From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/ptrace: Split gpr32_set_common Date: Wed, 21 Jun 2023 12:37:19 +0200 [thread overview] Message-ID: <3086d189fa629e6c7bf800832921669450cc09bf.1687343697.git.christophe.leroy@csgroup.eu> (raw) objtool report the following warning: arch/powerpc/kernel/ptrace/ptrace-view.o: warning: objtool: gpr32_set_common+0x23c (.text+0x860): redundant UACCESS disable gpr32_set_common() conditionnaly opens and closes UACCESS based on whether kbuf point is NULL or not. This is wackelig. Split gpr32_set_common() in two fonctions, one for user one for kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/ptrace/ptrace-view.c | 106 ++++++++++++++--------- 1 file changed, 67 insertions(+), 39 deletions(-) diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c index 3910cd7bb2d9..1b0c2a234a7e 100644 --- a/arch/powerpc/kernel/ptrace/ptrace-view.c +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c @@ -716,73 +716,89 @@ int gpr32_get_common(struct task_struct *target, return membuf_zero(&to, (ELF_NGREG - PT_REGS_COUNT) * sizeof(u32)); } -int gpr32_set_common(struct task_struct *target, - const struct user_regset *regset, - unsigned int pos, unsigned int count, - const void *kbuf, const void __user *ubuf, - unsigned long *regs) +int gpr32_set_common_kernel(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, unsigned long *regs) { const compat_ulong_t *k = kbuf; + + pos /= sizeof(compat_ulong_t); + count /= sizeof(compat_ulong_t); + + for (; count > 0 && pos < PT_MSR; --count) + regs[pos++] = *k++; + + if (count > 0 && pos == PT_MSR) { + set_user_msr(target, *k++); + ++pos; + --count; + } + + for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) + regs[pos++] = *k++; + for (; count > 0 && pos < PT_TRAP; --count, ++pos) + ++k; + + if (count > 0 && pos == PT_TRAP) { + set_user_trap(target, *k++); + ++pos; + --count; + } + + kbuf = k; + pos *= sizeof(compat_ulong_t); + count *= sizeof(compat_ulong_t); + user_regset_copyin_ignore(&pos, &count, &kbuf, NULL, + (PT_TRAP + 1) * sizeof(compat_ulong_t), -1); + return 0; +} + +int gpr32_set_common_user(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void __user *ubuf, unsigned long *regs) +{ const compat_ulong_t __user *u = ubuf; compat_ulong_t reg; - if (!kbuf && !user_read_access_begin(u, count)) + if (!user_read_access_begin(u, count)) return -EFAULT; pos /= sizeof(reg); count /= sizeof(reg); - if (kbuf) - for (; count > 0 && pos < PT_MSR; --count) - regs[pos++] = *k++; - else - for (; count > 0 && pos < PT_MSR; --count) { - unsafe_get_user(reg, u++, Efault); - regs[pos++] = reg; - } - + for (; count > 0 && pos < PT_MSR; --count) { + unsafe_get_user(reg, u++, Efault); + regs[pos++] = reg; + } if (count > 0 && pos == PT_MSR) { - if (kbuf) - reg = *k++; - else - unsafe_get_user(reg, u++, Efault); + unsafe_get_user(reg, u++, Efault); set_user_msr(target, reg); ++pos; --count; } - if (kbuf) { - for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) - regs[pos++] = *k++; - for (; count > 0 && pos < PT_TRAP; --count, ++pos) - ++k; - } else { - for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) { - unsafe_get_user(reg, u++, Efault); - regs[pos++] = reg; - } - for (; count > 0 && pos < PT_TRAP; --count, ++pos) - unsafe_get_user(reg, u++, Efault); + for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) { + unsafe_get_user(reg, u++, Efault); + regs[pos++] = reg; } + for (; count > 0 && pos < PT_TRAP; --count, ++pos) + unsafe_get_user(reg, u++, Efault); if (count > 0 && pos == PT_TRAP) { - if (kbuf) - reg = *k++; - else - unsafe_get_user(reg, u++, Efault); + unsafe_get_user(reg, u++, Efault); set_user_trap(target, reg); ++pos; --count; } - if (!kbuf) - user_read_access_end(); + user_read_access_end(); - kbuf = k; ubuf = u; pos *= sizeof(reg); count *= sizeof(reg); - user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + user_regset_copyin_ignore(&pos, &count, NULL, &ubuf, (PT_TRAP + 1) * sizeof(reg), -1); return 0; @@ -791,6 +807,18 @@ int gpr32_set_common(struct task_struct *target, return -EFAULT; } +int gpr32_set_common(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf, + unsigned long *regs) +{ + if (kbuf) + return gpr32_set_common_kernel(target, regset, pos, count, kbuf, regs); + else + return gpr32_set_common_user(target, regset, pos, count, ubuf, regs); +} + static int gpr32_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) -- 2.40.1
