diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2023-06-05 10:58:35 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-06-09 23:29:51 +1000 |
| commit | a03b1a0b19398a47489fdcef02ec19c2ba05a15d (patch) | |
| tree | 6d4a1425de73dab09b62676b9353e454de503968 | |
| parent | 0eb089a72fda3f7969e6277804bde75dc1474a14 (diff) | |
powerpc/signal32: Force inlining of __unsafe_save_user_regs() and save_tm_user_regs_unsafe()
Looking at generated code for handle_signal32() shows calls to a
function called __unsafe_save_user_regs.constprop.0 while user access
is open.
And that __unsafe_save_user_regs.constprop.0 function has two nops at
the begining, allowing it to be traced, which is unexpected during
user access open window.
The solution could be to mark __unsafe_save_user_regs() no trace, but
to be on the safe side the most efficient is to flag it __always_inline
as already done for function __unsafe_restore_general_regs(). The
function is relatively small and only called twice, so the size
increase will remain in the noise.
Do the same with save_tm_user_regs_unsafe() as it may suffer the
same issue.
Fixes: ef75e7318294 ("powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/7e469c8f01860a69c1ada3ca6a5e2aa65f0f74b2.1685955220.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index c114c7f25645..7a718ed32b27 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -264,8 +264,9 @@ static void prepare_save_user_regs(int ctx_has_vsx_region) #endif } -static int __unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, int ctx_has_vsx_region) +static __always_inline int +__unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, int ctx_has_vsx_region) { unsigned long msr = regs->msr; @@ -364,8 +365,9 @@ static void prepare_save_tm_user_regs(void) current->thread.ckvrsave = mfspr(SPRN_VRSAVE); } -static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, unsigned long msr) +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) { /* Save both sets of general registers */ unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed); @@ -444,8 +446,9 @@ failed: #else static void prepare_save_tm_user_regs(void) { } -static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, - struct mcontext __user *tm_frame, unsigned long msr) +static __always_inline int +save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame, + struct mcontext __user *tm_frame, unsigned long msr) { return 0; } |