fixed.
[1/1] KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer commit: f26a525b77e040d584e967369af1e018d2d59112
Cheers,
M.
linux-stable-mirror@lists.linaro.org
-
Marc Zyngier -
Oliver Upton -
Snehal Koukuntla -
Wei-Lin Chang