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu> To: Michael Ellerman <mpe@ellerman.id.au>, Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/ptrace: Split gpr32_set_common Date: Wed, 21 Jun 2023 12:37:19 +0200 [thread overview] Message-ID: <3086d189fa629e6c7bf800832921669450cc09bf.1687343697.git.christophe.leroy@csgroup.eu> (raw) objtool report the following warning: arch/powerpc/kernel/ptrace/ptrace-view.o: warning: objtool: gpr32_set_common+0x23c (.text+0x860): redundant UACCESS disable gpr32_set_common() conditionnaly opens and closes UACCESS based on whether kbuf point is NULL or not. This is wackelig. Split gpr32_set_common() in two fonctions, one for user one for kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/ptrace/ptrace-view.c | 106 ++++++++++++++--------- 1 file changed, 67 insertions(+), 39 deletions(-) diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c index 3910cd7bb2d9..1b0c2a234a7e 100644 --- a/arch/powerpc/kernel/ptrace/ptrace-view.c +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c @@ -716,73 +716,89 @@ int gpr32_get_common(struct task_struct *target, return membuf_zero(&to, (ELF_NGREG - PT_REGS_COUNT) * sizeof(u32)); } -int gpr32_set_common(struct task_struct *target, - const struct user_regset *regset, - unsigned int pos, unsigned int count, - const void *kbuf, const void __user *ubuf, - unsigned long *regs) +int gpr32_set_common_kernel(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, unsigned long *regs) { const compat_ulong_t *k = kbuf; + + pos /= sizeof(compat_ulong_t); + count /= sizeof(compat_ulong_t); + + for (; count > 0 && pos < PT_MSR; --count) + regs[pos++] = *k++; + + if (count > 0 && pos == PT_MSR) { + set_user_msr(target, *k++); + ++pos; + --count; + } + + for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) + regs[pos++] = *k++; + for (; count > 0 && pos < PT_TRAP; --count, ++pos) + ++k; + + if (count > 0 && pos == PT_TRAP) { + set_user_trap(target, *k++); + ++pos; + --count; + } + + kbuf = k; + pos *= sizeof(compat_ulong_t); + count *= sizeof(compat_ulong_t); + user_regset_copyin_ignore(&pos, &count, &kbuf, NULL, + (PT_TRAP + 1) * sizeof(compat_ulong_t), -1); + return 0; +} + +int gpr32_set_common_user(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void __user *ubuf, unsigned long *regs) +{ const compat_ulong_t __user *u = ubuf; compat_ulong_t reg; - if (!kbuf && !user_read_access_begin(u, count)) + if (!user_read_access_begin(u, count)) return -EFAULT; pos /= sizeof(reg); count /= sizeof(reg); - if (kbuf) - for (; count > 0 && pos < PT_MSR; --count) - regs[pos++] = *k++; - else - for (; count > 0 && pos < PT_MSR; --count) { - unsafe_get_user(reg, u++, Efault); - regs[pos++] = reg; - } - + for (; count > 0 && pos < PT_MSR; --count) { + unsafe_get_user(reg, u++, Efault); + regs[pos++] = reg; + } if (count > 0 && pos == PT_MSR) { - if (kbuf) - reg = *k++; - else - unsafe_get_user(reg, u++, Efault); + unsafe_get_user(reg, u++, Efault); set_user_msr(target, reg); ++pos; --count; } - if (kbuf) { - for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) - regs[pos++] = *k++; - for (; count > 0 && pos < PT_TRAP; --count, ++pos) - ++k; - } else { - for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) { - unsafe_get_user(reg, u++, Efault); - regs[pos++] = reg; - } - for (; count > 0 && pos < PT_TRAP; --count, ++pos) - unsafe_get_user(reg, u++, Efault); + for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) { + unsafe_get_user(reg, u++, Efault); + regs[pos++] = reg; } + for (; count > 0 && pos < PT_TRAP; --count, ++pos) + unsafe_get_user(reg, u++, Efault); if (count > 0 && pos == PT_TRAP) { - if (kbuf) - reg = *k++; - else - unsafe_get_user(reg, u++, Efault); + unsafe_get_user(reg, u++, Efault); set_user_trap(target, reg); ++pos; --count; } - if (!kbuf) - user_read_access_end(); + user_read_access_end(); - kbuf = k; ubuf = u; pos *= sizeof(reg); count *= sizeof(reg); - user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, + user_regset_copyin_ignore(&pos, &count, NULL, &ubuf, (PT_TRAP + 1) * sizeof(reg), -1); return 0; @@ -791,6 +807,18 @@ int gpr32_set_common(struct task_struct *target, return -EFAULT; } +int gpr32_set_common(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf, + unsigned long *regs) +{ + if (kbuf) + return gpr32_set_common_kernel(target, regset, pos, count, kbuf, regs); + else + return gpr32_set_common_user(target, regset, pos, count, ubuf, regs); +} + static int gpr32_get(struct task_struct *target, const struct user_regset *regset, struct membuf to) -- 2.40.1
next reply other threads:[~2023-06-21 10:38 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-06-21 10:37 Christophe Leroy [this message] 2023-06-21 10:37 ` [PATCH] powerpc/ptrace: Split gpr32_set_common Christophe Leroy 2023-06-21 11:57 ` kernel test robot 2023-06-21 11:57 ` kernel test robot 2023-06-21 12:39 ` kernel test robot 2023-06-21 12:39 ` kernel test robot
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