[tip:x86/asm] x86/asm/entry/32: Reinstate clearing of pt_regs-> r8..r11 on EFAULT path
Commit-ID: eb47854415825a69b1c578e7487da571227ba25a Gitweb: http://git.kernel.org/tip/eb47854415825a69b1c578e7487da571227ba25a Author: Denys Vlasenko AuthorDate: Sun, 7 Jun 2015 20:24:30 +0200 Committer: Ingo Molnar CommitDate: Mon, 8 Jun 2015 23:43:37 +0200 x86/asm/entry/32: Reinstate clearing of pt_regs->r8..r11 on EFAULT path I broke this recently when I changed pt_regs->r8..r11 clearing logic in INT 80 code path. There is a branch from SYSENTER/SYSCALL code to INT 80 code: if we fail to retrieve arg6, we return EFAULT. Before this patch, in this case we don't clear pt_regs->r8..r11. This patch fixes this. The resulting code is smaller and simpler. While at it, remove incorrect comment about syscall dispatching CALL insn: it does not use RIP-relative addressing form (the comment was meant to be "TODO: make this rip-relative", and morphed since then, dropping "TODO"). Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Will Drewry Link: http://lkml.kernel.org/r/1433701470-28800-1-git-send-email-dvlas...@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/entry/entry_64_compat.S | 8 ++-- 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 59840e3..5757dde 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -413,9 +413,7 @@ END(entry_SYSCALL_compat) ia32_badarg: ASM_CLAC - movq$-EFAULT, %rax - jmp ia32_sysret - + movq$-EFAULT, RAX(%rsp) ia32_ret_from_sys_call: xorl%eax, %eax /* Do not leak kernel information */ movq%rax, R11(%rsp) @@ -486,9 +484,7 @@ ia32_do_call: cmpq$(IA32_NR_syscalls-1), %rax ja 1f - call*ia32_sys_call_table(, %rax, 8) /* RIP relative */ - -ia32_sysret: + call*ia32_sys_call_table(, %rax, 8) movq%rax, RAX(%rsp) 1: jmp int_ret_from_sys_call -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[tip:x86/asm] x86/asm/entry/32: Reinstate clearing of pt_regs- r8..r11 on EFAULT path
Commit-ID: eb47854415825a69b1c578e7487da571227ba25a Gitweb: http://git.kernel.org/tip/eb47854415825a69b1c578e7487da571227ba25a Author: Denys Vlasenko dvlas...@redhat.com AuthorDate: Sun, 7 Jun 2015 20:24:30 +0200 Committer: Ingo Molnar mi...@kernel.org CommitDate: Mon, 8 Jun 2015 23:43:37 +0200 x86/asm/entry/32: Reinstate clearing of pt_regs-r8..r11 on EFAULT path I broke this recently when I changed pt_regs-r8..r11 clearing logic in INT 80 code path. There is a branch from SYSENTER/SYSCALL code to INT 80 code: if we fail to retrieve arg6, we return EFAULT. Before this patch, in this case we don't clear pt_regs-r8..r11. This patch fixes this. The resulting code is smaller and simpler. While at it, remove incorrect comment about syscall dispatching CALL insn: it does not use RIP-relative addressing form (the comment was meant to be TODO: make this rip-relative, and morphed since then, dropping TODO). Signed-off-by: Denys Vlasenko dvlas...@redhat.com Cc: Alexei Starovoitov a...@plumgrid.com Cc: Andrew Morton a...@linux-foundation.org Cc: Andy Lutomirski l...@amacapital.net Cc: Borislav Petkov b...@alien8.de Cc: Frederic Weisbecker fweis...@gmail.com Cc: H. Peter Anvin h...@zytor.com Cc: Kees Cook keesc...@chromium.org Cc: Linus Torvalds torva...@linux-foundation.org Cc: Oleg Nesterov o...@redhat.com Cc: Peter Zijlstra pet...@infradead.org Cc: Steven Rostedt rost...@goodmis.org Cc: Thomas Gleixner t...@linutronix.de Cc: Will Drewry w...@chromium.org Link: http://lkml.kernel.org/r/1433701470-28800-1-git-send-email-dvlas...@redhat.com Signed-off-by: Ingo Molnar mi...@kernel.org --- arch/x86/entry/entry_64_compat.S | 8 ++-- 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 59840e3..5757dde 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -413,9 +413,7 @@ END(entry_SYSCALL_compat) ia32_badarg: ASM_CLAC - movq$-EFAULT, %rax - jmp ia32_sysret - + movq$-EFAULT, RAX(%rsp) ia32_ret_from_sys_call: xorl%eax, %eax /* Do not leak kernel information */ movq%rax, R11(%rsp) @@ -486,9 +484,7 @@ ia32_do_call: cmpq$(IA32_NR_syscalls-1), %rax ja 1f - call*ia32_sys_call_table(, %rax, 8) /* RIP relative */ - -ia32_sysret: + call*ia32_sys_call_table(, %rax, 8) movq%rax, RAX(%rsp) 1: jmp int_ret_from_sys_call -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
