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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-03-10 17:57:07 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-03-26 23:19:43 +1100 |
| commit | 93c043e393af7fa218c928d8c62396ba28f1bb84 (patch) | |
| tree | f6abc072be71a0edc7a4b6360c1783c5379221cc /arch/powerpc/kernel/ptrace/ptrace-view.c | |
| parent | 870779f40e99c795ddfafa0dfc43318e51f15127 (diff) | |
| download | linux-93c043e393af7fa218c928d8c62396ba28f1bb84.tar.bz2 | |
powerpc/ptrace: Convert gpr32_set_common() to user access block
Use user access block in gpr32_set_common() instead of
repetitive __get_user() which imply repetitive KUAP open/close.
To get it clean, force inlining of the small set of tiny functions
called inside the block.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bdcb8652c3bb4ab5b8b3bfd08147434be8fc04c9.1615398498.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel/ptrace/ptrace-view.c')
| -rw-r--r-- | arch/powerpc/kernel/ptrace/ptrace-view.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c index 2bad8068f598..0923c94f684e 100644 --- a/arch/powerpc/kernel/ptrace/ptrace-view.c +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c @@ -111,7 +111,7 @@ static unsigned long get_user_msr(struct task_struct *task) return task->thread.regs->msr | task->thread.fpexc_mode; } -static int set_user_msr(struct task_struct *task, unsigned long msr) +static __always_inline int set_user_msr(struct task_struct *task, unsigned long msr) { task->thread.regs->msr &= ~MSR_DEBUGCHANGE; task->thread.regs->msr |= msr & MSR_DEBUGCHANGE; @@ -147,7 +147,7 @@ static int set_user_dscr(struct task_struct *task, unsigned long dscr) * We prevent mucking around with the reserved area of trap * which are used internally by the kernel. */ -static int set_user_trap(struct task_struct *task, unsigned long trap) +static __always_inline int set_user_trap(struct task_struct *task, unsigned long trap) { set_trap(task->thread.regs, trap); return 0; @@ -661,6 +661,9 @@ int gpr32_set_common(struct task_struct *target, const compat_ulong_t __user *u = ubuf; compat_ulong_t reg; + if (!kbuf && !user_read_access_begin(u, count)) + return -EFAULT; + pos /= sizeof(reg); count /= sizeof(reg); @@ -669,8 +672,7 @@ int gpr32_set_common(struct task_struct *target, regs[pos++] = *k++; else for (; count > 0 && pos < PT_MSR; --count) { - if (__get_user(reg, u++)) - return -EFAULT; + unsafe_get_user(reg, u++, Efault); regs[pos++] = reg; } @@ -678,8 +680,8 @@ int gpr32_set_common(struct task_struct *target, if (count > 0 && pos == PT_MSR) { if (kbuf) reg = *k++; - else if (__get_user(reg, u++)) - return -EFAULT; + else + unsafe_get_user(reg, u++, Efault); set_user_msr(target, reg); ++pos; --count; @@ -692,24 +694,24 @@ int gpr32_set_common(struct task_struct *target, ++k; } else { for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) { - if (__get_user(reg, u++)) - return -EFAULT; + unsafe_get_user(reg, u++, Efault); regs[pos++] = reg; } for (; count > 0 && pos < PT_TRAP; --count, ++pos) - if (__get_user(reg, u++)) - return -EFAULT; + unsafe_get_user(reg, u++, Efault); } if (count > 0 && pos == PT_TRAP) { if (kbuf) reg = *k++; - else if (__get_user(reg, u++)) - return -EFAULT; + else + unsafe_get_user(reg, u++, Efault); set_user_trap(target, reg); ++pos; --count; } + if (!kbuf) + user_read_access_end(); kbuf = k; ubuf = u; @@ -717,6 +719,10 @@ int gpr32_set_common(struct task_struct *target, count *= sizeof(reg); return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, (PT_TRAP + 1) * sizeof(reg), -1); + +Efault: + user_read_access_end(); + return -EFAULT; } static int gpr32_get(struct task_struct *target, |